WO2022224984A1

WO2022224984A1 - Reflective screen and video display device

Info

Publication number: WO2022224984A1
Application number: PCT/JP2022/018261
Authority: WO
Inventors: 弘小島; 正浩後藤; 博関口; 憲一坂本; 朋也川島
Original assignee: 大日本印刷株式会社
Priority date: 2021-04-20
Filing date: 2022-04-20
Publication date: 2022-10-27

Abstract

Provided are a reflective screen with which video glare can be reduced and clear video can be displayed, and a video display device comprising said reflective screen. Also provided are a reflective screen with which clear video with high contrast can be displayed, and a video display device comprising said reflective screen.　A screen 10 is a reflective screen and comprises: a first optical shape layer 12 in which a plurality of unit optical shapes 121 are arranged; a reflecting layer 13 that is formed on part of at least first inclines 121a of the unit optical shapes 121 and that diffusely reflects at least part of the incident light; and a light control layer 16 that is positioned closer to a video source than the reflecting layer 13, that diffuses and transmits light incident from a specific angle range, and that transmits light incident from outside the range without diffusing the light.

Description

Reflective screen, image display device

The present invention relates to a reflective screen and a video display device equipped with the same.

Conventionally, various types of reflective screens have been developed that reflect and display the image light projected from the image source. Among them, for example, a transparent reflective screen (see, for example, Patent Document 1) is fixed by being attached to a highly translucent member such as a window glass, and reflects projected image light. In addition, the scenery on the other side of the screen can be observed through the screen when the image light is not projected and the screen is not in use.

JP 2017-156452 A

As shown in Patent Document 1, when the reflective surface (the surface of the reflective layer) is a rough surface having fine irregularities, the image light is diffusely reflected by the reflective surface. It is not necessary to provide a light diffusing layer closer to the image source than the reflective layer, and the transparency of the reflective screen can be improved.
However, when such a rough reflective surface is provided, there is a problem that the image is likely to glare (also called speckle).

Such image glare is not preferable because it interferes with comfortable viewing of the image. In addition, such image glare tends to be visible particularly when using an image source using a laser light source capable of displaying a bright and clear image.
In order to reduce such image glare, it is effective to provide a light diffusion layer containing a diffusion material as described above. However, such a light diffusion layer has the problem of causing image blurring (reduction of resolution) and reducing the transparency of the screen.

In a transparent reflective screen, part of the image light passes through the reflective layer, is totally reflected at the interface on the back side of the screen, and is emitted toward the image source, resulting in images such as double images. There were cases where blurring occurred and the clarity of the image decreased.
In addition, with a reflective screen having transparency, black brightness of images tends to be high, and a decrease in image contrast is also a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a reflective screen capable of reducing image glare and displaying a clear image, and an image display device having the same.
Another object of the present invention is to provide a reflective screen capable of displaying a high-contrast, clear image, and an image display device having the same.

The present invention solves the above problems by means of the following solutions. In order to facilitate understanding, reference numerals corresponding to the embodiments of the present invention are used for explanation, but the present invention is not limited to these.
A first invention is a reflective screen that displays an image by reflecting at least part of image light projected from an image source, and has a first surface (121a) on which image light is incident and intersects this. a first optical shape layer (12) having a second surface (121b) and having a plurality of unit optical shapes (121) arranged convexly on the back side; and at least the first surface of the unit optical shape. A reflective layer (13) that diffusely reflects at least part of the incident light, and the reflective screen in the thickness direction of the reflective screen. Located closer to the image source than the reflective layer, it diffuses and transmits incident light from a specific angular range (R1), and transmits incident light from outside the specific angular range (R2) without diffusing it. and a light control layer (16) that does not have a light diffusion layer containing particles that diffuse light, and the first surface of the unit optical shape forms an angle α with a surface parallel to the screen surface increases in one direction along the direction in which the unit optical shapes are arranged, and the specific angular range extends in a direction parallel to the direction in which the unit optical shapes are arranged and passing through a point that is the center of the screen of the reflective screen. In a cross section parallel to the thickness direction of the reflective screen, the range is 25° or more and 55° or less to the side where the angle α is small with respect to a straight line perpendicular to the image source side surface of the light control layer. A reflective screen (10, 20) characterized by:
In a second invention, in the reflective screen of the first invention, in the thickness direction of the reflective screen, the image source side surface of the first optical shape layer (12) and the back surface of the light control layer (16) A reflective screen (10, 20) characterized in that the distance (D1) between the side surfaces is 0.5 mm or less.
A third aspect of the invention is a reflective screen that displays an image by reflecting at least a portion of image light projected from an image source, the screen intersecting with a first surface (121a) on which image light is incident. a first optical shape layer (12) having a second surface (121b) and having a plurality of unit optical shapes (121) arranged convexly on the back side; and at least the first surface of the unit optical shape. A reflective layer (13) that diffusely reflects at least part of the incident light, and the reflective screen in the thickness direction of the reflective screen. Located closer to the image source than the reflective layer, it diffuses and transmits incident light from a specific angular range (R1), and transmits incident light from outside the specific angular range (R2) without diffusing it. and a light control layer (16) that diffuses light, and does not have a light diffusion layer containing particles that diffuse light, and the first surface of the unit optical shape forms an angle α with a surface parallel to the screen surface , the angle range increases in one direction along the direction in which the unit optical shapes are arranged, and the specific angle range extends through a point that is the center of the screen of the reflective screen, in a direction parallel to the direction in which the unit optical shapes are arranged, and in the direction parallel to the direction in which the unit optical shapes are arranged. In a cross section parallel to the thickness direction of the pattern screen, the range is 25° or more and 55° or less to the side where the angle α is small with respect to a straight line perpendicular to the image source side surface of the light control layer, In the thickness direction of the reflective screen, the distance (D1) between the image source side surface of the first optical shape layer and the back surface side surface of the light control layer is greater than 0.5 mm and 8 mm or less. A reflective screen (40) characterized by:
A fourth invention is the reflective screen according to any one of the first invention to the third invention, wherein the reflective layer (13) reflects a part of the incident light and transmits a part of it. A second optic which is a mold, is provided adjacent to the reflective layer on the back side of the reflective layer, has optical transparency, and is laminated so as to fill the valleys of the adjacent unit optical shapes (121). It has a shaped layer (14), and the second optically shaped layer has a planar surface on the back side and has a refractive index that is equal to or equal to the refractive index of the first optically shaped layer (12). A reflective screen (10, 20, 40) characterized in that
A fifth invention is the reflective screen according to any one of the first invention to the fourth invention, wherein the first optical shape layer (12) has a Fresnel lens shape on the back side, and the unit optical shape (121) is arc-shaped when viewed from a direction orthogonal to the screen surface, and is arranged concentrically around a point located outside the display area of the reflective screen. (10, 20, 40).
A sixth invention is the reflective screen according to any one of the first invention to the fifth invention, comprising a light absorption layer (30) that partially absorbs and partially transmits incident light, A reflective screen (20, 40) characterized by
A seventh aspect of the invention is the reflective screen (20, 40).
In an eighth aspect of the invention, in the reflective screen of the seventh aspect, the light absorption layer (30) has a higher absorptivity for light with a large incident angle than that for light with an incident angle of 0°. , and a reflective screen (20, 40) characterized by being a light modulating layer capable of selecting a state in which the difference in light absorptance depending on the incident angle is small.
A ninth invention is the reflective screen according to any one of the sixth invention to the eighth invention, wherein the reflective layer (13) reflects a part of incident light and transmits a part of it, which is semi-transmissive. A second optical shape layer ( 14), and in the thickness direction of the reflective screen, the distance (D2) from the image source side surface of the light absorption layer (30) to the back side surface of the second optical shape layer (14) is , greater than the distance (D1) from the back side surface of the light control layer (16) to the image source side surface of the first optical shape layer (12). is.
A tenth invention is a reflective screen (10, 20, 40) according to any one of the first invention to the ninth invention, and an image source (LS) for projecting image light onto the reflective screen. It is a video display device (1) provided.
According to an eleventh invention, in the image display device according to the tenth invention, the specific angular range (R1) of the reflective screen (10, 20, 40) is an image light projected by the image source (LS). An image display device (1) characterized by including a main incident angle range.
A twelfth aspect of the present invention is a reflective screen for displaying an image by reflecting at least part of image light projected from an image source, the screen having a fine and irregular uneven shape formed on the surface thereof, and a transflective reflective layer (13) that diffuses and reflects at least a portion of light by the uneven shape and transmits a portion of the light; A light control layer (30) that absorbs a part of incident light and transmits a part of it so that the transmittance can be adjusted, and does not have a light diffusion layer that contains particles that diffuse light. A reflective screen (70, 20, 40, 80) characterized by:
A thirteenth invention is the reflective screen according to the twelfth invention, wherein the light control layer (30) comprises a layer (36) containing a liquid crystal material containing a dichroic dye. Mold screens (70, 20, 40, 80).
A fourteenth invention is the reflective screen according to the twelfth invention or the thirteenth invention, wherein the light control layer (30) absorbs light with an incident angle of 40° or more in a state of high light transmittance. A reflective screen (70, 20, 40, 80) characterized in that the index is greater than the absorption for light with an incident angle of 0°.
In a fifteenth aspect of the invention, in the reflective screen according to any one of the twelfth invention to the fourteenth invention, and a first optical shape layer (12) in which a plurality of unit optical shapes (121) that are convex on the back side are arranged; and a second optical shape layer (14) having optical transparency and laminated so as to fill the valleys of the adjacent unit optical shapes, wherein the reflective layer is at least the second optical shape of the unit optical shapes. 1, the second optically shaped layer has a flat rear surface, and has a refractive index equal to or so small that it can be regarded as equal to that of the first optically shaped layer. A reflective screen (70, 20, 40, 80) characterized by:
In a sixteenth invention based on the reflective screen according to the fifteenth invention, the first optical shape layer (12) has a Fresnel lens shape on the back surface side, and the unit optical shape is formed from a direction orthogonal to the screen surface. A reflective screen (70, 20, 40, 80) characterized by being arc-shaped when viewed and arranged concentrically around a point (C) located outside the display area of the reflective screen. is.
A seventeenth invention is the reflective screen according to any one of the twelfth invention to the sixteenth invention, wherein the light modulating layer (30) is laminated with a substrate layer having high light transmittance on the image source side or the back side. or sandwiched between two substrate layers (88, 89) having high light transmittance in the thickness direction.
In an eighteenth invention, in the reflective screen according to any one of the twelfth invention to the seventeenth invention, a specific A reflection characterized by comprising a light control layer (16) that diffuses and transmits incident light from an angular range (R1) and transmits incident light from outside the specific angular range without diffusion. Mold screens (20, 40).
A nineteenth invention is a reflective screen (70, 20, 40, 80) according to any one of the twelfth invention to the eighteenth invention, and an image source (LS) for projecting image light onto the reflective screen. A video display device (1) comprising:

Advantageous Effects of Invention According to the present invention, it is possible to provide a reflective screen capable of reducing image glare and displaying a clear image, and an image display device including the same.
Further, according to the present invention, it is possible to provide a reflective screen capable of displaying a clear image with high contrast, and an image display device having the same.

It is a figure which shows the video display apparatus 1 of 1st Embodiment. It is a figure which shows the layer structure of the screen 10 of 1st Embodiment. FIG. 4 is a diagram for explaining a first optical shape layer 12; 4A and 4B are diagrams for explaining the light control action of the light control layer 16; FIG. 4A and 4B are diagrams showing an example of image light and external light incident on the screen 10 of the first embodiment; FIG. FIG. 4 is a diagram showing the positions of each screen, image source LS, luminance meter K, observer O3, and the like during measurement of peak luminance and the like and visual evaluation. It is a figure which shows the layer structure of the screen 20 of 2nd Embodiment. 4 is a diagram showing the state of orientation of liquid crystal material of the light control layer 30. FIG. FIG. 7 is a diagram showing an example of image light and external light incident on the screen 20 of the second embodiment; FIG. 10 is a diagram showing a layer structure of a screen 40 of a third embodiment; FIG. FIG. 12 is a diagram showing an example of image light and external light incident on the screen 40 of the third embodiment; It is a figure which shows each screen at the time of visual evaluation, the image source LS, the position of the observer O3, etc. FIG. FIG. 11 is a diagram showing a layer structure of a screen 70 of a fourth embodiment; FIG. FIG. 4 is a diagram for explaining a method of measuring changes in transmittance depending on the incident angle in Samples 1 to 3; 4 is a graph showing the rate of decrease in obliquely incident light transmittance with respect to the front transmittance of Samples 1 to 3. FIG. FIG. 12 is a diagram showing an example of image light and external light incident on the screen 70 of the fourth embodiment; FIG. 11 is a diagram showing a layer structure of a screen 80 of a fifth embodiment; FIG. 5 is a diagram showing a layer configuration of a screen 50 of a modified form;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each figure shown below including FIG. 1 is a schematic diagram, and the size and shape of each part are appropriately exaggerated for easy understanding.
In this specification, terms that specify shapes and geometric conditions, such as parallel and orthogonal terms, have the same optical function and can be regarded as parallel or orthogonal in addition to the strict meaning. It shall include the state with an error of

In addition, in this specification, terms such as plate, sheet, and film are used, and as a general usage, they are used in the order of plate, sheet, and film in descending order of thickness. , and is used accordingly in this specification. However, such proper use has no technical meaning, so these words can be replaced as appropriate.
Furthermore, numerical values such as dimensions and material names of each member described in this specification are examples as an embodiment, and are not limited to these, and can be selected as appropriate.

(First embodiment)
FIG. 1 is a diagram showing a video display device 1 according to the first embodiment. FIG. 1(a) is a perspective view of the image display device 1, and FIG. 1(b) is a view of the image display device 1 viewed from the side (+X side, which will be described later).
The video display device 1 has a screen 10, a video source LS, and the like. The screen 10 is a reflective screen that reflects part of the image light L0 projected from the image source LS to display an image on the screen. The details of this screen 10 will be described later.

Here, in order to facilitate understanding, an XYZ orthogonal coordinate system is appropriately provided and shown in each figure shown below including FIG. In this coordinate system, the horizontal direction (horizontal direction) of the screen 10 is the X direction, the vertical direction (vertical direction) is the Y direction, and the thickness direction of the screen 10 is the Z direction. The screen of the screen 10 is parallel to the XY plane, and the thickness direction (Z direction) of the screen 10 is orthogonal to the screen of the screen 10 .
In addition, the +X direction is the direction toward the right side in the horizontal direction as viewed from the observer O1 positioned in the front direction of the image source side of the screen 10, the +Y direction is the direction toward the upper side in the vertical direction, and the back side (back side) in the thickness direction. ) toward the image source side is the +Z direction.
Furthermore, in the following description, unless otherwise specified, the up-down direction of the screen, the left-right direction of the screen, and the thickness direction refer to the up-down direction of the screen (vertical direction), the left-right direction of the screen (horizontal direction), It is the thickness direction (depth direction) and is parallel to the Y direction, X direction, and Z direction, respectively.

The image source LS is an image projection device that projects the image light L0 onto the screen 10, and is, for example, a short focus type projector. In this embodiment, the image source LS is a DLP projector using a high-pressure mercury lamp as a light source. Not limited to this, image sources using other light sources such as lasers and LEDs may be used depending on the desired optical performance, the usage environment of the image display device 1, and the like.
This image source LS is located at the center of the screen 10 in the horizontal direction when the screen (display area) of the screen 10 is viewed from the front (the direction normal to the screen surface) when the image display device 1 is in use. , and positioned below the screen of the screen 10 in the vertical direction.
In this specification, the screen surface refers to a surface in the plane direction of the screen when the screen is viewed as a whole. The screen surface of the screen 10 is parallel to the screen (XY plane) of the screen 10 .

The image source LS obliquely projects the image light L0 from a position in which the distance from the surface of the screen 10 in the depth direction (Z direction) is much shorter than that of a conventional general-purpose projector positioned in the front direction of the screen of the screen. can. Therefore, compared to conventional general-purpose projectors, the image source LS has a short projection distance to the screen 10, a large incident angle at which the projected image light L0 enters the screen 10, and a change in the incident angle (from the minimum value to The amount of change up to the maximum value) is also large.

The screen 10 reflects a part of the image light L0 projected by the image source LS toward the observer O1 positioned in the front direction on the image source side (+Z side), thereby displaying an image to the observer O1, It is a semi-transmissive reflective screen that partially transmits. The screen 10 has transparency, and the observer O1 can observe the scenery on the far side (−Z side) through the screen 10 .
The screen (display area) of the screen 10 has a substantially rectangular shape when viewed from the observer O1 side, and the long side direction is the horizontal direction of the screen when in use. The screen 10 has a diagonal screen size of about 40 to 100 inches, and a screen aspect ratio of 16:9.
In addition, the screen 10 is not limited to this, for example, the shape viewed from the observer O1 side may be another shape, the screen size may be less than 40 inches, the purpose of use, the environment of use, etc. Its size and shape can be selected as appropriate.

The screen 10 of the present embodiment is integrally joined (or partially fixed) to a support plate (not shown) via a joining layer (not shown) on the back side to maintain the flatness of the screen.
The support plate is a plate-shaped member having high rigidity, and a plate-shaped member made of resin such as acrylic resin or PC (polycarbonate) resin, glass, or the like can be used. Moreover, when the screen 10 has transparency as in the present embodiment, it is preferable that the support plate also has transparency.
In addition, the screen 10 is not limited to this, and the screen 10 may be configured such that its four sides are supported by a frame member or the like (not shown) so as to maintain its flatness.
The image display device 1 of the present embodiment can be applied to indoor partitions, image display at exhibitions and the like, show windows of stores and the like, and the support plate can be appropriately selected according to the intended use. .

FIG. 2 is a diagram showing the layer structure of the screen 10 of the first embodiment. In FIG. 2, the point A (see FIG. 1) which is the center of the screen (the geometric center of the screen) of the screen 10 is parallel to the vertical direction of the screen (Y direction) and perpendicular to the screen surface (in the Z direction). Parallel) is shown by enlarging a part of the cross section.
FIG. 3 is a diagram illustrating the first optical shape layer 12. FIG. In FIG. 3, the first optical shape layer 12 is viewed from the rear side (−Z side), and the reflective layer 13 and the like are omitted for easy understanding.
As shown in FIG. 2, the screen 10 includes a light control layer 16, a bonding layer 17a, a first base material layer 11, and a first optical shape in order from the image source side (+Z side) in the thickness direction (Z direction). It includes a layer 12, a reflective layer 13, a second optical shape layer 14, a second substrate layer 15, and the like.

The first base material layer 11 is a light-transmitting sheet-like member, and the first optically shaped layer 12 is integrally formed on the back side (−Z side) thereof. The first substrate layer 11 is a layer that serves as a substrate (base) for forming the first optically shaped layer 12 .
The first base material layer 11 is made of, for example, a polyester resin such as PET (polyethylene terephthalate) having high light transmittance, an acrylic resin, a styrene resin, an acrylic/styrene resin, a PC (polycarbonate) resin, an alicyclic polyolefin resin, or TAC. It is made of (triacetyl cellulose) resin or the like.

The first optical shape layer 12 is a layer having optical transparency formed on the back side (−Z side) of the first substrate layer 11 . A plurality of unit optical shapes (unit lenses) 121 are arranged and provided on the back side (−Z side) surface of the first optical shape layer 12 .
As shown in FIG. 3, the unit optical shape 121 is a partial shape (arc shape) of a perfect circle, and a plurality of unit optical shapes 121 are arranged concentrically around a point C located outside the screen (display area) of the screen 10. ing. That is, the first optically shaped layer 12 has a circular Fresnel lens shape with a so-called offset structure with the point C as the center (Fresnel center) on its back side.
In this embodiment, as shown in FIG. 3, when the first optically shaped layer 12 is viewed from the back side (−Z side) along the normal direction of the screen surface, the point C is the center of the screen in the horizontal direction. , and is positioned outside and below the screen, and points C and A are positioned on the same straight line extending in the Y direction.

As shown in FIG. 2, the unit optical shape 121 is parallel to the direction perpendicular to the screen surface (the Z direction) and has a substantially triangular cross-sectional shape in a cross section parallel to the arrangement direction of the unit optical shape 121. .
The unit optical shape 121 is convex on the back side (−Z side) and has a first slope (lens surface) 121a on which image light is incident and a second slope (non-lens surface) 121b that intersects with the first slope. ing. In one unit optical shape 121, the first slope 121a is positioned above (+Y side) the second slope 121b across the vertex t1.
The angle formed between the first slope 121a and a plane parallel to the screen plane (XY plane) is α. The angle between the second slope 121b and the plane parallel to the screen surface is β. The angles α and β satisfy the relationship β>α.

Further, the first slope 121a and the second slope 121b of the unit optical shape 121 are formed with fine and irregular uneven shapes. The uneven shape is formed by irregularly arranging convex shapes and concave shapes in two-dimensional directions, and the convex shapes and concave shapes are irregular in size, shape, height, and the like.

The arrangement pitch of the unit optical shapes 121 is P, and the height of the unit optical shapes 121 (dimension from the vertex t1 in the thickness direction to the bottom point t2 between the unit optical shapes 121) is h.
2 and the like, the arrangement pitch P and the angles α and β of the unit optical shapes 121 are shown to be constant in the arrangement direction of the unit optical shapes 121. As shown in FIG. However, although the unit optical shapes 121 of this embodiment actually have a constant arrangement pitch P, as the angle α moves away from the Fresnel center point C in the arrangement direction of the unit optical shapes 121 (shown in FIG. 2 It gradually (continuously) increases toward the upper side in the cross section.

It should be noted that, without being limited to this, for example, the arrangement pitch P may gradually change along the arrangement direction of the unit optical shapes 121, or the arrangement pitch P, angle α, or the like may be changed along the arrangement direction of the unit optical shapes 121. may be changed stepwise.
The angles α and β, the array pitch P, and the like are determined by the projection angle of the image light from the image source LS (the incident angle of the image light to the screen 10), the size of the pixels of the image source LS, and the screen of the screen 10. It may be set appropriately according to the size, the refractive index of each layer, and the like.

In the present embodiment, an example in which a circular Fresnel lens shape is formed on the back side (−Z side) surface of the first optically shaped layer 12 is shown, but the present invention is not limited to this, and the first optically shaped layer 12 On the back side surface, unit optical shapes 121 may extend in the horizontal direction (X direction) of the screen, and linear Fresnel lens shapes arranged in the vertical direction (Y direction) of the screen may be formed. Further, a plurality of unit prisms having a substantially triangular cross-sectional shape and extending in the horizontal direction (X direction) of the screen as a ridgeline direction may be arranged in the vertical direction (Y direction) of the screen.

The first optically shaped layer 12 is made of UV curable resin such as urethane acrylate, polyester acrylate, epoxy acrylate, polyether acrylate, polythiol, butadiene acrylate, etc., having high light transmittance.
In the present embodiment, as the resin constituting the first optically shaped layer 12, an ultraviolet curable resin will be described as an example. You may form with resin.

The reflective layer 13 is a semi-transmissive reflective layer that partially reflects and partially transmits incident light, and is a so-called half mirror. The reflective layer 13 is formed on the unit optical shape 121, that is, on the first slope 121a and the second slope 121b. The reflective layer 13 is provided between and adjacent to the first optically shaped layer 12 and the second optically shaped layer 14 .
The reflective layer 13 has a surface on the image source side (surface on the side of the first optically shaped layer 12) and a surface on the back side (surface on the side of the second optically shaped layer 14) having fine and irregular uneven shapes. It is a face. This is because, as described above, the first slope 121a and the second slope 121b are formed with fine uneven shapes, and the reflective layer 13 is formed following the fine uneven shapes. This is because the thickness of the reflective layer 13 is sufficiently thinner than the unevenness of the fine unevenness.
The reflective layer 13 has the function of diffusely reflecting part of the incident light through fine and irregular irregularities and transmitting at least part of the other non-reflected light without diffusion.

The reflectance and transmittance of the reflective layer 13 can be appropriately set according to the desired optical performance. From the viewpoint of good reflection of image light and good transmission of light other than image light (for example, light from the outside such as sunlight), the reflectance and transmittance of the reflective layer 13 are set to 30 to 30. Desirably, the reflectance is about 80% and the reflectance is about 5 to 60%.

The reflective layer 13 is made of a highly light-reflective metal such as aluminum, silver, nickel, or chromium. In addition, the reflective layer 13 is not limited to this, and is formed by, for example, sputtering a metal with high light reflectivity as described above, transferring a metal foil, or applying a paint containing a thin metal film. may be
The reflective layer 13 may be formed by vapor deposition of a dielectric multilayer film or a dielectric single-layer film that has high transparency, low light absorption loss, and high reflectance.
The reflective layer 13 of this embodiment is formed by evaporating chromium, and the reflective layer 13 alone has a reflectance of about 5% and a transmittance of about 50%.
In this embodiment, an example in which the reflective layer 13 is formed on the first slope 121a and the second slope 121b of the unit optical shape 121 is shown. It is good also as a form formed in a part.

The second optical shape layer 14 is a layer having optical transparency provided adjacent to the back side (−Z side) of the reflective layer 13 . The second optical shape layer 14 is filled so as to sufficiently fill the valleys between adjacent unit optical shapes 121, and the rear surface of the second optical shape layer 14 is flat parallel to the screen surface. It has a planar shape.
Such a second optical shape layer 14 can improve the light transmittance of the screen 10 and protect the reflective layer 13 . Also, by providing the second optically shaped layer 14, the second substrate layer 15 and the like are easily laminated.

From the viewpoint of improving the transparency of the screen 10, it is preferable that the refractive index of the second optically shaped layer 14 is equal to that of the first optically shaped layer 12, or has a small refractive index difference to the extent that it can be regarded as being equal. . Also, the second optically shaped layer 14 may be formed using the same resin as the first optically shaped layer 12, or may be formed using a different resin.
The second optically shaped layer 14 of the present embodiment is made of the same UV curable resin as the first optically shaped layer 12 and has the same refractive index as that of the first optically shaped layer 12 .

The second base material layer 15 is a sheet-like member having optical transparency, and is integrally laminated on the back side of the second optical shape layer 14 . Like the first base layer 11, the second base layer 15 includes, for example, polyester resin such as PET (polyethylene terephthalate) having high light transmittance, acrylic resin, styrene resin, acrylic/styrene resin, PC ( Polycarbonate) resin, alicyclic polyolefin resin, TAC (triacetyl cellulose) resin, or the like.
In this embodiment, the second base material layer 15 is made of the same material as the first base material layer 11 .

The bonding layer 17a is a layer having a function of integrally bonding the light control layer 16 and the first base layer 11 together. For the bonding layer 17a, an adhesive material, an adhesive material, or the like having high optical transparency can be used.
The light control layer 16 is a layer located closer to the image source side (+Z side) than the first base material layer 11 in the thickness direction, and diffuses and transmits light incident from a specific angle range, It is a layer that has the function of transmitting light incident from an area without diffusing it. The light control layer 16 is integrally provided on the image source side (+Z side) of the first base material layer 11 via a bonding layer 17a.
4A and 4B are diagrams for explaining the light control action of the light control layer 16. FIG. FIG. 4 shows a cross section of the light control layer 16 parallel to the vertical direction of the screen (Y direction) and the thickness direction (Z direction). In FIG. 4, the image source side (+Z side) surface and the back side (−Z side) surface of the light control layer 16 are parallel to the screen surface (XY plane), and the dashed straight line H is It is a straight line orthogonal to the surface of the light control layer 16 on the image source side and the surface on the back side.

In the cross section shown in FIG. 4, the light control layer 16 diffuses light incident from the air on the image source side (+Z side) at an incident angle within the first incident angle range R1 to the rear side (−Z side). and transmits the light incident at an incident angle within the second incident angle range R2, which is an incident angle other than the first incident angle range R1, to the rear side without diffusing.
Further, in the cross section shown in FIG. 4, the light control layer 16 diffuses the incident light from the air on the back side (−Z side) at an incident angle within the third incident angle range R3 to the image source side (+Z side). side), and has a function of transmitting the light incident at an incident angle within the fourth incident angle range R4, which is an incident angle other than the third incident angle range R3, to the image source side without diffusing. .

The first incident angle range R1 includes the main incident angle range of the image light L0 projected from the image source LS and incident on the screen 10 (light control layer 16).
The first incident angle range R1 is a range of 25° or more and 55° or less downward (−Y side) with respect to the straight line H on the image source side (+Z side). At this time, the light control layer 16 diffuses light incident on an arbitrary point on the surface on the image source side from the lower side in the vertical direction of the screen at an incident angle of 25° or more and 55° or less to the rear side ( −Z side).
Also, the second incident angle range R2 is an angle other than the first incident angle range R1 on the image source side of the light control layer 16 .

The third incident angle range R3 is a range of 25° or more and 55° or less upward (+Y side) with respect to the straight line H on the rear side (−Z side). At this time, the light control layer 16 diffuses light incident on an arbitrary point on the back side surface from the upper side in the vertical direction of the screen at an incident angle of 25° or more and 55° or less to the image source side (+Z side).
Further, the fourth incident angle range R4 is an angle other than the third incident angle range R3 on the rear surface side of the light control layer 16 .

Therefore, the light control layer 16 diffuses and transmits light incident at an incident angle of 25° or more and 55° or less from the bottom side of the screen in the vertical direction at any point on the surface on the image source side, and diffuses and transmits light from other angle ranges. Transmits incident light without diffusing it. In addition, the light control layer 16 diffuses and transmits light that is incident from the upper side in the vertical direction of the screen at an arbitrary point on the back side surface at an incident angle of 25° or more and 55° or less, and is incident from other angle ranges. Transmits light without diffusing it.

The haze value (diffuse transmittance) of the light incident on the light control layer 16 from the image source side at an incident angle within the first incident angle range R1 and emitted to the rear side is preferably 80% or more. It is preferable that the haze value of the light incident on the light control layer 16 from the back side at an incident angle within the third incident angle range R3 and emitted to the image source side be the same.
The haze value is expressed as a ratio of diffuse transmittance to total light transmittance, and means the diffusion rate of light in transmitted light. The haze value of the light control layer 16 can be measured by a haze meter (HM-150 manufactured by Murakami Color Research Laboratory).

For incident light within the ranges of the first incident angle range R1 and the third incident angle range R3, since the first incident angle range R1 and the third incident angle range R3 of the present embodiment are 25° or more and 55° or less, Assuming that the assumed incident angle is 40°, the transmittance when light is incident at this angle is defined as the total light transmittance. On the other hand, the diffuse transmittance is defined as the ratio of the light emitted with a spread of 2.5° or more.

On the other hand, the haze value (diffuse transmittance) of the light incident on the light control layer 16 from the image source side at an incident angle within the second incident angle range R2, especially the light incident at an incident angle of 0° and emitted to the back side is preferably low, ideally 0%. It is preferable that the haze value of light incident on the light control layer 16 at an incident angle within the fourth incident angle range R4 is also the same.

As such a light control layer 16, a plurality of transparent resin layers having different refractive indices are laminated in a predetermined thickness in a predetermined direction, and the irradiation direction of ultraviolet rays during curing of each layer is changed. A view control film (for example, view control film Y-2555 manufactured by Lintec Corporation) is suitable.

As described above, the screen 10 of the present embodiment does not include a light diffusion layer containing a diffusion material such as particles that diffuse light, and the light control layer 16 has a specific angle range (first incident angle). Only the light incident at the incident angles within the angle range R1 and the third incident angle range R3) is diffused, and is diffusely reflected by the minute irregularities on the surface of the reflective layer 13 .
In the present embodiment, the combined thickness of the bonding layer 17a and the first base layer 11, that is, the image source side (+Z side) surface of the first optical shape layer 12 in the thickness direction (Z direction) of the screen 10 , and the rear surface (−Z side) of the light control layer 16 is preferably 0.5 mm or less. When the distance D1 is 0.5 mm or less, blurring of the image can be suppressed, and clarity of the image can be improved. Therefore, the distance D1 is preferably within the above range.

FIG. 5 is a diagram showing an example of image light and external light incident on the screen 10 of the first embodiment. FIG. 5 shows an enlarged part of a cross section similar to the cross section of the screen 10 shown in FIG. Also, in FIG. 5, for ease of understanding, it is assumed that there is no refractive index difference between the layers.
The image light L11 projected from the image source LS positioned below the screen 10 is incident on the light control layer 16 at an incident angle within the first incident angle range R1 and is diffused to pass through the bonding layer 17a and the first base material layer. 11 and enters the first optical shaped layer 12 . The image light L12, which is a part of the image light L11, is diffusely reflected by the reflection layer 13 of the first slope 121a of the unit optical shape 121 and emitted to the image source side (+Z side). At this time, in the cross section of the screen 10 shown in FIG. 5, the image light L12 is incident on the light control layer 16 at an incident angle in the fourth incident angle range R4 (in particular, an incident angle of 0° and near 0°) from the rear side. Since the light is incident at a corresponding angle, it is emitted to the image source side without being diffused by the light control layer 16 and reaches the observer O1 side.

Therefore, the image light L12 enters the light control layer 16 within the first incident angle range R1 and is diffusely reflected by the reflective layer 13 . Thereby, the image light L12 is preferably diffused, and the screen 10 can display an image with a sufficient viewing angle.
Further, the image light L12 is diffused by the light control layer 16 when incident on the screen 10 and is diffusely reflected by the reflection layer 13, so that it is diffused twice at different positions in the thickness direction of the screen 10. FIG. As a result, the screen 10 can reduce image glare (speckle) and suppress image blurring (decrease in resolution) due to excessive diffusion.

Note that the image light L11 is projected from below the screen 10, and the angle β (see FIG. 2) is larger than the incident angle of the image light L11 at each point in the vertical direction (Y direction) of the screen 10. , the image light L11 does not directly enter the second slope 121b, and the second slope 121b does not contribute to the reflection of the image light.
A part of the image light L13 of the image light L11 is transmitted through the reflection layer 13 toward the back side, and is transmitted through the second optical shape layer 14 and emitted upward toward the back side. In addition, when such image light L13 reaches the ceiling on the back side, it causes reflection of the image on the ceiling. However, in the screen 10 of this embodiment, the image light L13 is diffused by the light control layer 16, and even when the image light L13 reaches the ceiling, a clear image is not reflected on the ceiling.

Next, external light such as sunlight and illumination light other than image light entering the screen 10 from the rear side (−Z side) or the image source side (+Z side) will be described.
External light G11 and G12, which are the majority of the external light with a small incident angle to the screen 10, enter the screen 10, pass through the reflective layer 13, and exit toward the rear side and the image source side, respectively. The screen 10 does not include a layer (light diffusion layer) containing a diffusion material such as particles that diffuse light, and the external light G11 enters the light control layer 16 at a second incident angle from the image source side. The external light G12 enters the light control layer 16 at an incident angle within the range R2 from the back side at an incident angle corresponding to an angle within the fourth incident angle range R4. Therefore, the external lights G11 and G12 are transmitted through the screen 10 without being diffused by the light control layer 16 .
Therefore, when the observers O1 and O2 observe the scenery on the other side of the screen 10 through the screen 10, they can observe the scenery on the other side of the screen 10 without blurring or whitening. 10 can exhibit high transparency.

Of the external light G13 incident on the screen 10 from above the image source side, part of the external light (not shown) is reflected by the surface of the screen 10, travels downward, and reaches the observers O1 and O2. does not reach. In addition, since the external light G13 is incident on the light control layer 16 from the image source side at an incident angle within the second incident angle range R2, it passes through the light control layer 16 without being diffused and passes through the screen 10. Go to the back side. Part of the external light G14 of the external light G13 is reflected by the reflective layer 13, travels downward on the image source side of the screen 10, is emitted downward on the image source side of the screen 10, or The light is totally reflected by the surface on the source side, travels downward inside the screen 10 again, and is attenuated. A part of the external light G15 of the external light G13 is transmitted through the reflective layer 13 and emitted downward on the back side of the screen 10, and does not reach the observers O1 and O2.

Part of the external light G16 incident on the screen 10 from above the rear side (not shown) is reflected by the surface of the screen 10, travels downward, and does not reach the observers O1 and O2. Part of the external light G17 out of the external light G16 enters the screen 10 and is diffusely reflected by the reflective layer 13, but is emitted upward on the rear side, so that it does not reach the observers O1 and O2. Part of the external light G18 of the external light G16 is transmitted through the reflective layer 13 and emitted downward on the image source side. This external light G18 may be diffused by the light control layer 16 depending on the angle at which it is incident on the light control layer 16 from the rear side, but is emitted downward from the screen 10 and does not reach the observers O1 and O2. , the effect of diffusion on the image contrast is small.
Therefore, the screen 10 can suppress deterioration of image contrast due to external light incident from the upper side of the image source side or the upper side of the back side.

In a conventional reflective screen provided with a light diffusing layer containing a diffusing material such as particles for diffusing light at a position corresponding to the light control layer 16 of the screen 10 of the present embodiment, image light passes through the reflective layer. In addition to the diffuse reflection, the light is diffused by the light diffusion layer twice, before and after being reflected by the reflection layer. Therefore, the image light is excessively diffused, resulting in image blurring (decrease in resolution).
In contrast, according to the present embodiment, the image light is not diffused after being diffusely reflected by the reflective layer 13, so that a high-resolution image can be displayed.

In addition, in the conventional reflective screen provided with such a light diffusion layer, the light diffusion layer also diffuses unnecessary external light, so that the observers O1 and O2 observe the scenery on the other side of the screen 10 through the screen 10. In this case, the scenery on the other side of the screen 10 is blurred or whitened, and the transparency of the screen is lowered and the contrast of the image is lowered.
On the other hand, according to the present embodiment, the screen 10 does not have such a light diffusion layer, and most of the external light is transmitted through the screen without being diffused, or diffused. Also, as shown in FIG. 5, the light exits outside the visible range of the observers O1 and O2. Therefore, when the observers O1 and O2 observe the scenery on the other side of the screen 10 through the screen 10, the scenery on the other side of the screen 10 is neither blurred nor blurred, and the transparency of the screen can be maintained. In addition, it is possible to greatly suppress deterioration in image contrast due to diffusion of external light.

As described above, according to the present embodiment, it is possible to suppress the glare of the image, and suppress the blurring of the image (decrease in resolution) to display a clear image.
Moreover, according to the present embodiment, unnecessary external light is not diffused and reaches the observer, so that a high-contrast image can be displayed and the screen can be made highly transparent.
Furthermore, according to the present embodiment, it is possible to suppress reflection of an image on the ceiling or the like caused by the image light transmitted through the reflective layer 13 .

(Evaluation of image glare, etc.)
Here, a screen corresponding to an example of the screen 10 of the present embodiment and a screen of a comparative example were prepared, and the effect of reducing image glare, image clarity, and the like were evaluated.
The screens of Example 1 and Comparative Examples 1 and 2 each have a screen size of 40 inches.
The light control layer 16 of Example 1 is a view control film Y-2555 manufactured by Lintec Corporation.

The screen of Comparative Example 1 includes a first substrate layer 11, a first optically shaped layer 12, a reflective layer 13, a second optically shaped layer 14, and a second substrate layer 15 similar to the screen 10 of the embodiment. However, the bonding layer 17a and the light control layer 16 are not provided.
Compared to the screen of Comparative Example 1, the screen of Comparative Example 2 corresponds to a mode in which a light diffusion layer, not the light control layer 16, is laminated on the image source side of the first base material layer 11 via the bonding layer 17a. . This light diffusion layer is a layer made of resin containing particles that diffuse light, and has the characteristic of diffusing light regardless of the incident angle of light.
Therefore, the screen of Example 1 and the screens of Comparative Examples 1 and 2 have the same configuration from the first substrate layer 11 to the second substrate layer 15, but the presence or absence of the light control layer 16 is different. It's becoming

The details of the layers common to the screens of Example 1 and Comparative Examples 1 and 2 are as follows.
The first base material layer 11 is made of polycarbonate resin with a refractive index of 1.59 and has a thickness of 0.075 mm.
The first optical shape layer 12 is made of an ultraviolet curable resin (urethane acrylate) with a refractive index of 1.51, and its thickness changes in the arrangement direction of the unit optical shapes 121 depending on the height h of the unit optical shapes 121. However, it is 0.01 mm at the center of the lower edge of the screen and 0.14 mm at the center of the upper edge of the screen.

The reflective layer 13 is made of chromium and has a thickness of several nanometers.
The second optical shape layer 14 is made of an ultraviolet curable resin (urethane acrylate) with a refractive index of 1.51, and its thickness changes in the arrangement direction of the unit optical shapes 121 depending on the height h of the unit optical shapes 121. However, it is 0.14 mm at the center of the lower edge of the screen and 0.01 mm at the center of the upper edge of the screen.
The second base material layer 15 is made of polycarbonate resin with a refractive index of 1.59 and has a thickness of 0.075 mm.

Regarding the screens of Example 1 and Comparative Examples 1 and 2, the speckle contrast, peak gain, peak brightness, total light transmittance, and haze value were each measured, and visual evaluation was performed to determine the glare and clarity of the image, the screen The transparency of the image, the presence or absence of reflection of images on the ceiling (so-called ceiling ghost), etc. were evaluated.
The total light transmittance and the haze value were also measured for the light control layer 16 of the screen of Example 1 and the light diffusion layer of Comparative Example 2, respectively.
Methods for measuring speckle contrast, peak gain, peak luminance, total light transmittance, haze value, etc. are described below.

FIG. 6 is a diagram showing the positions of each screen, image source LS, luminance meter K, observer O3, and the like during measurement of peak luminance and the like and visual evaluation.
FIG. 6A shows the positions of each screen, the image source LS, the luminance meter K, and the observer O3 when measuring the peak luminance and the like as viewed from the side (+X side). FIG. 6B shows the positions of each screen, the image source LS, the luminance meter K, and the observer O3 when measuring the peak luminance and the like as viewed from above (+Y side).
In FIG. 6, the luminance meter K and the observer O3 are shown shifted in the Z direction for easy understanding.

The speckle contrast corresponds to a value obtained by dividing the standard deviation σ of the surface light intensity distribution in a predetermined area by the average value I of the surface light intensity distribution in the predetermined area when the screen is irradiated with monochromatic light. The smaller the value, the smaller the speckle is evaluated. According to the speckle contrast guidelines by NEDO (New Energy and Industrial Technology Development Organization), when the speckle contrast is 0.05 or more for red light and green light, and 0.08 or more for blue light, spec It is said that the le is easily recognized by the human eye.
Here, the speckle contrast is measured from the image source LS using a measuring machine (Dr. SPECKLE/SM01VS09 manufactured by Oxide Co., Ltd.) in accordance with the international standard IEC 62906-5-2/62906-5-4. Measurements were taken in a state where a green screen was projected on the entire surface of the screens of Example 1 and Comparative Examples 1 and 2. FIG. The measurement was performed at a pupil angle of 1 degree with the above-described measuring machine from a position 800 mm from point A, which is the screen center of each screen, toward the image source (+Z side). The speckle contrast of this green light is hereinafter referred to as speckle contrast Cs(G).

A method of calculating the peak gain is as follows.
First, the screens of Example 1 and Comparative Examples 1 and 2 were placed in a darkroom environment, and a white screen was projected on the entire surface by an image source LS (PJWX-4152N manufactured by Ricoh Co., Ltd.), as shown in FIG. The luminance at point A, which is the center of the screen, was measured from a position 1 m away from point A in the +Z direction using a luminance meter K (BM-9 manufactured by Topcon Corporation). The measurement with the luminance meter K was performed by finely adjusting the position of the luminance meter K, setting the position where the highest luminance was obtained, and measuring the maximum luminance Lmax (cd/m ² ). The installation position of the image source LS is a position according to the instruction manual of the image source LS used, and the incident angle θ of the image light at the point A in the cross section shown in FIG. 6A is θ= 50°.
Next, an illuminance meter (IM-600 manufactured by Topcon Corporation) was used to measure the illuminance Iw (lx) at the point A, which is the center of the screen, when the white screen was projected.
From the obtained values, the gain G was calculated using the following formula.
G=Lmax×π/Iw
The obtained gain G corresponds to the peak gain.
Note that the peak luminance is the maximum luminance obtained by the above measurement.

Regarding the total light transmittance and the haze value, a 10 cm square having sides parallel to the screen horizontal direction and the screen vertical direction centering on the point A which is the center of the screen of the screen of Example 1 and Comparative Examples 1 and 2 A member is cut out as a sample of each screen, and the total light transmittance and haze value at point A are measured using this sample.
The total light transmittance is the transmittance of light incident at an incident angle of 0°. The total light transmittance was measured using a screen sample according to JIS K7316 with a haze meter (HM-150 manufactured by Murakami Color Laboratory Co., Ltd.). During measurement, the sample was placed so that the image source side (observer side) of the screen in use was on the sensor side of the haze meter.

As described above, the haze value is the ratio of the diffuse transmittance to the total light transmittance for light incident at an incident angle of 0°. Measured with HM-150 manufactured by Shiki Kenkyusho Co., Ltd. During measurement, the sample was placed so that the image source side (viewer side) of the screen in use was on the sensor side of the haze meter.
The light control layer 16 of the screen of Example 1 and the light diffusion layer of the screen of Comparative Example 2 were also measured for total light transmittance and haze value using the above-described methods.

Furthermore, the screens of Example 1 and Comparative Examples 1 and 2 were visually evaluated for the presence or absence of image glare, the clarity of the image, the transparency of the screen, and the presence or absence of reflection of the image on the ceiling.
With respect to the glare of the image, in a darkroom environment with respect to the screens of Example 1 and Comparative Examples 1 and 2, in a state where a white screen is projected from the image source LS, from the point A which is the center of the screen of each screen Observer O3 observed and evaluated the central portion of the screen from a position 1 m away from the image source side (+Z side).

Regarding the clarity of the images, the screens of Example 1 and Comparative Examples 1 and 2 were subjected to projection of a still image (white characters on a black background) from the image source LS in a darkroom environment. An observer O3 observed and evaluated the central portion of the screen from a position 1 m away from the central point A on the image source side (+Z side).
Regarding the transparency of the screen, in a bright room environment (illuminance of 700 lx at point A, which is the center of the screen), without projection of image light from the image source, from point A, which is the center of the screen of each screen Observer O3 observed and evaluated the central portion of the screen from a position 1 m away from the image source side (+Z side).

The presence or absence of the reflection of the image on the ceiling (so-called ceiling ghost) was determined in a darkroom environment with respect to the screens of Example 1 and Comparative Examples 1 and 2 by obtaining a still image (white characters on a black background) from the image source LS. is projected, the image light transmitted through each screen reaches the ceiling located 1.5 m above (+Y side) on the back side (-Z side) of each screen and observes the displayed image. and evaluated. At this time, since the space between each screen and the ceiling is an open space, the observer O3 is positioned 1 m from the point A, which is the center of the screen of each screen, toward the image source side (+Z side). The ceiling was observed and evaluated.
In each evaluation, there were three observers O3, and the evaluation results were taken as the average.

Table 1 shows the evaluation results of the screens of Example 1 and Comparative Examples 1 and 2. Table 1 also shows the transmittance and haze of the light control layer 16 and the light diffusion layer used in Example and Comparative Example 2.
In Table 1, glare is indicated by ⊙ when the glare of the image is not visually recognized, indicated by ○ when the glare is within the allowable range but is slightly visible, and is visually uncomfortable. It was indicated by x as being unacceptable.
In addition, in Table 1, the clarity of the image is indicated by ◎ when a clear image without image blur is visually recognized, and by ◯ when there is a little image blur but is sufficiently clear. , and x indicates that the image is blurred and is not suitable for use.

In Table 1, the transparency is indicated by ⊙ when the transparency is high, and when the transparency is slightly inferior to the good but has sufficient transparency in use, it is indicated by ◯. Poor transparency, such as the other side looking white and turbid, was indicated by x as being unsatisfactory.
In Table 1, the presence or absence of reflection of the image on the ceiling (so-called ceiling ghost) is indicated by ◎ when the image pattern projected on the ceiling cannot be recognized by the image light transmitted through the screen. When the image pattern was recognizable but unclear compared to , it was indicated by ◯, and when the image pattern was clearly recognizable, it was indicated by ×.

The overall evaluation is based on the speckle contrast Cs (G), peak gain, peak luminance, transmittance, glare and clarity of images by visual evaluation, screen transparency, and image quality on the ceiling for each screen. This is an evaluation that takes into consideration all reflections, etc., and if the image glare is reduced, the image is clear, the transparency is sufficient, and the reflection of the image on the ceiling is not recognizable, it is evaluated as good. Those that are inferior to good but usable are indicated by ◯, and those that are not suitable for use are indicated by x.

As shown in Table 1, the screen of Comparative Example 1, which does not have the light control layer 16 on the image source side of the first base material layer 11, has a high peak gain and brightness, and the brightness of the image is sufficient. It is also clear and has good transparency, but the image glare occurs, which is not preferable. Moreover, in the screen of Comparative Example 1, the reflection of the image on the ceiling on the back side of the screen is visually recognized, which is not preferable.
In addition, in the screen of Comparative Example 2, which has a light diffusion layer on the image source side of the first base material layer 11, the speckle contrast Cs (G) is the smallest, and even in visual evaluation, there is no glare in the image. effectively suppressed. However, in the screen of Comparative Example 2, the peak gain and luminance decreased, resulting in a darker image. In addition, the image was unclear even in visual evaluation (large image blur), and the transparency was greatly reduced. . This is probably because the light diffusion layer diffuses light irrespective of the incident angle of the light, so external light such as illumination light is also diffused. Furthermore, in the screen of Comparative Example 2, the reflection of the image on the ceiling on the back side of the screen was visually recognized.

On the other hand, the screen of Example 1 also has a speckle contrast Cs (G) of less than 0.05, and the glare of the image can be sufficiently reduced even by visual evaluation. In addition, sufficient peak gain and peak luminance were secured, and in visual evaluation, the image was clear and sufficiently transparent, and no reflection of the image on the ceiling on the back side of the screen was visually recognized.

As described above, according to the present embodiment, it is possible to provide the screen 10 and the image display device 1 capable of displaying a clear image and reducing the glare of the image.
Further, according to the present embodiment, the transparency of the screen 10 can be sufficiently ensured while having the above effects. Furthermore, according to the present embodiment, it is possible to suppress reflection of the image on the ceiling on the back side of the screen.

(Second embodiment)
FIG. 7 is a diagram showing the layer structure of the screen 20 of the second embodiment.
In FIG. 7, as in FIG. 2 of the first embodiment described above, a point (a point corresponding to point A shown in FIG. 1) that is the center of the screen (the geometric center of the screen) of the screen 20 is passed through, and A part of the cross section parallel to the direction (Y direction) and orthogonal to the screen surface (parallel to the Z direction) is shown enlarged.
The screen 20 of the second embodiment has a thicker portion on the back side than the reflective layer 13, and the light control layer 30 is provided on the back side of the second base material layer 25 via the bonding layer 17c. The screen 10 is different from the screen 10 shown in the above-described first embodiment except for the points, but otherwise has the same form as the above-described first embodiment. Therefore, in the following description, portions that perform the same functions as those of the first embodiment described above are denoted by the same reference numerals or the same reference numerals at the end thereof, and overlapping explanations are omitted as appropriate.

As shown in FIG. 7, the screen 20 of the second embodiment includes the light control layer 16, the bonding layer 17a, the first substrate, and the image source side (+Z side) in order in the thickness direction (Z direction) of the screen 20. A material layer 11 , a first optically shaped layer 12 , a reflective layer 13 , a second optically shaped layer 14 , a second substrate layer 25 , a bonding layer 17 c and a light control layer 30 are provided. This screen 20 can be applied to the video display device 1 in place of the screen 10 of the first embodiment.
Also in the screen 20 of the present embodiment, the combined thickness of the bonding layer 17a and the first base layer 11, that is, the image source side (+Z side) of the first optical shape layer 12 in the thickness direction (Z direction) of the screen 10 ) and the rear surface side (−Z side) surface of the light control layer 16 is preferably 0.5 mm or less from the viewpoint of reducing image blur.

The second base material layer 25 of the present embodiment is thicker than the second base material layer 15 of the first embodiment, and has sufficient rigidity to maintain the flatness of the screen surface of the screen 20. . Therefore, the screen 20 can sufficiently maintain flatness as the screen 20 without being joined to a support plate or the like (not shown) shown in the first embodiment. It should be noted that the support plate as described above may be joined to the back side of the screen 20 via a joining layer (not shown) to further improve the flatness of the screen surface.
A plate-shaped member made of highly transparent acrylic resin, polycarbonate resin, glass, or the like is preferably used for the second base material layer 25 . The thickness of the second base material layer 25 is preferably about 3 to 8 mm, and can be appropriately selected according to the screen size of the screen 20 and the like.

In addition, since the screen 20 of the present embodiment is provided with the second base material layer 25 as described above, the screen 20 of the present embodiment can The distance D2 from the back side (−Z side) surface of the second optical shape layer 14 is from the back side (−Z side) surface of the light control layer 16 to the image source side (+Z side) of the first optical shape layer 12. ) is greater than the distance D1 to the surface of That is, the shortest distance from the image source side (+Z side) surface of the light control layer 30 to the reflective layer 13 is longer than the shortest distance from the back side (−Z side) surface of the light control layer 16 to the reflective layer 13. big.
As a result, the distance D1 can be reduced while ensuring a thickness that allows the flatness of the screen 20 to be maintained. Therefore, since the distance from the light control layer 16 to the reflective layer 13 can also be reduced, the image light incident on the light control layer 16 at an incident angle within the first incident angle range R1 is diffused by the light control layer 16 to form the screen 20. By advancing while expanding inside, it is possible to reduce image blur such as double images caused by the position reflected by the reflective layer 13 being separated.

If the screen has the second base material layer 25 like the screen of the present embodiment and does not have the light control layer 30 described later, the thickness of the second base material layer 25 is greater than that of the reflective layer 13. Thickness on the back side increases. Therefore, in such a screen, the image light incident on the light control layer 16 at an angle within the first incident angle range R1 is diffused, and spreads widely as it travels toward the rear side within the screen. A portion of the image light is totally reflected at the interface with the air on the back side of the screen, travels toward the image source, and emerges from the screen toward the observer. Decrease in quality.
Also, part of the image light that has passed through the reflective layer 13 causes reflection of the image on the ceiling, as described above.
In order to improve these, the screen 20 of this embodiment has the light control layer 30 on the back side (−Z side) of the second base material layer 25 .

The joining layer 17c is a layer having a function of joining the second base material layer 25 and the light control layer 30 together. For the bonding layer 17c, similarly to the bonding layer 17a described above, an adhesive material, a pressure-sensitive adhesive, or the like having high optical transparency can be used.

The light control layer 30 is a light absorption layer that partially absorbs and partially transmits incident light. The light modulating layer 30 of the present embodiment is a film that can control the amount of transmitted light by changing the applied voltage, and absorbs at least part of the incident light to reduce the amount of transmitted light, i.e. , has the function of controlling the transmittance of light.
The light control layer 30 of this embodiment is a guest-host type liquid crystal cell using a dichroic dye, and is a liquid crystal cell that changes the amount of transmitted light by an electric field applied to the liquid crystal. The light control layer 30 is configured by sandwiching a liquid crystal layer 36 between a film-like second laminate 30B for liquid crystal and a first laminate 30A for liquid crystal.

The second laminate for liquid crystal 30B is formed by laminating a transparent electrode 32B, an alignment layer 33B, and bead spacers 34 on a substrate 31B.
The first laminate for liquid crystal 30A is formed by laminating a transparent electrode 32A and an alignment layer 33A on a substrate 31A.
The light control layer 30 is formed of a liquid crystal material of a guest-host liquid crystal composition provided in the liquid crystal layer 36 by driving the

transparent electrodes

32A and 32B provided in the first liquid crystal laminate 30A and the second liquid crystal laminate 30B. orientation is changed, thereby changing the amount of transmitted light.

Various transparent resin films can be applied to the

substrates

31A and 31B, but a transparent resin film having a small optical anisotropy and a transmittance of 80% or more in the visible wavelength range (380 to 800 nm) is used. should be applied.
Materials for the transparent resin film include, for example, acetylcellulose resins such as triacetylcellulose (TAC), polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene (PE), and polypropylene (PP). , polystyrene, polymethylpentene, EVA and other polyolefin resins, polyvinyl chloride, polyvinylidene chloride and other vinyl resins, acrylic resins, polyurethane resins, polysulfone (PEF), polyethersulfone (PES), polycarbonate ( PC), polysulfone, polyether (PE), polyetherketone (PEK), (meth)acrylonitrile, cycloolefin polymer (COP), cycloolefin copolymer and the like.
Resins such as polycarbonate (PC), cycloolefin polymer (COP), and polyethylene terephthalate (PET) are particularly preferable as materials for the transparent resin film.
Transparent resin films of various thicknesses can be applied to the

substrates

31A and 31B.

The transparent electrode (first electrode) 32A and the transparent electrode (second electrode) 32B are composed of a transparent conductive film laminated on a transparent resin film.
As the transparent conductive film, various transparent electrode materials that are applied to this type of transparent resin film can be applied, and an oxide-based transparent metal thin film having a total light transmittance of 50% or more can be used. . Examples include tin oxide, indium oxide, and zinc oxide.

Tin oxide (SnO ₂ )-based materials include Nesa (tin oxide SnO ₂ ), ATO (Antimony Tin Oxide), and fluorine-doped tin oxide.
Indium oxide (In ₂ O ₃ )-based materials include indium oxide, ITO (Indium Tin Oxide), and IZO (Indium Zinc Oxide).
Zinc oxide (ZnO) systems include zinc oxide, AZO (aluminum-doped zinc oxide), and gallium-doped zinc oxide.
In this embodiment, the transparent conductive film is formed of ITO (Indium Tin oxide).

In this embodiment, spherical bead spacers 34 are used as spacers. The bead spacers 34 are provided to define the thickness (cell gap) of the liquid crystal layer 36 excluding the outer peripheral portion. The bead spacers 34 can be widely applied with inorganic materials such as silica, organic materials, core-shell structures combining these materials, and the like. Further, the shape of the bead spacer 34 may be a rod shape such as a columnar shape or a prismatic shape, in addition to the spherical configuration described above.
However, the spacers that define the thickness of the liquid crystal layer 36 are not limited to the bead spacers 34. For example, a photoresist is applied to the

substrate

31A or 31B, exposed to light, and developed to form a cylindrical shape. can be made to
In the above description, an example in which the spacers are provided in the second liquid crystal laminate 30B is shown, but the present invention is not limited to this, and the first liquid crystal laminate 30A and the second liquid crystal laminate 30B , or may be provided only in the first liquid crystal laminate 30A.

The alignment layers 33A and 33B are films for aligning liquid crystal molecules in a certain direction. For example, the alignment layers 33A and 33B may be in the state of the alignment films themselves, or may be manufactured by subjecting them to alignment treatment such as photo-alignment treatment or rubbing treatment, or they may be produced by shaping fine line-shaped irregularities. may be used to produce an alignment layer. Note that the method of manufacturing the alignment layers 33A and 33B is not limited to the method described above, and different methods may be used as appropriate.
In this embodiment, rubbing polyimide resin layers are used as the alignment layers 33A and 33B.
Moreover, in the present embodiment, the light modulating layer 30 has the orientation layers 33A and 33B. However, the present invention is not limited to this, and the orientation layers 33A and 33B may not be provided.

A guest-host liquid crystal composition using a dichroic dye composition can be widely applied to the liquid crystal layer (liquid crystal material as a light modulating material) 36 . The guest-host liquid crystal composition contains a chiral agent, and the liquid crystal material is horizontally aligned (aligned parallel to the plane direction of the light control layer 30 and aligned in a direction orthogonal to the thickness direction of the liquid crystal layer 36). In this case, the liquid crystal layer 36 may be oriented in a spiral shape in the thickness direction. In addition, in the dimming layer 30 , a sealing material 35 is arranged so as to surround the liquid crystal layer 36 . The sealing material 35 holds the first liquid crystal laminate 30A and the second liquid crystal laminate 30B together, thereby preventing leakage of the liquid crystal material. For the sealing material 35, for example, a thermosetting resin such as an epoxy resin or an acrylic resin, an ultraviolet curable resin, or the like can be applied.

The light-modulating layer 30 is configured by horizontally aligning the alignment layers 33B and 33A with an alignment regulating force related to pretilt in a certain direction so that the alignment of the guest-host liquid crystal composition when light is shielded is formed when no electric field is applied. , which is normally dark.
Here, normally dark means a structure in which the transmittance is minimized when no voltage is applied to the liquid crystal, resulting in a black screen. Also, normally clear is a structure in which the transmittance is maximized and the liquid crystal becomes transparent when no voltage is applied to the liquid crystal. The light modulating layer 30 may be configured as normally clear so that the orientation at the time of light blocking is formed at the time of voltage application.

Although the light modulating layer 30 of the present embodiment is a guest-host type liquid crystal cell, it may be configured as a liquid crystal cell that does not use a dichroic dye composition. In this case, by further providing a linear polarizing layer, it can be made to function as a light control cell.
Various driving methods such as TN (Twisted Nematic) method, VA (Vertical Alignment) method, and IPS (In-Plane-Switching) method are known as driving methods of liquid crystal. It can be selected and used.

FIG. 8 is a diagram showing how the liquid crystal material of the light control layer 30 is oriented. In FIG. 8, only the

transparent electrodes

32A and 32B, the alignment layers 33A and 33B, and the liquid crystal material (the liquid crystal composition 36a and the dichroic dye 36b) are shown for easy understanding. indicates the time when light is shielded (no voltage application), and FIG. 8(b) indicates the time when light is transmitted (when voltage is applied).
Since the light-modulating layer 30 of the present embodiment is normally dark, as shown in FIG. , so that the liquid crystal composition 36a and the dichroic dye 36b are horizontally aligned in one direction, that is, the long axis direction of the liquid crystal composition 36a and the dichroic dye 36b is in one direction and parallel to the

transparent electrodes

32A and 32B and the alignment layers 33A and 33B. (the so-called horizontal direction). In this state, most of the light incident on the light modulating layer 30 (lights La and Lb shown in FIG. 8A) is absorbed by the dichroic dye 36b regardless of the incident angle, and the transmittance is reduced to It becomes the minimum light blocking state.

Further, since the light control layer 30 of the present embodiment is normally dark, as shown in FIG. 36b is vertically aligned in one direction, that is, the long axis direction of the liquid crystal composition 36a and the dichroic dye 36b is in one direction, and the

transparent electrodes

32A, 32B and the alignment layers 33A, 33B and oriented in the vertical direction (the so-called vertical direction). In this state, of the light incident on the light control layer 30, light La that is incident at a small incident angle such as an incident angle of 0° or near 0° is transmitted through the liquid crystal layer 36 (light control layer 30). However, as the incident angle increases, the light absorptivity of the dichroic dye increases, and most of the light Lb incident on the light control layer 30 obliquely at a large incident angle is absorbed by the dichroic dye 36b. is absorbed by the light, and the transmittance is greatly reduced. That is, the light modulating layer 30 has a higher absorptivity for light incident at a large incident angle than for light incident at a small incident angle such as 0° or near 0°.
Therefore, when a voltage is applied, the light modulating layer 30 has a high transmittance for light in a direction parallel to its thickness direction (Z direction), and as the incident angle increases, the transmittance decreases, and the light transmittance increases obliquely to the thickness direction. A state of low transmittance is obtained for light incident from a direction at a large incident angle. In this embodiment, such a state of the light modulating layer 30 is referred to as a translucent state.
In this embodiment, the large incident angle is defined as an incident angle of 40° or more.

By providing such a light modulating layer 30, the following effects can be obtained.
When the light-modulating layer 30 is in the light-shielding state, the light-modulating layer 30 absorbs a large amount of light regardless of the incident angle, resulting in a black screen state. Therefore, by projecting the image light from the image source LS onto the screen 20 with the light control layer 30 in the light shielding state, the black luminance of the image can be lowered and the contrast of the image can be greatly improved.
In addition, when the screen 20 does not have the light control layer 30, the image light transmitted through the reflection layer 13 is totally reflected by the air interface on the back side of the screen 20 and emitted from the surface on the image source side. However, the light modulating layer 30 of the screen 20 can absorb the image light that causes such double images, thereby greatly suppressing the image blur such as double images. display a clear image.
Furthermore, since the light modulating layer 30 absorbs the image light that passes through the reflection layer 13 and travels upward on the back side of the screen 20, reflection of the image on the ceiling on the back side of the screen 20 can be greatly suppressed.

Next, when the light-modulating layer 30 is in a light-transmitting state, the light-modulating layer 30 absorbs most of the external light such as sunlight and illumination light that enters from above the back side of the screen 20 at a large incident angle. , the transparency of the screen 20 in the front direction of the screen 20 can be sufficiently ensured. Therefore, the screen 20 is prevented from fogging (haze) caused by external light, and can improve its transparency.
When image light is projected with the light-modulating layer 30 in a light-transmitting state, much of the external light that enters from above the rear side of the screen 20 at a large angle of incidence is absorbed by the light-modulating layer 30 . Compared to screens without the light layer 30, the image contrast can be improved. In addition, although the effects of suppressing image blurring and suppressing reflection of images on the ceiling as described above are lower than in the light-shielded state, they can be expected.

FIG. 9 is a diagram showing an example of image light and external light incident on the screen 20 of the second embodiment. FIG. 9 shows an enlarged part of a cross section similar to the cross section of the screen 20 shown in FIG. Further, in FIG. 9, the configuration of the light control layer 30 is omitted for easy understanding. In addition, in FIG. 9, in order to facilitate understanding, it is assumed that there is no refractive index difference between the layers.
The image light L21 projected from the image source LS positioned below the screen 20 is incident on the light control layer 16 at an incident angle within the first incident angle range R1 and diffused to pass through the bonding layer 17a and the first base material layer. 11 and enters the first optical shaped layer 12 . The image light L22, which is a part of the image light L21, is diffusely reflected by the reflection layer 13 of the first slope 121a of the unit optical shape 121 and emitted to the image source side (+Z side). At this time, in the cross section of the screen 20 shown in FIG. 9, the image light L22 is incident on the light control layer 16 at an incident angle within the fourth incident angle range R4 (in particular, an incident angle of 0° and near 0°) from the rear side. Since the light is incident at a corresponding angle, it is emitted to the image source side without being diffused by the light control layer 16 and reaches the observer O1 side.

As described above, the image light L22 enters the light control layer 16 within the first incident angle range R1 and is diffusely reflected by the reflective layer 13 . Thereby, the image light L22 is preferably diffused, and the screen 20 can display an image with a sufficient viewing angle.
Further, the image light L22 is diffused by the light control layer 16 when incident on the screen 20 and is diffusely reflected by the reflection layer 13, so that it is diffused twice at different positions in the thickness direction of the screen 20. FIG. As a result, the screen 20 can reduce image glare (speckle) and suppress image blurring (decrease in resolution) due to excessive diffusion.

A part of the image light L23 of the image light L21 is transmitted through the reflection layer 13 toward the rear side, and transmitted through the second optical shape layer 14 to the surface of the light control layer 30 on the image source side. incident obliquely. Most of such image light L23 is absorbed by the light control layer 30 regardless of whether the light control layer 30 is in the light transmitting state or the light blocking state. Therefore, such image light L23 prevents the image from being displayed on the back side, and can suppress reflection of the image on the ceiling.

Next, external light such as sunlight and illumination light other than image light entering the screen 20 from the rear side (−Z side) or the image source side (+Z side) will be described.
When the light control layer 30 is in a light blocking state, external light G21 and G22 with a small incident angle to the screen 20, and external light incident on the screen 20 at a large incident angle from above the image source side and transmitted through the reflective layer 13 G25, most of the external light G26 that enters the screen 20 from above the back side at a large angle of incidence is absorbed by the light control layer 30, and the light control layer 30 (screen 20) appears black to the observers O1 and O2. Observed as a screen state.
Therefore, by projecting the image light L21 with the dimming layer 30 in the light shielding state, it is possible to display a good image with low black luminance and high contrast.

When the light-modulating layer 30 is in the light-transmitting state, most of the external light G21 and G22 with small incident angles to the screen 20 is not absorbed by the light-modulating layer 30, and as shown in FIG. It penetrates layer 30 . Further, the screen 20 does not include a layer (light diffusion layer) containing a diffusion material such as particles for diffusing light, the reflection layer 13 does not diffuse transmitted light, and external light G21 diffuses light. The external light G22 is incident on the control layer 16 from the image source side at an incident angle within the second incident angle range R2, and the external light G22 is incident on the light control layer 16 at an angle within the fourth incident angle range R4 from the rear side. Incident at a corresponding angle of incidence. Therefore, such outside lights G21 and G22 pass through the screen 20 without being diffused and are emitted to the rear side and the image source side, respectively, as shown in FIG.

Of the external light G23 incident on the screen 20 from above on the image source side, part of the external light (not shown) is reflected on the surface of the screen 40, but travels downward to reach the observers O1 and O2. do not have. In addition, most of the external light G23 enters the light control layer 16 from the image source side at an incident angle within the second incident angle range R2. Head inside to the back side. Part of the external light G24 of the external light G23 is reflected by the reflective layer 13, travels downward on the image source side of the screen 20, and is emitted downward on the image source side of the screen 20, or The light is totally reflected by the surface on the source side, travels downward inside the screen 20 again, and is attenuated. Part of the external light G25 of the external light G23 passes through the reflective layer 13, travels downward on the back side of the screen 20, and enters the light control layer 30. FIG. As described above, when the light-modulating layer 30 is in the translucent state, the light-modulating layer 30 absorbs much of the light that is incident at large angles of incidence. Therefore, most of the external light G25 is absorbed by the light control layer 30 .

Part of the external light G26 that enters the screen 20 from above the back side is reflected by the surface of the light control layer 30 on the back side and travels downward on the back side of the screen, so that it reaches the observers O1 and O2. do not have. Also, most of the external light G26 is absorbed by the liquid crystal layer 36 of the light control layer 30 .

Therefore, when the light modulating layer 30 is in a light-transmitting state, the screen 20 can suppress fogging (haze) of the screen 20 due to external light incident from above the image source side or from the upper back side. When observers O1 and O2 positioned in the front direction on the back side observe the scenery on the other side of the screen 20 through the screen 20, the scenery on the other side of the screen 20 is observed without blurring or whitening. and the screen 20 can exhibit high transparency.
Further, if image light is projected with the light control layer 30 in a light-transmissive state, the transparency of the screen 20 can be maintained while suppressing a decrease in contrast due to external light and reducing image glare.

From the above, according to the present embodiment, as in the first embodiment, it is possible to suppress the glare of the image, and to suppress the blurring of the image such as the double image (decrease in resolution). It can display clear images, does not diffuse unnecessary external light, and can display images with high contrast and transparency.
In particular, when image light is projected with the light modulating layer 30 in the light shielding state, a clear image with high contrast can be displayed.
Furthermore, according to the present embodiment, image blurring such as double images can be suppressed while improving the flatness of the screen surface.
Furthermore, according to the present embodiment, it is possible to appropriately select and set the light control layer 30 to be in a light transmitting state or a light blocking state according to the image to be displayed and the usage environment of the screen 20 or the like, so convenience is achieved. can be improved.
Furthermore, according to this embodiment, it is possible to further suppress reflection of the image on the ceiling or the like on the back side of the screen.

(Third Embodiment)
The third embodiment differs from the first embodiment in that the screen 40 includes the light control layer 30 shown in the second embodiment and the translucent substrate layer 48 . This screen 40 can be applied to the image display device 1 in place of the screen 10 of the first embodiment.
In the third embodiment and the like, portions that perform the same functions as those of the first and second embodiments described above are denoted by the same reference numerals or the same reference numerals at the end thereof, and overlapping descriptions are omitted as appropriate.

FIG. 10 is a diagram showing the layer structure of the screen 40 of the third embodiment. In FIG. 10, one cross section passing through the screen center (geometric center of the screen) of the screen 40, parallel to the vertical direction (Y direction) of the screen, and orthogonal to the screen surface (parallel to the Z direction). part is enlarged.
As shown in FIG. 10, the screen 40 includes, in order from the image source side (+Z side) in the thickness direction (Z direction), the light control layer 16, the bonding layer 17a, the translucent substrate layer 48, the bonding layer 17b, It includes a first substrate layer 11, a first optically shaped layer 12, a reflective layer 13, a second optically shaped layer 14, a second substrate layer 15, a bonding layer 17c, a light control layer 30, and the like.
In this embodiment, the screen 40 is not bonded to a support plate or the like. A support plate or the like may be joined. By laminating such a support plate on the screen 40, the flatness of the screen surface can be further improved.

The bonding layer 17b is a layer having a function of integrally bonding the translucent substrate layer 48 and the first base layer 11 together. For the bonding layer 17b, an adhesive material, an adhesive material, or the like having high optical transparency can be used.
The translucent substrate layer 48 is a plate-shaped member with high translucency. The translucent substrate layer 48 is thicker than the first base layer 11, the second base layer 15, and the like, and has a rigidity sufficient to maintain the flatness of the screen surface of the screen 40. As shown in FIG. The translucent substrate layer 48 is provided on the image source side of the first base material layer 11 via the bonding layer 17b.
Such a translucent substrate layer 48 is preferably made of highly translucent acrylic resin, polycarbonate resin, glass, or the like.
Moreover, it is preferable that the translucent substrate layer 48 has a thickness of 3 mm or more and 8 mm or less from the viewpoint of maintaining sufficient flatness of the screen surface. The thickness of the translucent substrate layer 48 is selected according to the screen size of the screen, etc., and so as to satisfy a preferable range of the distance D1, which will be described later.

In this embodiment, in the thickness direction (Z direction) of the screen 40, the distance from the surface on the back side (−Z side) of the light control layer 16 to the surface on the image source side (+Z side) of the first optical shape layer 12 D1 is greater than the distance D2 from the image source side surface of the light control layer 30 to the back side surface of the second optical shape layer 14 .
In addition, the distance D1 is more than 0.5 mm and 8 mm or less. By securing a sufficient distance between the light control layer 16 and the reflective layer 13, glare in the image can be more effectively reduced. It is preferable from the viewpoint of displaying a clear image by suppressing image blurring while maintaining the transparency of the screen and displaying an image with less distortion.

Returning to FIG. 10, the bonding layer 17c is a layer having a function of bonding the second base material layer 15 and the light control layer 30 together. For the bonding layer 17c, similarly to the bonding layers 17a and 17b described above, an adhesive material, a pressure-sensitive adhesive, or the like having high optical transparency can be used.

FIG. 11 is a diagram showing an example of image light and external light incident on the screen 40 of the third embodiment. FIG. 11 shows an enlarged part of a cross section similar to the cross section of the screen 40 shown in FIG. Further, in FIG. 11, the configuration of the light control layer 30 is omitted for easy understanding. Furthermore, FIG. 11 shows that there is no refractive index difference between layers for easy understanding.
First, image light will be described.
The image light L41 projected from the image source LS positioned below the screen 40 is incident on the light control layer 16 at an incident angle within the first incident angle range R1 and diffused to pass through the bonding layer 17a and the translucent substrate layer. 48 , the bonding layer 17 b , and the first substrate layer 11 to enter the first optically shaped layer 12 . The image light L42, which is a part of the image light L41, is diffusely reflected by the reflection layer 13 of the first slope 121a of the unit optical shape 121 and emitted to the image source side (+Z side). At this time, in the cross section of the screen 40 shown in FIG. 11, the image light L42 is incident on the light control layer 16 at an incident angle within the fourth incident angle range R4 (in particular, an incident angle of 0° and near 0°) from the back side. Since the light is incident at a corresponding angle, it is emitted to the image source side without being diffused by the light control layer 16 and reaches the observer O1 side.

Therefore, the image light L42 enters the light control layer 16 within the first incident angle range R1 and is diffusely reflected by the reflective layer 13 . Thereby, the image light L42 is preferably diffused, and the screen 40 can display an image with a sufficient viewing angle.
Further, the image light L42 is diffused by the light control layer 16 when incident on the screen 40, and is diffusely reflected by the reflection layer 13. Therefore, the image light L42 is diffused twice at different positions in the thickness direction (Z direction) of the screen 40. . As a result, the screen 40 can reduce image glare (speckle) and suppress image blurring (decrease in resolution) due to excessive diffusion.
In addition, the screen 40 includes the translucent substrate layer 48, and the distance D1 from the back side surface of the light control layer 16 to the image source side surface of the first optical shape layer 12 is sufficiently ensured as described above. Therefore, the effect of reducing the glare (speckle) of the image can be further enhanced, and the clarity of the image can be maintained. Moreover, since the translucent substrate layer 48 is provided, the flatness of the screen surface can be improved and the distortion of the image can be reduced.

In addition, part of the image light L43 of the image light L41 passes through the reflection layer 13 and travels toward the rear side, passes through the second optical shape layer 14 and the like, travels upward toward the rear side, and reaches the light control layer 30. Incident. As described above, regardless of whether the light-modulating layer 30 is in the light-shielding state or the light-transmitting state, the image light L43, which has a large incident angle (this In the embodiment, most of light incident at an incident angle of 40° or more is absorbed by the liquid crystal layer 36 .
When such image light L43 reaches the ceiling on the back side, it causes reflection of the image on the ceiling. However, in the screen 40 of the present embodiment, the image light L43 is absorbed by the light control layer 30, so that reflection of the image on the ceiling can be greatly reduced.

As described above, when the light modulating layer 30 is in the light blocking state, the light modulating layer 30 absorbs most of the incident light regardless of the angle of incidence on the light modulating layer 30 . Therefore, in the case where the light control layer 30 is not provided, image blur such as a double image caused by the total reflection of the image light L43 at the air interface on the back side of the screen and emitted to the image source side can be prevented. It can be greatly suppressed and a clear image can be displayed. In addition, it is possible to suppress the display of a left-right reversed image on the back side of the screen 40 by such image light L43.
Note that when the light-modulating layer 30 is in the light-transmitting state, the light-modulating layer 30 absorbs most of light with a large incident angle (light with an incident angle of 40° or more). Therefore, most of the light having a large incident angle with respect to the light control layer 30 is absorbed by the light control layer 30 in the image light L43. Therefore, when the light-modulating layer 30 is in the light-transmitting state, the effect of reducing image blurring such as double images as described above can be obtained. Are better.

Next, when the light control layer 30 is in a light blocking state with respect to external light such as sunlight and illumination light other than image light incident on the screen 40 from the back side (−Z side) or the image source side (+Z side), Each of the light-transmitting states will be described.
When the light modulating layer 30 is in the light blocking state, the light modulating layer 30 absorbs most of the incident light regardless of the incident angle to the light modulating layer 30 . Therefore, the external light G41 and G42 having a small incident angle to the screen 40 enters the screen 40 from above the image source side at a large incident angle (in this embodiment, the incident angle is 40° or more) and is transmitted through the reflective layer 13. Most of the light G45 and the external light G46 that enters the screen 40 from above the back side at a large angle of incidence are absorbed by the light control layer 30, and the observers O1 and O2 feel that the light control layer 30 (screen 40) It is observed as a black screen state.
Therefore, by projecting the image light L41 when the light control layer 30 is in the light blocking state, a good image with low black luminance and high contrast can be displayed.

When the light-modulating layer 30 is in the light-transmitting state, most of the external light G41 and G42 with a small incident angle to the screen 40 is not absorbed by the light-modulating layer 30, and as shown in FIG. It is transmitted through the optical layer 30 . In addition, the screen 40 does not include a layer (light diffusion layer) containing a diffusion material such as particles that diffuse light, and the reflection layer 13 does not diffuse transmitted light. , G42 pass through the screen 40 without being diffused, and are emitted to the rear side and the image source side, respectively, as shown in FIG.

Next, part of the external light G43 incident on the screen 40 from above on the image source side (not shown) is reflected on the surface of the screen 40, and travels downward toward the screen, thereby illuminating the viewers O1 and O2. does not reach Most of the external light G43 is incident on the screen 40, and part of the external light G44 is reflected by the reflective layer 13 and travels downward on the image source side of the screen 40, and downward on the image source side of the screen 40. The light is emitted, or it is totally reflected by the surface of the screen 40 on the image source side and directed downward inside the screen 40 again to be attenuated. Part of the external light G45 of the external light G43 passes through the reflective layer 13 and enters the light control layer 30 toward the lower side of the screen 40 on the back side. When the light-modulating layer 30 is in the light-transmitting state, the light-modulating layer 30 absorbs external light G45 that forms a large incident angle with respect to the light-modulating layer 30 .

The external light G46 that enters the screen 40 from above the back side enters the light control layer 30 at a large angle of incidence. As described above, when the light-modulating layer 30 is in the light-transmitting state, the light-modulating layer 30 absorbs most of the light incident at a large incident angle (in this embodiment, the incident angle is 40° or more). Most of the light G46 is absorbed by the light modulating layer 30 . Although part of the external light G46 is reflected by the back surface of the light control layer 30, it travels downward on the back side of the screen and does not reach the observers O1 and O2.

Therefore, when the light modulating layer 30 is in a light-transmitting state, the screen 40 can suppress fogging (haze) of the screen 40 due to external light incident from above the image source side or from the upper back side. When observers O1 and O2 positioned in the front direction on the back side observe the scenery on the other side of the screen 40 through the screen 40, the scenery on the other side of the screen 40 can be observed without blurring or whitening. and the screen 40 can exhibit high transparency.
Further, if image light is projected with the light modulating layer 30 in a light-transmissive state, the transparency of the screen 40 can be maintained while suppressing deterioration of image contrast due to external light.

According to this embodiment, the image light is not diffused after being diffusely reflected by the reflective layer 13, so the screen 40 can display a high-resolution image.
In addition, according to the present embodiment, the screen 40 can maintain its transparency, and can significantly suppress a decrease in image contrast due to diffusion of external light.
Further, according to this embodiment, the image light transmitted through the reflective layer 13 is diffused by the light control layer 16 and absorbed by the light control layer 30, so that the image on the ceiling or the like on the back side of the screen 40 is reflected. can greatly improve the reflection of

Further, according to the present embodiment, it is possible to appropriately select and set the light control layer 30 to be in the light transmitting state or the light blocking state according to the image to be displayed, the environment in which the screen 40 is used, etc. Therefore, it is convenient. can be improved.
Further, in the screen 40 of the present embodiment, the distance D1 from the back side surface of the light control layer 16 to the image source side surface of the first optical shape layer 12 in the thickness direction is equal to the image source of the light control layer 30. It is greater than the distance D2 from the side surface to the back side surface of the second optical shaped layer 14 . Therefore, the screen 40 can ensure a sufficient distance between the light control layer 16 in which the image light is diffused and the reflective layer 13 in the thickness direction (Z direction), thereby reducing image glare. The effect can be further enhanced.
In addition, since the screen 40 of the present embodiment includes the translucent substrate layer 48, the flatness of the screen 40 can be improved and image distortion can be suppressed.

(Evaluation of image glare, etc.)
Here, the screen of Example 2, which corresponds to the example of the screen 40 of the third embodiment, and the screens of Comparative Examples 3 to 7, which correspond to comparative examples, were prepared, and the effect of reducing the glare of the image and the clarity of the image were obtained. It was evaluated with respect to
The screens of Example 2 and Comparative Examples 3 to 7 all have a screen size of 40 inches.
The screen of Example 2 corresponds to an example of the screen 40 of the present embodiment, and includes the light control layer 16, the bonding layer 17a, the translucent substrate layer 48, the bonding layer 17b, the first base material layer 11, the first optical A shaped layer 12 , a reflective layer 13 , a second optically shaped layer 14 , a second substrate layer 15 , a bonding layer 17 c and a light control layer 30 are provided.

The screen of Comparative Example 3 has the same translucent substrate layer 48, bonding layer 17b, first substrate layer 11, first optically shaped layer 12, reflective layer 13, and second optically shaped layer as in the screen 40 of the present embodiment. 14, the second base material layer 15, the bonding layer 17c, and the light control layer 30 are provided, but the bonding layer 17a and the light control layer 16 are not provided.
Compared to the screen of Comparative Example 3, the screen of Comparative Example 4 corresponds to a mode in which a light diffusion layer, not the light control layer 16, is laminated on the image source side of the first base material layer 11 via the bonding layer 17a. . This light diffusion layer is a layer made of resin containing particles that diffuse light, and has the characteristic of diffusing light regardless of the incident angle of light.

The screen of Comparative Example 5 includes the light control layer 16, the bonding layer 17a, the translucent substrate layer 48, the bonding layer 17b, the first base layer 11, the first optical shape layer 12, the same as the screen 40 of this embodiment. Although the reflective layer 13, the second optical shape layer 14, and the second base material layer 15 are provided, the bonding layer 17c and the light control layer 30 are not provided.
The screen of Comparative Example 6 includes the light control layer 16, the bonding layer 17a, the first base material layer 11, the first optically shaped layer 12, the reflective layer 13, the second optically shaped layer 14, the same as the screen 40 of the present embodiment. Although the second base material layer 15, the bonding layer 17c, and the light control layer 30 are provided, the translucent substrate layer 48 and the bonding layer 17b are not provided.
The screen of Comparative Example 7 has the same translucent substrate layer 48, bonding layer 17b, first substrate layer 11, first optically shaped layer 12, reflective layer 13, and second optically shaped layer 14 as in the screen 40 of the embodiment. , the second substrate layer 15 is provided, but the light control layer 16, the bonding layer 17a, the bonding layer 17c, and the light control layer 30 are not provided.

The details of the layers common to the screens of Example 2 and Comparative Examples 3 to 7 are as follows.
The first base material layer 11 is made of a polycarbonate resin having a refractive index of 1.59 and a thickness of 0.075 mm.
The first optical shape layer 12 is made of an ultraviolet curable resin (urethane acrylate) with a refractive index of 1.51, and its thickness changes in the arrangement direction of the unit optical shapes 121 depending on the height h of the unit optical shapes 121. However, it is 0.01 mm at the center of the lower edge of the screen and 0.14 mm at the center of the upper edge of the screen.

Further, the light control layer 16 of the screens of Example 2 and Comparative Examples 5 and 6 is a visual field control film Y-2555 manufactured by Lintec Corporation.
The translucent substrate layer 48 of the screens of Example 2 and Comparative Examples 3 to 5 and 7 is made of acrylic resin, and has a thickness of 6 mm and a refractive index of 1.49.

Regarding the screens of Example 2 and Comparative Examples 3 to 7, visual evaluation was performed to determine the glare and clarity of the image, the transparency of the screen, the presence or absence of reflection of the image on the ceiling (so-called ceiling ghost), and the contrast of the image. , the presence or absence of image distortion, etc. were evaluated. In the visual evaluation, the light-modulating layer 30 was in a translucent state (with voltage applied) when evaluating the transparency of the screen, and was in a light-shielding state (with no voltage applied) for other evaluations.
FIG. 12 is a diagram showing each screen, the image source LS, the positions of the observer O3, etc. at the time of visual evaluation. FIG. 12A shows the positions of each screen, image source LS, and observer O3 at the time of visual evaluation as viewed from the side (+X side). FIG. 12(b) shows the positions of each screen, image source LS, and observer O3 at the time of visual evaluation as viewed from above (+Y side). The installation position of the image source LS is a position according to the instruction manual of the image source LS used, and the incident angle θ of the image light at the point A in the cross section shown in FIG. 50°.

Regarding the glare of the image, in a darkroom environment, with respect to the screens of Example 2 and Comparative Examples 3 to 7, with a white screen projected from the image source LS, from the point A which is the center of the screen of each screen Observer O3 observed and evaluated the central portion of each screen from a position of 1 m on the image source side (+Z side).

Regarding the clarity of the image, the screens of Example 2 and Comparative Examples 3 to 7 were projected in a darkroom environment with a still image (white characters on a black background) from the image source LS. An observer O3 observed and evaluated the central portion of each screen from a position 1 m from the center point A on the image source side (+Z side).
Regarding the transparency of the screen, the screens of Example 2 and Comparative Examples 3 to 7 were tested in a bright room environment (illuminance of 700 lx at point A at the center of the screen) without projection of an image from the image source. Observer O3 observed and evaluated the central portion of each screen from a position of 1 m on the image source side (+Z side) from point A, which is the center of each screen.

The presence or absence of the reflection of the image on the ceiling (so-called ceiling ghost) was determined by displaying a still image (white characters on a black background) from the image source LS in a darkroom environment for the screens of Examples and Comparative Examples 1 to 5. In the projected state, the image light transmitted through each screen reached the ceiling 1.5 m above (+Y side) on the back side (-Z side) of each screen and observed the displayed image. evaluated. At this time, since the space between each screen and the ceiling is an open space, the observer O3 can see the above ceiling from a position 1 m away from the center point A of the screen on the image source side (+Z side). was observed and evaluated.

Regarding the feeling of contrast, in the screens of Example 2 and Comparative Examples 3 to 7, in a bright room environment (illuminance at point A at the center of the screen: 700 lx), a still image (overall black pattern) from the image source LS is projected, observer O3 observes the central part of each screen from a position of 1 m from point A, which is the center of the screen of each screen, to the image source side (+Z side), and evaluates the blackness of the image. .
Regarding image distortion, the screens of Example 2 and Comparative Examples 3 to 7 were allowed to display a still image (white lattice pattern on a black background) from the image source LS in a darkroom environment, and the screen of each screen was An observer O3 observed the central portion of each screen from a position 1 m away from the center point A on the image source side (+Z side), and visually evaluated the distortion of the display pattern.
In each evaluation, there were three observers O3, and the evaluation results were taken as the average.

Table 2 shows the evaluation results of the screens of Example 2 and Comparative Examples 3-7.
In Table 2, glare is indicated by ⊙ when the glare of the image is not visually recognized, indicated by ○ when the glare is within the allowable range but is slightly visible, and is visually uncomfortable. It was indicated by x as being unacceptable.
In addition, in Table 2, the clarity of the image is indicated by ⊚ when a clear image without image blur including double images is visually recognized. Some samples were evaluated as acceptable and marked with ◯, while images unsuitable for use due to blurred images were rated as poor and marked with x.

In Table 2, the transparency of the screen is indicated by ⊙ when the transparency is high, and by ◯ when the transparency is slightly inferior to the good but sufficient transparency for use. When the transparency was impaired, such as when the other side of the screen looked white and turbid, the result was marked as unsatisfactory.
In Table 2, the presence or absence of reflection of the image on the ceiling (so-called ceiling ghost) is indicated by ◎ when the image pattern projected on the ceiling cannot be recognized by the image light transmitted through the screen. When the image pattern was recognizable but unclear compared to , it was indicated by ◯, and when the image pattern was clearly recognizable, it was indicated by ×.

In addition, in Table 2, the contrast feeling is indicated by ⊙ when the display of the entire black pattern is perceived as black, and is indicated by ◯ when the blackness is inferior to good but can be recognized as being within the allowable range. , and those that were inferior to acceptable and felt discomfort in blackness were indicated by x as failure.
In Table 2, the presence or absence of distortion in the image was indicated by ⊚ when the lattice pattern was perceived as uniform, and by x when the linearity was inferior to good and the impression of non-uniformity was perceived as unacceptable.

The overall evaluation is an evaluation that considers visual glare and image clarity, screen transparency, image reflection on the ceiling, contrast, and image distortion for each screen. The images should have reduced glare, be clear and sufficiently transparent, should not be reflected on the ceiling, should have a high contrast, and should not be distorted. Those that are inferior to good but usable are indicated by ◯, and those that are not suitable for use are indicated by ×.

As shown in Table 2, the screen of Comparative Example 3, which did not have the light control layer 16, displayed a clear image, had a good contrast feeling, had no distortion in the image, had transparency of the screen, and could not be seen from the ceiling. Although the effect of reducing image reflection was obtained, the image glare occurred, which is not preferable.
Further, in the screen of Comparative Example 4, in which the light diffusion layer instead of the light control layer 16 is provided on the image source side of the first base material layer 11, glare in the image is effectively suppressed. There was no distortion, and the reflection of images on the ceiling was well reduced. However, in the screen of Comparative Example 4, the image was dark and unclear (large image blur), and the transparency and contrast of the screen were greatly reduced. This is probably because the light diffusion layer diffuses light irrespective of the incident angle of the light, so external light such as illumination light is also diffused.

In addition, the screen of Comparative Example 5 had no glare in the image, no distortion in the image, good reduction in reflection of the image on the ceiling, and sufficient transparency of the screen. However, in the screen of Comparative Example 5, image blurring such as double images occurred, the clarity of the image was lowered, and the contrast was also lowered, which was not preferable.
Furthermore, the screen of Comparative Example 6 was excellent in the clarity of the image and the reduction of reflection of the image on the ceiling, and the transparency of the screen, the suppression of the glare of the image, and the contrast were sufficient. However, since the screen of Comparative Example 6 did not include the translucent substrate layer 48, the distortion of the image was large, which was not preferable.
Furthermore, in the screen of Comparative Example 7, the clarity of the image and the absence of distortion of the image were good, and the transparency of the screen was sufficient. This was not preferable because the contrast was greatly reduced.

On the other hand, the screen of Example 2 was able to greatly reduce the glare of the image, had no image distortion, and had sufficient image clarity, screen transparency, and contrast. In addition, in the screen of Example 2, the reflection of the image on the ceiling on the back side of the screen was not visually recognized, which was greatly improved.
As described above, according to the present embodiment, it is possible to provide the screen 40 and the image display device 1 capable of displaying a clear image, reducing glare of the image, and having sufficient transparency.
Further, according to the present embodiment, by setting the light control layer 30 in the light shielding state, it is possible to display an image with a better sense of contrast. Moreover, according to the present embodiment, the flatness of the screen surface can be improved, and good images without distortion can be displayed.
Further, according to the present embodiment, it is possible to provide the screen 40 and the image display device 1 that can greatly suppress the reflection of the image on the ceiling or the like on the back side of the screen.

(Another form of the third embodiment)
In the above-described third embodiment, the screen 40 is provided with the translucent substrate layer 48, but this is not restrictive, and the first substrate layer 11 does not have the translucent substrate layer 48 and has a sufficient thickness. and rigidity.
Even in such a configuration, the distance D1 from the back side surface of the light control layer 16 to the image source side surface of the first optical shape layer 12 in the thickness direction of the screen 40 is It is preferable that the distance D2 from the surface on the source side to the surface on the back side of the second optical shape layer 14 is greater than D1, and the distance D1 is greater than 0.5 mm and 8 mm or less to reduce image clarity and image glare. It is preferable from the viewpoint of obtaining both effects of reduction.
According to this embodiment, similarly to the above-described third embodiment, it is possible to reduce the glare of an image and display a clear image. Also in this embodiment, the transparency of the screen can be maintained, and reflection of images on the ceiling on the back side of the screen can be improved. In addition, in this embodiment, the number of layers constituting the screen can be reduced more than in the above-described embodiment, the reflection loss of light at the interface is reduced, the transparency of the screen is improved, the brightness of the image is improved, etc. can be achieved.

(Fourth embodiment)
The fourth embodiment differs from the first embodiment in that the screen 70 does not include the light control layer 16 but includes the light control layer 30 . This screen 70 can be applied to the image display device 1 in place of the screen 10 of the first embodiment.
In the fourth embodiment and the like, portions that perform the same functions as those of the first and second embodiments described above are given the same reference numerals or the same reference numerals at the end thereof, and duplicate descriptions thereof will be omitted as appropriate.
FIG. 13 is a diagram showing the layer structure of the screen 70 of the fourth embodiment. In FIG. 13, one cross-sectional view passes through the screen center (geometric center of the screen) of the screen 70, is parallel to the vertical direction (Y direction) of the screen, and is orthogonal to the screen surface (parallel to the Z direction). part is enlarged.
As shown in FIG. 13, the screen 70 includes the first substrate layer 11, the first optical shape layer 12, the reflective layer 13, the second It includes an optical shape layer 14, a second base material layer 15, a bonding layer 17c, a light control layer 30, and the like.

The light control layer 30 has the same shape as the light control layer 30 shown in the second embodiment and the like. Here, the light modulating layer 30 will be further described.
This light modulating layer 30 is normally dark, and in the transmissive state (when an electric field is applied), as described above, the transmittance of light at an incident angle of 0° is maximized, and the transmittance increases as the incident angle increases. rate drops.
On the other hand, the colored layer, which is a general light absorption layer that contains a coloring material or the like having a light absorption action, absorbs part of the incident light and transmits part of it, has a front transmittance (incident angle The rate of decrease in the transmittance of light incident from an oblique direction is small relative to the transmittance of light incident at 0 and emitted at an emission angle of 0°.

FIG. 14 is a diagram for explaining a method of measuring the change in transmittance depending on the incident angle in Samples 1 to 3. FIG.
As shown in FIG. 14, a sample 1 corresponding to the light control layer 30 of the present embodiment, a sample 2 corresponding to the colored layer as a comparative example, and a sample 3 as an LCD panel as a comparative example were each prepared in a dark room environment. is laminated on a plate-shaped member (acrylic plate) E1 made of acrylic resin having high light transmittance, and light is irradiated from the light source E2 for measurement at a predetermined incident angle θ1 from the side of the acrylic plate E1. Then, a light receiver E3 (MCPD6800 spectroscope manufactured by Otsuka Electronics Co., Ltd.) is placed in the direction of the output angle θ1 on the surface on the sample side, and the transmittance of the output light in the output angle θ1 direction is measured, and the front transmittance ( The decrease rate of the transmittance of light incident from an oblique direction with respect to the transmittance of light having an incident angle of 0° in the direction of an output angle of 0° was calculated. In this measurement, it is assumed that the light modulating layer 30, which is the sample 1, is in a translucent state in which a voltage is applied.

Sample 1 corresponds to an example of the light modulating layer 30 of this embodiment and has a thickness of 0.26 mm. In Sample 1, the

substrates

31A and 31B are PET resin films having a thickness of 0.125 mm, and the

transparent electrodes

32A and 32B are made of ITO. The liquid crystal layer 36 is formed of a guest-host type liquid crystal composition using a dichroic dye composition. This sample 1 has a front transmittance of 29% in the transmissive state.
Sample 2 is a sheet-like member made of acrylic resin containing a coloring material, and has a thickness of 1 mm. Sample 2 has a front transmittance of 2.3%.
Sample 3 is a normally white LCD panel that includes a liquid crystal layer driven by the TN method, and includes the same liquid crystal layer, transparent electrode, base material, etc. as the light control layer 30 of the present application. , and polarizing plates (not shown) are provided on the image source side and the back side thereof.
The LCD panel of this sample 3 has a horizontally long rectangular shape, and is laminated on the acrylic plate E1 so that the side surface seen from the direction parallel to the long side direction is shown in the state at the time of transmittance measurement shown in FIG. be. In this sample 3, when the panel surface is viewed from the front, the transmission axis of the polarizing plate (not shown) is 45° with respect to the vertical direction (short side direction) of the panel surface. has a front transmittance of 0.75%. Moreover, the sample 3 has a thickness of 1.6 mm.

FIG. 15 is a graph showing the rate of decrease in the transmittance of obliquely incident light with respect to the front transmittance of samples 1 to 3. The vertical axis represents the reduction rate (%) of the transmittance of light incident from an oblique direction with respect to the front transmittance (the transmittance in the direction of the output angle of 0° for light with an incident angle of 0°), and the horizontal axis represents the incident angle. (°). FIG. 15 shows the rate of decrease when the incident angle is 40° or more and 80° or less.

Table 3 is a table showing the rate of decrease in the transmittance of obliquely incident light with respect to the front transmittance for each incident angle of samples 1 to 3.
As shown in FIG. 15 and Table 3, in the sample 2 corresponding to the light absorption layer of the comparative example, the decrease rate at the incident angle of 40° was 50.4%, and the decrease rate at the incident angle of 50° was 59%. 9%, the rate of decrease at an incident angle of 60° was 76.1%, the rate of decrease at an incident angle of 70° was 87.6%, and the rate of decrease at an incident angle of 80° was 89.3%.

Sample 3, which is a comparative example, has a larger reduction rate than Sample 2, with a reduction rate of 58.5% at an incident angle of 40° and a reduction rate of 72.5% at an incident angle of 50°. 8%, the rate of decrease at an incident angle of 60° was 84.6%, the rate of decrease at an incident angle of 70° was 94.4%, and the rate of decrease at an incident angle of 80° was 97.3%.

On the other hand, in Sample 1 corresponding to the example of the light modulating layer 30 of the present embodiment, the reduction rate at the incident angle of 40° was 71.7%, and the reduction rate at the incident angle of 50° was 81.7%. 1%, 90.5% at 60° incident angle, 95.6% at 70° incident angle, 96.8% at 80° incident angle, and 96.8% at 80° incident angle. The rate of decrease was greater than that of Samples 2 and 3 in the range of 80° or more. In particular, the rate of decrease in transmittance at an incident angle of 40° and an incident angle of 50° was about 21% greater for sample 1 than for sample 2. Sample 1 has a transmittance decrease rate at an incident angle of 40° that is 13.2% larger than Sample 3, and a transmittance decrease rate at an incident angle of 50° is 8.0% greater than that of Sample 3. 3% larger.
As described above, the screen 70 including the light control layer 30 as in the present embodiment transmits light from the front direction while transmitting light from an oblique direction when the light control layer 30 is in a translucent state. It can effectively absorb and block light (in particular, light with an incident angle of 40° or more).

FIG. 16 is a diagram showing an example of image light and external light incident on the screen 70 of the fourth embodiment. FIG. 16 shows an enlarged part of a cross section similar to the cross section of the screen 70 shown in FIG. Further, in FIG. 16, the configuration of the light control layer 30 is omitted for easy understanding. Also, in FIG. 16, for ease of understanding, it is assumed that there is no refractive index difference between the layers.
The image light L71 projected from the image source LS positioned below the screen 70 passes through the first base material layer 11 and enters the first optical shape layer 12 . Then, the image light L72, which is a part of the image light L71, is diffusely reflected by the reflection layer 13 of the first slope 121a of the unit optical shape 121, emitted to the image source side (+Z side), and reaches the observer O1 side. . The image light L72 is diffusely reflected by the reflective layer 13, and the screen 70 can display an image with a sufficient viewing angle.

Note that the image light L71 is projected from below the screen 70, and the angle β (see FIG. 13) is larger than the incident angle of the image light L71 at each point in the vertical direction (Y direction) of the screen 70. , the image light L71 does not directly enter the second slope 121b, and the second slope 121b does not contribute to the reflection of the image light.
In addition, part of the image light L73 of the image light L71 is transmitted through the reflection layer 13 and directed toward the back side, and is transmitted upward through the second optical shape layer 14 and the like, toward the light control layer 30. Incident. As described above, regardless of whether the light-modulating layer 30 is in the light-blocking state or the light-transmitting state, the light, such as the image light L73, which is incident on the light-modulating layer 30 at a large angle of incidence, is light-modulated. It is absorbed in the liquid crystal layer 36 of layer 30 .
When such image light L73 reaches the ceiling on the back side, it causes reflection of the image on the ceiling. However, in the screen 70 of the present embodiment, the image light L73 is absorbed by the light control layer 30, so that reflection of the image on the ceiling can be greatly reduced.

Further, as described above, when the light-modulating layer 30 is in the light-shielding state, the light-modulating layer 30 absorbs most of the incident light regardless of the angle of incidence on the light-modulating layer 30 . Therefore, in the case where the light control layer 30 is not provided, image blur such as a double image caused by total reflection of the image light L73 at the air interface on the back side of the screen and emitted to the image source side can be prevented. It can be greatly suppressed and a clear image can be displayed. In addition, it is possible to suppress the display of a left-right reversed image on the back side of the screen 70 by such image light L73.
Further, when the light-modulating layer 30 is in the light-transmitting state, the light-modulating layer 30 absorbs most of the light with a large incident angle, that is, the light with an incident angle of 40° or more. Therefore, of the image light L<b>73 , most of the light having an incident angle of 40° or more with respect to the light control layer 30 is absorbed by the light control layer 30 . Therefore, even when the light-modulating layer 30 is in the light-transmitting state, the effect of reducing image blurring such as double images as described above can be obtained, but when the light-modulating layer 30 is in the light-shielding state Its effect is better.

Next, when the light control layer 30 is in a light blocking state with respect to external light such as sunlight and illumination light other than image light incident on the screen 70 from the back side (−Z side) or the image source side (+Z side), The description will be made separately for the translucent state.
When the light modulating layer 30 is in the light blocking state, the light modulating layer 30 absorbs most of the incident light regardless of the incident angle to the light modulating layer 30 . Therefore, external light G71 and G72 with a small incident angle on the screen 70, external light G75 that has entered the screen 70 from above the image source side at a large incident angle and has passed through the reflective layer 13, and large incident light on the screen 70 from above the back side. Most of the external light G76 incident at an angle is absorbed by the light control layer 30, and the light control layer 30 (screen 40) is observed as a black screen state by the observers O1 and O2.
Therefore, by projecting the image light L71 when the light control layer 30 is in the light blocking state, a good image with low black brightness and high contrast can be displayed.

When the light-modulating layer 30 is in the light-transmitting state, most of the external light G71 and G72 with small incident angles to the screen 70 is not absorbed by the light-modulating layer 30, and is modulated as shown in FIG. It is transmitted through the optical layer 30 . In addition, the screen 70 does not include a layer (light diffusion layer) containing a diffusion material such as particles that diffuse light, and the reflection layer 13 does not diffuse transmitted light. , G72 pass through the screen 70 without being diffused, and exit to the rear side and the image source side, respectively.

Of the external light G73 incident on the screen 70 from above on the image source side, part of the external light (not shown) is reflected on the surface of the screen 70. does not reach Most of the external light G73 is incident on the screen 70, and part of the external light G74 is reflected by the reflective layer 13 and directed downward on the image source side of the screen 70, and downward on the image source side of the screen 70. The light is emitted, or it is totally reflected by the surface of the screen 70 on the image source side, travels downward inside the screen 70 again, and is attenuated. A part of the external light G75 of the external light G73 is transmitted through the reflective layer 13 and enters the light control layer 30 toward the lower side of the back side of the screen 70 . When the light-modulating layer 30 is in the light-transmitting state, most of the external light 75 incident on the light-modulating layer 30 at a large incident angle (incident angle of 40° or more) is absorbed by the light-modulating layer 30 . .

The external light G76 incident on the screen 70 from above the back side enters the light control layer 30 at a large incident angle. As described above, when the light-modulating layer 30 is in the light-transmitting state, the light-modulating layer 30 absorbs most of the light incident at a large incident angle (incidence angle of 40° or more). Absorbed at 30. Part of the external light G76 is reflected by the back surface of the light control layer 30, but travels downward on the back side of the screen and does not reach the observers O1 and O2.

Therefore, when the light modulating layer 30 is in a light-transmitting state, the screen 70 can suppress fogging (haze) of the screen 70 due to external light incident from above the image source side or from the upper back side. When observers O1 and O2 positioned in the front direction on the back side observe the scenery on the other side of the screen 70 through the screen 70, the scenery on the other side of the screen 70 can be observed without blurring or whitening. and the screen 70 can exhibit high transparency.
Further, if image light is projected with the light modulating layer 30 in a light-transmissive state, the transparency of the screen 70 can be maintained while suppressing deterioration of image contrast due to external light.

In a conventional reflective screen provided with a light diffusing layer containing a diffusing material such as particles that diffuse light, in addition to diffuse reflection on the reflective layer, image light is reflected before and after reflection on the reflective layer by the light diffusing layer. Since the light is diffused twice, the image light is diffused excessively, resulting in image blurring (decrease in resolution).
In contrast, according to the present embodiment, the image light is not diffused after being diffusely reflected by the reflective layer 13, so that a high-resolution image can be displayed.

In addition, in a conventional reflective screen provided with such a light diffusion layer, the light diffusion layer also diffuses unnecessary external light, so that the transparency of the screen decreases and the contrast of the image decreases. .
On the other hand, the screen 70 of this embodiment does not have such a light diffusion layer, and most of the outside light is transmitted through the screen without being diffused or is absorbed by the light control layer 30. Also, since the light is emitted outside the visible range of the observers O1 and O2, it is possible to greatly suppress the deterioration of the contrast of the image due to the diffusion of the outside light. Further, when the light modulating layer 30 is in a translucent state, the transparency of the screen 70 can be maintained.

As described above, according to the present embodiment, it is possible to display a clear image by suppressing image blurring (decrease in resolution). Further, according to the present embodiment, image light transmitted through the reflective layer is reflected on the ceiling or the like, and such image light is totally reflected on the back surface of the screen and emitted to the image source side. It is possible to suppress the double image caused by
In addition, according to the present embodiment, unnecessary external light is not diffused and reaches the observer, so that a high-contrast image can be displayed, and when the light control layer 30 is in the light-transmitting state, A highly transparent screen can be obtained.
Further, according to the present embodiment, it is possible to appropriately select and set the light control layer 30 to be in the light transmitting state or in the light blocking state according to the image to be displayed and the environment in which the screen 70 is used. can improve.

(Fifth embodiment)
The fifth embodiment differs from the first embodiment in that the screen 80 does not include the light control layer 16 but includes the light control layer 30 and translucent substrate layers 88 and 89 . This screen 80 can be applied to the video display device 1 in place of the screen 10 of the first embodiment.
In the fifth embodiment and the like, portions that perform the same functions as those of the first and second embodiments described above are denoted by the same reference numerals or the same reference numerals at the end thereof, and overlapping descriptions are omitted as appropriate.

FIG. 17 is a diagram showing the layer structure of the screen 80 of the fifth embodiment. In FIG. 17, one cross-sectional view passes through the screen center (geometric center of the screen) of the screen 80, is parallel to the vertical direction of the screen (Y direction), and is perpendicular to the screen surface (parallel to the Z direction). part is enlarged.
As shown in FIG. 17, the screen 80 includes, in the thickness direction (Z direction), the first substrate layer 11, the first optical shape layer 12, the reflective layer 13, the second It includes an optical shape layer 14, a second base material layer 15, a bonding layer 17c, a translucent substrate layer 88, a bonding layer 87a, a light control layer 30, a bonding layer 87b, a translucent substrate layer 89, and the like.

The light-transmitting

substrate layers

88 and 89 are plate-shaped members having high light-transmitting properties and being thicker than the first base material layer 11, the second base material layer 15, and the like. 89 is preferably made of float glass or tempered glass depending on the required strength. Further, the translucent substrate layers 88 and 89 preferably have a thickness of 0.5 mm or more and 8 mm or less.
The translucent substrate layer 88 is laminated on the image source side of the base material 31A via a bonding layer 87a, and the translucent substrate layer 89 is laminated on the back side of the base material 31B via a bonding layer 87b. .

For the joining

layers

87a and 87b, an adhesive material or adhesive material having high light transparency, a sheet-shaped member having light transparency and adhesiveness, or the like can be used. Also, the bonding layers 87a and 87b may be made of an intermediate film forming sheet or the like made of polyvinyl butyral resin (PVB resin).
That is, as shown in FIG. 17, in this embodiment, the light modulating layer 30 is sandwiched between two translucent substrate layers 88 and 89 via

bonding layers

87a and 87b. The light-transmitting

substrate layers

88 and 89 are larger than the light-modulating layer 30 when viewed from the thickness direction of the screen 80, and the outer edge of the light-transmitting layer 30 extends from the edge of the light-transmitting

substrate layers

88 and 89. The space up to the part may be filled with the bonding layers 87a and 87b.

According to this embodiment, in addition to the effects shown in the fourth embodiment, the following effects can be obtained.
According to the present embodiment, the liquid crystal material of the liquid crystal layer 36 falls in the direction of gravity at high temperature, causing uneven distribution of the liquid crystal material, and the light control layer 30 is in the light shielding state or the light transmitting state. It is possible to reduce the unevenness of the transmittance distribution.
Further, according to this embodiment, the flatness of the screen surface of the screen 80 can be improved by the two translucent substrate layers 88 and 89 .
In this embodiment, the screen 80 does not include the light control layer 16, but the present invention is not limited to this. 16 may be provided.
In this embodiment, the screen 80 shows an example in which the light control layer 30 is sandwiched between the light-transmitting

substrate layers

88 and 89. However, the screen 80 is not limited to this. A configuration in which one translucent substrate layer is laminated on the side may also be used.

(deformed form)
Various modifications and changes are possible without being limited to the embodiments described above, and they are also within the scope of the present invention.
(1) In each embodiment, the

screens

10, 20, 40, 70, 80 are provided with a hard coat layer for the purpose of preventing scratches on the surface of the image source side (+Z side) and the back side (−Z side). good too. The hard coat layer is formed, for example, by coating the

screens

10, 20, 40, 70, 80 on the image source side and the back side with an ultraviolet curable resin (for example, urethane acrylate, etc.) having a hard coat function. It is formed.

In addition to the hard coat layer, depending on the usage environment and purpose of use of the

screens

10, 20, 40, 70, 80, the surface of the image source side and the back side of the

screens

10, 20, 40, 70, 80 For example, one or a plurality of layers having appropriate necessary functions such as antireflection function, ultraviolet absorption function, antifouling function, and antistatic function may be selected and provided. Furthermore, a touch panel layer or the like may be provided on the image source side of the light control layer 16 .
In particular, when an antireflection layer is provided on the surface of the

screens

10, 20, 40, 70, 80 on the image source side, the reflection of image light on the screen surface is reduced to reduce the reflection of the image light on the

screens

10, 20, 40, 70, . In addition to the effect of increasing the amount of incident light to 80 and improving the brightness of the image, the image light reflected by the reflective layer 13 is reflected at the interface with the air on the image source side and emitted to the back side. It is possible to prevent the image from being displayed as if it were leaking to the side.
The layers having various functions such as the hard coat layer may be provided on either the image source side or the back side of the

screens

10, 20, 40, 70, 80. FIG.

(2) In the first and third embodiments, the

screens

10 and 40 are transparent.
FIG. 18 is a diagram showing the layer structure of a modified screen 50. As shown in FIG. The screen 50 of this modified form corresponds to a modified form of the screen 10 of the first embodiment. FIG. 18 shows a cross section of a modified screen 50 corresponding to the cross section of the screen 10 of the first embodiment shown in FIG. A part of a cross section passing through the point and parallel to the vertical direction (Y direction) of the screen and orthogonal to the screen surface (parallel to the Z direction) is shown enlarged.
The screen 50 of the modified form includes, in order from the image source side along the thickness direction, the light control layer 16, the bonding layer 17a, the first substrate layer 11, the first optically shaped layer 12, the reflective layer 53, and the second optically shaped layer. 54.
The reflective layer 53 is a layer having a function of reflecting light. The reflective layer 53 is formed on at least part of the first slope 121a. In FIG. 18, the reflective layer 53 is formed on the first slope 121a and not on the second slope 121b. It is good also as a form carried out.

The reflective layer 53 is preferably formed on the first slope 121a by evaporating or sputtering a metal such as aluminum, silver, or nickel, or by transferring a metal foil.
In addition, the reflective layer 53 includes particles obtained by pulverizing a silver-based paint, an ultraviolet curable resin or a thermosetting resin containing silver-based pigments, beads, or the like, metal vapor-deposited films such as silver or aluminum, or metal foil, or the like. It is also possible to apply a paint or the like containing fine flakes by various coating methods such as spray coating, die coating, screen printing, and groove filling by wiping, and then cure the coating.

The second optical shape layer 54 is provided on the rear side (−Z side) of the reflective layer 53 and the first optical shape layer 12 so as to cover them, like the second optical shape layer 14 of the embodiment. there is This second optical shape layer 54 has light absorption properties and does not have light transmission properties.
Since the second optical shape layer 54 is in contact with the second slope 121b, it absorbs external light such as sunlight and illumination light incident on the second slope 121b from the image source side, thereby improving the contrast of the image. be able to. In addition, since the second optical shape layer 54 has light absorption properties, even when a support plate (not shown) disposed on the back side of the screen 50 has light transmission properties, external light incident from the back side A decrease in image contrast can be suppressed.

Such a second optical shape layer 54 is formed of a thermosetting resin or an ultraviolet curable resin containing dark pigments or dyes such as black, beads having a light absorbing action, carbon black, etc., or a dark color such as black. It is preferable to use a water-based paint, an organic paint, or the like.
In addition, from the viewpoint of sufficiently exhibiting the light absorbing action, the protective action of the reflective layer 53, and the like, the second optical shape layer 54 is arranged in the thickness direction of the screen 50 from the point t1, which is the vertex between the unit optical shapes 121, to the rear side thereof. It is preferable to have a sufficient dimension to the surface.

The screen 50 is joined to a support plate (not shown) via a joining layer (not shown). The support plate is, for example, a plate-like member made of wood, glass, resin, or the like, and preferably does not have light transmittance. Also, an indoor wall or the like can be used as the support plate.

In addition to the above example, the second optical shape layer 54 does not have light absorption properties, and a support plate (not shown) disposed on the back side of the screen has light absorption properties ( It may be in a form that does not have light transmittance), or a second base material layer that is a sheet-like resin layer that has light absorption properties may be provided on the back side of the second optical shape layer 54. . The second optical shape layer 54 and the second substrate layer may both have light absorption properties and may not have light transmission properties.
Even in the screen 50 of such a modified form, a reflective screen 50 and an image display device capable of displaying a clear image and reducing the glare (speckle) of the image can be obtained.
Also, the screen 40 of the third embodiment may be provided with the reflective layer 53 and the second optically shaped layer 54 but not with the light control layer 30 or the like, and may be an opaque screen having no transparency.

(3) In the first to third embodiments, the light control layer 16 selectively diffuses incident light according to the incident angle in the vertical direction of the screen in a cross section parallel to the vertical direction of the screen and the thickness direction. Although not limited to this, the light control layer 16 selectively diffuses incident light according to the incident angle in the arrangement direction of the unit optical shapes 121 in a cross section parallel to the arrangement direction and thickness direction of the unit optical shapes 121. It is good also as a form which carries out. When the unit optical shapes 121 are arranged concentrically around the point C as in each embodiment, the optical performance of the light control layer 16 is also concentrically distributed. With such a configuration, the light can be diffused more effectively, and a sufficient viewing angle can be ensured for locations where the viewing angle tends to decrease, such as the left and right ends of the upper side of the screen.

In addition, in the first to third embodiments, the light control layer 16 shows an example in which the specific angle range for diffusing and transmitting incident light is constant in the cross section parallel to the vertical direction and thickness direction of the screen. However, the specific angle range may change continuously or stepwise along the vertical direction of the screen. By adopting such a form, it is possible to more effectively diffuse the light corresponding to the incident angle of the image light that changes in the vertical direction of the screen, and to display a good image.

(4) In the first to third embodiments, the light control layer 16 may transmit light incident from the rear side (−Z side) without diffusing it regardless of the incident angle. That is, the light control layer 16 may have a form that does not have the third incident angle range R3.

(5) In the first embodiment, the screen 10 is provided on the image source side (+Z side) with respect to the reflective layer 13 as a light absorption layer that partially transmits and partially absorbs incident light. A colored layer colored with a dark coloring material such as black or gray may be provided so as to have the same ratio. In the screen 10, by providing such a colored layer closer to the image source than the reflection layer 13, the light reflected at the interface with the air on the back side of the screen 10 is emitted to the image source side to form a double image. can be suppressed. In addition, by providing such a colored layer, it is possible to reduce the black brightness of the image and absorb external light from the image source side, thereby improving the contrast of the image.
For example, such a colored layer may be newly laminated on the image source side (+Z) of the light control layer 16. For example, the bonding layer 17a, the first base material layer 11, etc. It may be in a form having a function as a colored layer.
In addition, not only in the first embodiment but also in the second to fifth embodiments, the

screens

20, 40, 70, and 80 have the colored layer as described above on the image source side (+Z side) of the reflective layer 13. It is good also as a form provided.

In addition, in the first embodiment, the colored layer as described above may be provided on the back side (-Z side) of the reflective layer 13 . By providing such a colored layer on the back side of the reflective layer 13, the light reflected at the interface with the air on the back side of the screen 10 can be prevented from being emitted to the image source side and causing a double image. A clear image can be displayed. Further, by providing the colored layer on the back side of the reflective layer 13, the transparency of the screen is lowered when no image light is projected, but external light from the back side can be absorbed, resulting in a bright, high-contrast image. can be displayed. Such a colored layer may be newly laminated on the back side of the second base material layer 15. For example, the second base material layer 15 or the like contains a coloring material and functions as a colored layer. It may be in the form

Note that the above-described light absorption layer (coloring layer) is particularly arranged on the most image source side or the most rear side of the screen 10 of the first embodiment, that is, it is arranged at the interface between the screen and the air. It is more effective to
Further, in the second to fifth embodiments, the colored layer may be provided instead of the light control layer 30 .

(6) In each embodiment, the first slope 121a and the second slope 121b of the unit optical shape 121 may be, for example, a combination of a curved surface and a flat surface, or may be a bent surface.
Also, the unit optical shape 121 may be a polygonal shape formed by three or more surfaces.
In addition, although an example in which the reflective layer 13 is formed on the first slope 121a and the second slope 121b is shown, the present invention is not limited to this, and may be formed on at least a part of the first slope 121a.
In the embodiment, the first slope 121a and the second slope 121b have fine and irregular uneven shapes, but the present invention is not limited to this. It is good also as a form which has.

(7) In each embodiment, the image source LS is positioned at the center of the

screens

10, 20, 40, 70, 80 in the horizontal direction and below the screens. Instead, it may be located above the

screens

10, 20, 40, 70, 80, for example. In this case, the

screens

10, 20, 40, 70, and 80 are reversed in the vertical direction (Y direction).
In addition, the image source LS may project image light onto the

screens

10, 20, 40, 70, 80 from oblique direction light. In this case, the point C, which is the Fresnel center of the circular Fresnel lens shape of the first optically shaped layer 12, is arranged at the position of the image source LS. By adopting such a form, the position of the image source LS and the like can be freely set.

(8) In the first, third, fourth, and fifth embodiments, the

screens

10, 40, 70, and 80 are such that the first optically shaped layer 12 and the second optically shaped layer 14 have sufficient thickness, rigidity, etc. In that case, at least one of the first base material layer 11 and the second base material layer 15 may be omitted.
In addition, in each embodiment, the

screens

10, 20, 40, 70, and 80 use the light control layer 16 as the base (substrate) of the first optical shape layer 12 and do not include the first substrate layer 11 or the like. It may be in the form

(9) In the second to fourth embodiments, the light-modulating layer 30 has a light-transmissive layer on both sides (the image source side surface of the base material 31A and the back side surface of the base material 31B) via a bonding layer or the like. A configuration in which substrate layers having a high D are laminated may be used. A plate-like member made of glass is suitable for such a substrate layer. That is, it corresponds to a form in which the light control layer 30 of the embodiment is arranged inside the laminated glass, and is attached to the back side of the second base material layer 15 via the bonding layer 17c.
By forming the light modulating layer 30 in this manner, the liquid crystal material in the liquid crystal layer 36 falls in the direction of gravity at high temperatures, causing uneven distribution of the liquid crystal material, and the resulting uneven transmittance. can be reduced.
In the third embodiment, even in such a form, the distance D1 from the image source side surface of the first optical shape layer 12 to the back side surface of the light control layer 16 is the second optical shape layer 12. It is preferable that the distance D2 from the back side of the shape layer 14 to the image source side surface of the light control layer 30 (the image source side surface of the substrate 31A) is longer than the distance D2.

(10) In each embodiment, the

screens

10, 20, 40, 70, and 80 have the first optical shape layer 12 in which the unit optical shapes 121 are arranged, and the reflective layer 13 is formed along the unit optical shapes 121. However, the present invention is not limited to this. For example, the surface of the first optically shaped layer on the back side is a planar rough surface formed with fine and irregular uneven shapes. The reflective layer 13 may be formed on the rear side of the optical layer 13, and the second optical shape layer may be formed on the rear side thereof.

Although each embodiment and modification can be used in combination as appropriate, detailed description thereof will be omitted. Moreover, the present invention is not limited by the embodiments and the like described above.

1

image display device

10, 20, 40, 70, 80 screen 11 first substrate layer 12 first optical shape layer 121 unit optical shape 121a first slope 121b second slope 13 reflective layer 14 second

optical shape layer

15,25 Second substrate layer 16

Light control layer

17a, 17b,

17c Joining layer

48, 88, 89 Translucent substrate layer 30

Light control layer

31A,

31B Substrate

32A, 32B

Transparent electrode

33A, 33B Orientation layer 36 Liquid crystal layer LS Image source

Claims

A reflective screen that displays an image by reflecting at least part of image light projected from an image source,
a first optical shape layer having a first surface on which image light is incident and a second surface that intersects with the first surface, and in which a plurality of unit optical shapes that are convex on the back side are arranged;
a reflective layer formed on at least a part of the first surface of the unit optical shape and having fine and irregular unevenness on the surface thereof to diffusely reflect at least part of incident light;
It is positioned closer to the image source than the reflective layer in the thickness direction of the reflective screen, diffuses and transmits incident light from a specific angular range, and diffuses incident light from outside the specific angular range. a light control layer that transmits without
with
does not have a light diffusing layer containing light diffusing particles,
an angle α formed between the first surface of the unit optical shape and a plane parallel to the screen surface increases in one direction along the arrangement direction of the unit optical shape,
The specific angular range is defined by the image of the light control layer in a cross section passing through the center of the screen of the reflective screen in a direction parallel to the arrangement direction of the unit optical shapes and in a cross section parallel to the thickness direction of the reflective screen. The angle α is in the range of 25° or more and 55° or less on the small side with respect to a straight line perpendicular to the surface on the source side;
A reflective screen characterized by a
The reflective screen according to claim 1,
In the thickness direction of the reflective screen, the distance between the image source side surface of the first optical shape layer and the back surface side surface of the light control layer is 0.5 mm or less;
A reflective screen characterized by a
A reflective screen that displays an image by reflecting at least part of image light projected from an image source,
a first optical shape layer having a first surface on which image light is incident and a second surface that intersects with the first surface, and in which a plurality of unit optical shapes that are convex on the back side are arranged;
a reflective layer formed on at least a part of the first surface of the unit optical shape and having fine and irregular unevenness on the surface thereof to diffusely reflect at least part of incident light;
It is positioned closer to the image source than the reflective layer in the thickness direction of the reflective screen, diffuses and transmits incident light from a specific angular range, and diffuses incident light from outside the specific angular range. a light control layer that transmits without
with
does not have a light diffusing layer containing light diffusing particles,
an angle α formed between the first surface of the unit optical shape and a plane parallel to the screen surface increases in one direction along the arrangement direction of the unit optical shape,
The specific angular range is defined by the image of the light control layer in a cross section passing through the center of the screen of the reflective screen in a direction parallel to the arrangement direction of the unit optical shapes and in a cross section parallel to the thickness direction of the reflective screen. A range of 25° or more and 55° or less on the side where the angle α is small with respect to a straight line perpendicular to the surface on the source side,
In the thickness direction of the reflective screen, the distance between the image source side surface of the first optical shape layer and the back surface side surface of the light control layer is greater than 0.5 mm and less than or equal to 8 mm;
A reflective screen characterized by a
In the reflective screen according to any one of claims 1 to 3,
The reflective layer is a transflective type that reflects part of incident light and transmits part of it,
A second optical shape layer provided adjacent to the reflective layer on the back side of the reflective layer, having optical transparency, and laminated so as to fill the valleys of the adjacent unit optical shapes,
The second optically shaped layer has a flat back surface, and has a refractive index equal to or equal to that of the first optically shaped layer, or has a refractive index difference that is small enough to be considered equal.
A reflective screen characterized by a
In the reflective screen according to any one of claims 1 to 4,
The first optical shape layer has a Fresnel lens shape on the back side,
The unit optical shapes are arc-shaped when viewed in a direction orthogonal to the screen surface, and are arranged concentrically around a point located outside the display area of the reflective screen;
A reflective screen characterized by a
In the reflective screen according to any one of claims 1 to 5,
Having a light absorption layer that absorbs part of incident light and transmits part of it;
A reflective screen characterized by a
In the reflective screen according to claim 6,
The light absorption layer is provided on the back side of the reflection layer,
A reflective screen characterized by a
In the reflective screen according to claim 7,
The light absorption layer can select a state in which the absorptance for light with a large incident angle is greater than that for light with an incident angle of 0° and a state in which the difference in absorptivity of light depending on the incident angle is small. being layers,
A reflective screen characterized by a
In the reflective screen according to any one of claims 6 to 8,
The reflective layer is a transflective type that reflects part of incident light and transmits part of it,
A second optical shape layer provided adjacent to the reflective layer on the back side of the reflective layer, having optical transparency, and laminated so as to fill the valleys of the adjacent unit optical shapes,
In the thickness direction of the reflective screen, the distance from the image source side surface of the light absorption layer to the back side surface of the second optical shape layer is the distance from the back side surface of the light control layer to the first optical greater than the distance to the image source side surface of the shape layer,
A reflective screen characterized by a
a reflective screen according to any one of claims 1 to 9;
An image display device comprising: an image source that projects image light onto the reflective screen.
In the image display device according to claim 10,
the specific angle range includes a main incident angle range of image light projected by the image source;
An image display device characterized by:
A reflective screen that displays an image by reflecting at least part of image light projected from an image source,
a semi-transmissive reflective layer having a surface formed with fine and irregular unevenness, diffusely reflecting at least a portion of incident light by the unevenness, and transmitting a portion of the incident light;
a light control layer that is arranged on the back side of the reflective layer in the thickness direction of the reflective screen, absorbs part of the incident light, transmits part of it, and is capable of adjusting the transmittance;
with
not having a light diffusing layer containing light diffusing particles;
A reflective screen characterized by a
A reflective screen according to claim 12, wherein
The light control layer comprises a layer containing a liquid crystal material containing a dichroic dye;
A reflective screen characterized by a
In the reflective screen according to claim 12 or 13,
In a state where the light transmittance is high, the light modulating layer has a higher absorption rate for light with an incident angle of 40° or more than that for light with an incident angle of 0°;
A reflective screen characterized by a
In the reflective screen according to any one of claims 12 to 14,
a first optical shape layer having a first surface on which image light is incident and a second surface that intersects with the first surface, and in which a plurality of unit optical shapes that are convex on the back side are arranged;
a second optical shape layer provided adjacent to the reflective layer on the back side of the reflective layer, having optical transparency, and laminated so as to fill the valleys of the adjacent unit optical shapes;
with
The reflective layer is formed on at least part of the first surface of the unit optical shape,
The second optically shaped layer has a flat back surface, and has a refractive index equal to or equal to that of the first optically shaped layer, or has a refractive index difference that is small enough to be considered equal.
A reflective screen characterized by a
A reflective screen according to claim 15, wherein
The first optical shape layer has a Fresnel lens shape on the back side,
The unit optical shapes are arc-shaped when viewed in a direction orthogonal to the screen surface, and are arranged concentrically around a point located outside the display area of the reflective screen;
A reflective screen characterized by a
In the reflective screen according to any one of claims 12 to 16,
The light control layer is
A substrate layer with high light transmittance is laminated on the image source side or the back side, or
sandwiched between two substrate layers with high light transmittance in the thickness direction;
A reflective screen characterized by a
In the reflective screen according to any one of claims 12 to 17,
It is positioned closer to the image source than the reflective layer in the thickness direction of the reflective screen, diffuses and transmits incident light from a specific angular range, and diffuses incident light from outside the specific angular range. having a light control layer that transmits without
A reflective screen characterized by a
a reflective screen according to any one of claims 12 to 18;
An image display device comprising: an image source that projects image light onto the reflective screen.