JP6287007B2 - Reflective screen and video display system with reflective screen - Google Patents

Description

  The present invention relates to a reflective screen, and more particularly to a reflective screen that reflects and displays a projected video light and a video display system including the reflective screen.

  In recent years, a reflective layer is formed on a lens layer having a linear Fresnel lens shape or a circular Fresnel lens shape in which a plurality of unit lenses are arranged in order to display the image light projected by a short focus type image projection device satisfactorily. Various screens have been developed (for example, Patent Document 1).

  Some of these reflective screens are formed in the order of the surface layer, base material layer, lens layer, reflective layer, and backcoat layer from the image source side. During transportation, storage, etc., moisture and oxygen contained in the air permeate the back coat layer on the back side of the reflective screen, oxidize the metal (for example, aluminum) constituting the reflective layer, and reflect the reflective layer. There is a problem that the rate decreases or becomes brittle.

  The back coat layer protects the reflective layer and absorbs external light to improve the contrast of the reflective screen. The back coat layer usually contains a coloring material (for example, carbon black). When the water-based ink is applied to the surface of the reflective layer, the metal of the reflective layer may be deteriorated in the same manner as described above due to moisture and other components contained in the water-based ink. In addition, when a colored aqueous ink is applied to the surface of the reflective layer to form a backcoat layer, if the colored aqueous ink contains coarse particles or foreign matter of the coloring material, the surface of the reflective layer is damaged when the ink is applied. In some cases, the reflection layer peels off from the lens layer in combination with the deterioration of the reflection layer described above.

Japanese Patent Laid-Open No. 08-29875

  An object of the present invention is to provide a reflective screen capable of suppressing oxidation of a metal constituting the reflective layer and reducing a decrease in reflectance and peeling of the reflective layer from the lens layer. Another object of the present invention is to provide an image display system provided with the reflection screen.

The reflective screen according to the present invention includes a Fresnel lens layer having a lens surface and a non-lens surface, and a plurality of unit lenses that are convex on the back side, and provided on at least a part of the lens surface of the Fresnel lens layer. A reflective screen that reflects at least the image light projected from the image source and that can be observed, and includes at least a reflective layer that reflects light and a backcoat layer provided on the back side of the reflective portion. And
A barrier layer is provided between the reflective layer and the backcoat layer.

  In the embodiment of the present invention, the barrier layer may be made of a silicon compound selected from the group consisting of silicon oxide, silicon nitride, and silicon oxynitride.

  In an embodiment of the present invention, the barrier layer may have a thickness of 5 to 500 nm.

  In an embodiment of the present invention, the reflective layer may be made of at least one metal selected from the group consisting of aluminum, silver, and chromium.

  In the embodiment of the present invention, the back coat layer may be formed by applying and drying a water-soluble solvent containing a colorant and a binder resin.

  In the embodiment of the present invention, the back coat layer may further contain an antioxidant.

  In another aspect of the present invention, an image display system including the reflection screen and an image source that projects image light onto the reflection screen is also provided.

  According to the present invention, a reflective screen having a configuration in which a barrier layer is provided between the reflective layer and the backcoat layer allows the barrier layer to shield moisture and oxygen that enter from the back side of the reflective screen. This prevents the metal from being oxidized and suppresses a decrease in reflectance. In addition, since the barrier layer is formed, even if coarse particles or foreign matters are mixed in the colored ink when forming the backcoat layer, the coarse particles or foreign matters do not directly contact the reflective layer. Can be prevented from being scratched. As a result, the reflective layer can be prevented from deteriorating and peeling from the Fresnel lens layer.

It is a figure explaining the layer structure of one Embodiment of the reflective screen by this invention. It is a figure explaining the Fresnel lens layer which comprises a reflective screen. It is a figure explaining the layer structure of another embodiment of the reflective screen by this invention. It is a figure explaining the mode of the image light and external light which inject into the reflective screen by this invention. It is a figure which shows one Embodiment of the video display system by this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, each figure shown below including FIG. 1 is the figure shown typically, and the magnitude | size and shape of each part are exaggerated suitably for easy understanding. In addition, words such as plate, sheet, and film are used, but these are generally used in the order of thickness, plate, sheet, and film, and can be replaced as appropriate. Shall. Further, the present invention is not limited to the embodiments described below.

<Reflection screen>
FIG. 1 is a schematic cross-sectional view of a reflective screen according to the present invention. As shown in FIG. 1, the reflective screen 1 according to the present invention includes a Fresnel lens layer 13 having a lens surface 131a and a non-lens surface 131b, and a plurality of unit lenses 131 that are convex on the back side, and the Fresnel lens. A reflective layer 12 that reflects light and is provided on at least a part of the lens surface 131a of the layer 13; and a backcoat layer 10 that is provided on the back side of the reflective layer 12; And a back coat layer 10 are provided with a barrier layer 11. Further, on the image light source side of the reflective screen 1, the base material layer 14 is provided on the surface opposite to the surface on which the unit lens 131 of the Fresnel lens layer 13 is provided, and on the surface of the base material layer 14. A surface layer 15 is provided. Hereinafter, each layer which comprises the reflective screen 1 is demonstrated.

  In the base material layer 14, the surface layer 15 is integrally formed on the image source side (observer side), and the Fresnel lens layer 13 is integrally formed on the back surface side (back surface side). The base material layer 14 includes a light diffusion layer 141 and a colored layer 142. In the base material layer 14 of the present embodiment, the light diffusion layer 141 and the colored layer 142 are integrally laminated. In the present embodiment, as shown in FIG. 1, the example in which the light diffusion layer 141 is on the back side and the colored layer 142 is positioned on the image source side is shown, but the present invention is not limited thereto, and the light diffusion layer 141 is the image source. It is good also as a form which is located in the side and the colored layer 142 is located in the back side.

  The light diffusion layer 141 is a layer that contains a light transmissive resin as a base material and contains a light diffusing material. The light diffusion layer 141 has a function of widening the viewing angle and improving the in-plane uniformity of brightness.

  Examples of the resin used as a base material for the light diffusion layer 141 include PET (polyethylene terephthalate) resin, PC (polycarbonate) resin, MS (methyl methacrylate / styrene) resin, MBS (methyl methacrylate / butadiene / styrene) resin, acrylic resin, and the like. Resin, TAC (triacetyl cellulose) resin, PEN (polyethylene naphthalate) resin, or the like can be used. The thickness of the light diffusion layer 141 can be about 100 to 200 μm. In addition, as the light diffusing particles, light incident on the light diffusing layer is diffused due to the refractive index difference between the transparent resin and the light diffusing particles or due to the reflectivity of the light diffusing particles themselves. Can be used without particular limitation, and can be used as inorganic fine particles such as barium sulfate fine particles, glass fine particles, aluminum hydroxide fine particles, calcium carbonate fine particles, silica (silicon dioxide) fine particles, titanium oxide fine particles, and melamine beads. Organic fine particles such as acrylic beads, acrylic-styrene beads, polycarbonate beads, polyethylene beads, polystyrene beads, polyvinyl chloride beads, silicone beads can be used, but from the viewpoint of transparency, organic fine particles should be used. Is preferred. The particle size of the light diffusing particles is not particularly limited, but those having a particle size of about 1 to 15 μm are usually used.

  The colored layer 142 is a layer colored with a dye or pigment such as gray or black to obtain a predetermined transmittance. In the present embodiment, the colored layer 142 is located on the image source side (observer side) of the light diffusion layer 141.

  The colored layer 142 has a function of improving the contrast of an image by absorbing unnecessary external light such as illumination light incident on the reflective screen 10.

  For example, the colored layer 142 has a thickness of 30 to 3000 μm and is formed of a PET resin containing a dye or a pigment, a PC resin, an MS resin, an MBS resin, an acrylic resin, a TAC resin, a PEN resin, or the like.

  The base material layer 14 may be integrally formed by coextrusion of the light diffusion layer 141 and the colored layer 142. Alternatively, the base material layer 14 may be a single layer and may contain both a diffusing material and a colorant such as a pigment or a dye.

  Next, the Fresnel lens layer will be described with reference to FIG. FIG. 2 is a diagram illustrating the Fresnel lens layer 13 of the present embodiment. FIG. 2A shows a state in which the Fresnel lens layer 13 is observed from the front side on the back side, and the reflection layer 12 and the backcoat layer 10 are omitted for easy understanding. FIG. 2B shows a part of the cross section shown in FIG.

  The Fresnel lens layer 13 is a light-transmitting layer provided on the back side of the base material layer 14 and can convert image light into substantially parallel light directed in a substantially normal direction of the screen surface and emit it. Although it can be used without particular limitation, it is preferably a circular Fresnel lens shape having an optical center at a position decentered with respect to the center of the surface of the Fresnel lens layer 13 as shown in FIG. When the image light source is arranged on the lower side of the reflection screen, the Fresnel lens-shaped optical center C1 of the Fresnel lens layer is decentered downward (that is, on the image light source side) with respect to the surface center C2 of the Fresnel lens layer 13. Preferably it is. In FIG. 2A, the optical center C1 exists at a position outside the surface 131a, but may exist within the surface 131a. When the Fresnel lens layer 13 having the unit lens 131 with the optical center C1 decentered in this way is used, the distance between the Fresnel lens layer 13 and the image light source is short, and the incident angle of the image light is large (short focus). Even in this case, it is possible to convert the image light into substantially parallel light that is directed in a direction substantially normal to the screen surface.

  In the present embodiment, the unit lens shape of the Fresnel lens layer 13 is not limited to the circular Fresnel lens shape as shown in FIG. A plurality of linear Fresnel lens shapes arranged in the direction may be used.

  As shown in FIGS. 1 and 2B, the unit lens 131 is parallel to the direction orthogonal to the screen surface (thickness direction of the reflective screen 10) and is a cross section in a cross section parallel to the arrangement direction of the unit lenses 131. The shape is a substantially triangular shape. The unit lens 131 is convex on the back surface side, and includes a lens surface 131a and a non-lens surface 131b facing the lens surface 131a.

  When the reflective screen 1 is in use, the unit lens 131 has the lens surface 131a positioned above the non-lens surface 131b in the vertical direction with the apex t interposed therebetween. In the unit lens 131, as shown in FIG. 2B, the angle formed by the lens surface 131a and the surface parallel to the screen surface is α, and the angle formed by the non-lens surface 131b and the surface parallel to the screen surface is β (β> α).

  The arrangement pitch of the unit lenses 131 is P, and the lens height of the unit lenses 131 (the dimension from the apex t in the thickness direction of the screen to the point v that is the valley bottom between the unit lenses 131) is h.

  In order to facilitate understanding, in FIG. 1 and FIG. 2B and the like, the arrangement pitch P and the angles α and β of the unit lenses 131 are shown to be constant in the arrangement direction of the unit lenses 131. However, the unit lenses 131 of the present embodiment actually have a constant arrangement pitch P and the like, but gradually become larger as the angle α becomes farther from the optical center C1 of the Fresnel lens 13 in the arrangement direction of the unit lenses 131. .

  However, the present invention is not limited to this, and the angle α or the like may be constant, or the arrangement pitch P may gradually change along the arrangement direction of the unit lenses 131, and the pixel of the video source LS that projects the video light. It can be appropriately changed according to the size of (pixel), the projection angle of the image source LS (the incident angle of image light on the screen surface of the reflection screen 1), the screen size of the reflection screen 1, the refractive index of each layer, and the like. .

  The unit lens 131 has an example in which the cross-sectional shape shown in FIG. 2 or the like is a substantially triangular shape. However, the unit lens 131 is not limited to this. For example, the unit lens 131 has a substantially trapezoidal shape. It is good also as a form which opposes on both sides of the top surface parallel to. At this time, the top surface is preferably formed in a region that does not contribute to the reflection of the image light.

  The unit lens 131 has an example in which the lens surface 131a and the non-lens surface 131b are linear in the cross section shown in FIG. 2 and the like. However, the unit lens 131 is not limited to this example. Part of 131b may be curved. In each embodiment, the lens surface 131a and the non-lens surface 131b of the unit lens 131 are both single surfaces. However, the present invention is not limited to this. For example, at least one surface includes a plurality of surfaces. It is good also as a form comprised from.

  The Fresnel lens layer 13 can be formed by a conventionally known method. For example, an ultraviolet curable resin such as urethane acrylate or epoxy acrylate is filled in a mold for shaping the Fresnel lens shape, and a base material layer is formed thereon. 14 is provided, the substrate can be formed by an ultraviolet molding method or the like in which ultraviolet rays are irradiated from the substrate layer 14 side to cure the resin and release from the mold. In addition to the ultraviolet curable resin, other ionizing radiation curable resins such as an electron beam curable resin can also be used.

  Next, the reflective layer will be described. The reflective layer 12 is a layer having a function of reflecting light, and is formed on at least a part of the lens surface 131a. The light incident from the image light source side is internally reflected by the lens surface 131a. In the present embodiment, the reflective layer 12 is formed on the lens surface 131a as shown in FIGS. 1 and 2B, but is not formed on the non-lens surface 131b.

  The reflective layer 12 can be formed by a conventionally known method, for example, by vapor deposition of a metal having high reflectivity such as aluminum, silver, nickel, or chromium. Moreover, you may form by not only vapor deposition but sputtering, CVD, plating, gravure coating, gravure reverse coating, screen printing, the application | coating by an inkjet system. Alternatively, a foil made of a highly reflective metal such as aluminum, silver, nickel, or chromium may be transferred onto the lens surface 131a. The thickness of the reflective layer formed in this way is about 5 to 30 μm.

  Next, the barrier layer 11 will be described. The barrier layer 11 is a layer provided between the reflective layer 12 and a backcoat layer 10 to be described later, and is formed while shielding moisture and oxygen entering from the backcoat layer 10 side to the reflective layer 12 side. The surface of the reflective layer 12 (deposited film) is a layer for preventing the surface from being scratched by coarse particles or foreign matters contained in the ink when the back coat layer is formed.

  As will be described later, the conventional reflective screen is formed by applying a colored ink containing moisture to the back coat layer 10, and this moisture may denature a metal such as aluminum constituting the reflective layer. there were. Further, even after the back coat layer 10 is formed, moisture in the air is absorbed from the back side (back coat layer 10 side) of the reflective screen, and the metal of the reflective layer may be denatured. there were. For example, since aluminum hydroxide oxide obtained by hydroxylating aluminum is transparent, the reflective layer made of aluminum has a lower reflectance as the aluminum hydroxide proceeds, and may affect the optical characteristics of the reflective screen. . In the present invention, in order to solve the above problems, a barrier layer 11 capable of suppressing the transmission of moisture and oxygen is provided between the reflective layer 12 and the backcoat layer 10.

  In the present embodiment, as shown in FIGS. 1 and 2B, the barrier layer 11 is provided only on the surface of the reflective layer 12 that is formed only on the lens surface 131a and not on the non-lens surface 131b. However, as another embodiment, as shown in FIG. 3, the barrier layer 11 may be formed on the surface of the reflective layer 12 and the surface of the non-lens surface 131b. In this way, by forming the barrier layer 11 also on the surface of the non-lens surface 131b, it is possible to prevent moisture and oxygen from entering from the side surface of the reflective layer 12 and oxidizing the metal of the reflective layer 12. .

  The barrier layer 11 is a layer made of a material having a low water vapor or oxygen permeability, for example, silicon oxide, aluminum oxide, magnesium oxide, indium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, barium oxide. And oxides such as tin oxide and zinc oxide; nitrides such as silicon nitride, aluminum nitride, boron nitride and magnesium nitride; carbides such as silicon carbide; and sulfides. Moreover, you may use 2 or more types of composite_body | complex chosen from them.

Examples of composites include composite oxides using two or more oxides, composite metal oxynitrides using two or more oxides and nitrides, inorganic oxynitrides containing oxygen and nitrogen, and carbon. Examples thereof include inorganic oxide carbides, inorganic nitride carbides, and inorganic oxynitride carbides. More specifically, inorganic oxide (MO _x ), inorganic nitride (MN _y ), inorganic carbide (MC _z ), inorganic oxide carbide (MO _x C _z ), inorganic nitride carbide (MN _y C _z ), inorganic _Examples thereof include oxynitrides (MO _x N _y ) and inorganic oxynitride carbides (MO _x N _y C _z ), and preferred M is a metal element such as Si, Al, or Ti. Among these, a film made of M and Si and made of silicon oxide is preferably used because it has high transparency and good barrier properties, and silicon nitride exhibits higher barrier properties. Particularly preferred is a composite of silicon oxide and silicon nitride (inorganic oxynitride (SiO _x N _y )). When the content of silicon oxide is large, the transparency is improved, and when the content of silicon nitride is large, the barrier property is improved. Moreover, since the easy to ensure the flexibility and adhesion of the layer by the inclusion of carbon, it is also preferable to use an inorganic oxide carbide (SiO x _{C z).} In addition, examples of composite oxides using two or more oxides include MaMbO _x and MaMbMcO _x . Furthermore, examples of the composite metal oxynitride using two or more oxides and nitrides include MaMbO _x N _y , MaMbMcO _x N _{y, and the} like. Here, Ma, Mb, and Mc represent different metal elements, and examples thereof include Sn, Zn, Si, Al, and Ti. The barrier layer may contain a predetermined amount of predetermined additives and impurities in addition to the above materials.

  The thickness of the barrier layer 11 is usually 5 to 500 nm, preferably 50 to 200 nm. If the thickness of the barrier layer 4 is in the above range, the intrusion of moisture and oxygen from the back coat layer 11 side can be further shielded, and the influence of moisture and the like on the reflective layer 12 can be suppressed.

  The formation of the barrier layer 11 is not particularly limited, but a vacuum film forming method is usually used. As such a vacuum film forming method, for example, a vacuum deposition method, a sputtering method, an ion plating method, a Cat-CVD method, a plasma CVD method, an atmospheric pressure plasma CVD method, or the like may be used. Such a formation method may be selected in consideration of the type of film forming material, easiness of film formation, process efficiency, and the like.

  For example, the vacuum deposition method is a method of forming a barrier layer by heating and evaporating the material contained in the crucible by resistance heating, high-frequency induction heating, beam heating such as an electron beam or ion beam, and adhering it to the base material. It is. At that time, the heating temperature and the heating method can be changed depending on the composition of the barrier layer, and a reactive vapor deposition method that causes an oxidation reaction or the like during film formation can also be used.

  In sputtering, a target is placed in a vacuum chamber, and a high-voltage ionized rare gas element (usually argon) is collided with the target to eject atoms on the target surface and adhere to the substrate. This is a method for obtaining a barrier layer. At this time, a reactive sputtering method in which a barrier layer is formed by reacting an element ejected from the target with nitrogen or oxygen by flowing nitrogen gas or oxygen gas into the chamber may be used.

  The ion plating method is a combined technique of vacuum vapor deposition and plasma, and in principle, a gas plasma is used to form a thin film by activating some of the evaporated particles as ions or excited particles. In the ion plating method, reactive ion plating in which a reactive gas plasma is combined with evaporated particles to synthesize a compound film is effective. Since the operation is in plasma, the first condition is to obtain a stable plasma. In many cases, low-temperature plasma using weakly ionized plasma in a low gas pressure region is used. For this reason, it is preferably used when a mixture or a complex oxide is formed.

  Moreover, the plasma CVD method is a kind of chemical vapor deposition method, in which raw materials are vaporized and supplied during plasma discharge, and the gases in the system are mutually activated and radicalized by collision. This makes it possible to carry out reactions at low temperatures, which is impossible depending on the case. The substrate or the like is heated from behind by a heater, and a film is formed by a reaction during discharge between the electrodes.

  Next, the back coat layer 10 will be described. The back coat layer 10 is provided on the back side of the Fresnel lens layer 13, the reflective layer 12, and the barrier layer 11, and has a function of protecting the barrier layer 11 and the reflective layer 12 and a function of absorbing light. As shown in FIGS. 1 and 2B, the back coat layer 10 of the present embodiment covers the barrier layer 11 and the non-lens surface 131b, and is also formed on the non-lens surface 131b. Yes. When the barrier layer 11 is also provided on the surface of the non-lens surface 131b, the back coat layer 10 is provided so as to cover the entire barrier layer 11.

  The back coat layer 10 does not dissolve a dark paint such as black, a dark pigment or dye such as black, beads having a light absorption function, and a binder resin such as an acrylic resin in an appropriate solvent. It is formed by applying the dispersed coating liquid (ink) to the back side of the barrier layer formed on the lens surface of the Fresnel lens layer 13 and drying it. By providing the backcoat layer 10, light (for example, external light) incident on the non-lens surface 131 b of the Fresnel lens layer 13 can be absorbed.

  In addition to various additives (for example, a thickener, a leveling agent, etc.), you may make the coating liquid which forms the backcoat layer 10 contain antioxidant and a dampproofing agent. Thereby, the back coat layer 10 can further prevent the moisture that has entered from the back side of the reflective screen 10 from reaching the reflective layer 12 while preventing the reflective layer 12 from being oxidized. The antioxidant is added so that the mass ratio with respect to the binder resin component in the coating liquid is in the range of 1 to 3%.

  Examples of the antioxidant include 2,6-di-t-butylparacresol (DBPC), 4,4 ′ methylenebis (2,6-di-t-butylphenol), 4,4′methylenebis (6-t-butyl). -O-cresol), phenyl-α-naphthylamine, phenothiazine, P, P′-dioctyldiphenylamine, N, N′disalicylidene-1,2-diaminopropane, benzotriazole, 2 (n-dodecyldithio) benzimidazole, etc. Any one or a combination of a plurality of types of these can be used. Moreover, as a moisture-proof agent contained in the backcoat layer 11, silica gel, calcium carbonate, or the like can be used.

  Next, the surface layer 15 will be described. The surface layer 15 is a layer provided on the image source side (observer side) of the base material layer 14. In the present embodiment, the surface layer 15 is formed on the outermost surface of the reflective screen 1 on the image source side. The surface layer 15 preferably has a hard coat function for reducing scratches on the image source side surface of the reflective screen 1 and a function for reducing reflection on the screen (anti-glare function). The surface layer 15 has a thickness of about 1 to 25 μm.

  The surface layer 15 may be bonded to the base material layer 14 via an adhesive layer (not shown), and on the surface of the base material layer 14 opposite to the Fresnel lens layer 13 as described above. The surface layer 15 may be directly provided by melt extrusion molding or the like.

  Although the surface layer 15 has shown an example having a hard coat function and an antiglare function, the present invention is not limited thereto, and an antireflection function, an ultraviolet absorption function, an antifouling function, an antistatic function, etc. are appropriately selected and further provided Also good. These layers may be provided as a separate layer between the above-described surface layer 15 and the base material layer 14, or a resin having the above-described function is selected and formed as a resin for forming the surface layer 15. Also good.

  In the present embodiment, the reflective screen 1 is configured from the back side in the order of the backcoat layer 10, the barrier layer 11, the reflective layer 12, the Fresnel lens layer 13, the base material layer 14, and the surface layer 15. However, the present invention is not limited to this. For example, an anisotropic diffusion layer (not shown) that diffuses light in the horizontal direction rather than the vertical direction may be formed between the Fresnel lens layer 13 and the base material layer 14.

  The state of the image light and the external light incident on the reflection screen 1 of the present embodiment will be described. FIG. 4 is a diagram for explaining the appearance of image light and external light incident on the reflection screen 1. In FIG. 4, for easy understanding, the refractive index difference of each layer of the reflective screen 1, the diffusion action of the light diffusion layer 141, and the like are omitted.

  As shown in FIG. 4, most of the image light L1 projected from the image source LS enters from below the reflection screen 10, passes through the surface layer 15 and the base material layer 14, and is a unit lens of the Fresnel lens layer 13. Incident on 131.

  Then, the image light L1 enters the lens surface 131a, is reflected by the reflective layer 12, and exits from the reflective screen 10 toward the viewer O side. Note that the angle β (see FIG. 4B) is larger than the incident angle of the image light L1 at each point in the vertical direction of the screen of the reflection screen 1 when the image light L1 is projected from below the reflection screen 1. The light L1 does not directly enter the non-lens surface 131b, and the non-lens surface 131b does not affect the reflection of the video light L1.

  On the other hand, unnecessary external lights G1 and G2 such as illumination light are incident mainly from above the reflection screen 1 and transmitted through the surface layer 15 and the base material layer 14 as shown in FIG. The light enters the lens 131. A part of the external light G1 enters the non-lens surface 131b and is absorbed by the backcoat layer 10. Further, a part of the external light G2 is reflected by the lens surface 131a and mainly goes to the lower side of the reflection screen 1, so that it does not reach the observer O side directly, and even when it reaches, Significantly less than the image light L1. Therefore, the reflective screen 1 can suppress a decrease in the contrast of the image due to the external lights G1 and G2.

<Video display system>
FIG. 5 is a diagram illustrating the video display system 100 of the present embodiment. FIG. 5A is a perspective view of the video display system 100, and FIG. 5B is a side view of the video display system 100.

  The video display system 100 includes a reflective screen 1, a video source LS, and the like. The video display system 100 according to the present embodiment is a general video display system in which the video light L projected from the video source LS is reflected by the reflective screen 1 and video is displayed on the screen.

  The video display system 100 can be used as, for example, a front projection television system. Note that the video display system 100 may be an interactive board system including a reflection screen 1, a video source LS, a position detection unit that detects the position of the input unit on the observation screen of the reflection screen, a personal computer, and the like.

  The video source LS is a device that projects the video light L onto the reflection screen 1, and a general-purpose short focus projector or the like can be used. When the image source LS is viewed from the normal direction (the normal direction of the screen surface) of the reflection screen 10 in the use state, the image source LS is centered in the left-right direction of the reflection screen 1 and It is arranged at a position below the screen (display area). The screen surface refers to a surface that is the planar direction of the reflection screen when viewed as the entire reflection screen.

  The video source LS can project the video light L from a position where the distance from the reflective screen 1 in a direction orthogonal to the screen of the reflective screen 10 (thickness direction of the reflective screen 1) is much closer than that of a conventional general-purpose projector. . That is, the image source LS has a shorter projection distance to the reflection screen 1 and a larger incident angle of the image light L with respect to the reflection screen 1 than a conventional general-purpose projector.

  The reflection screen 1 is a screen that displays the image by reflecting the image light L projected by the image source LS toward the observer O side. In the state of use, the observation screen of the reflection screen 1 has a planar shape. When viewed from the observer O side, the observation screen has a substantially rectangular shape in which the long side direction is the horizontal direction of the screen.

  In the following description, the screen vertical direction, the screen horizontal direction, and the thickness direction are the screen vertical direction (vertical direction) and the screen horizontal direction (horizontal direction) when the reflective screen 1 is used unless otherwise specified. The thickness direction (depth direction) is assumed.

  The reflective screen 1 is provided with a flat support plate 16 on the back side thereof via a bonding layer (not shown) made of an adhesive material or the like, and the support plate 16 maintains its flatness. . The reflective screen 1 has a large screen (display area) such as a diagonal of 80 inches or 100 inches.

  The bonding layer (not shown) made of an adhesive or the like may contain the above-described antioxidant or moisture-proofing agent. Even in this case, since the antioxidant and the moisture-proofing agent are contained in the bonding layer provided on the back side of the Fresnel lens layer 13, moisture in the air is absorbed from the outer peripheral side of the reflective screen, the back side, and the like. Even if it did, it can suppress the oxidation of the metal contained in the reflection layer 12, and can suppress that the reflection layer 12 peels from the lens surface 131a.

  The reflective screen 1 may further include a highly rigid substrate layer (not shown) made of glass or resin in order to maintain the flatness of the screen of the reflective screen 1. Further, as shown in FIG. 5, the reflective screen 1 is bonded to the support plate 16 provided on the back side thereof via a bonding layer, and an example of a substantially flat plate shape is shown. However, the present invention is not limited thereto. For example, the support plate 16 may not be provided, and the reflective screen may be bonded to the wall surface or the like via the bonding layer, or may be fixed to the wall surface with the support plate 16 bonded to the back surface, It is good also as a form etc. which are suspended on a wall surface by a supporting member. Although the example in which the reflecting screen 1 has a substantially flat plate shape at the time of use and when not in use is shown, the present invention is not limited to this.

  Examples The present invention will be described in more detail with reference to examples, but the present invention is not limited to the contents of these examples.

<Production of reflection screen>
Example 1
An acrylic resin containing acrylic-styrene resin beads was used as the light diffusion layer forming resin composition, and an acrylic resin containing a black dye was used as the colored layer forming resin composition. Both resin compositions are put into a co-extrusion molding machine, and a laminate is formed by batch extrusion so that the width is 1500 mm and the total thickness is 1.5 mm, and an epoxy resin composition is formed on the surface of the colored layer of the laminate. After the product was applied by a roll coating method, a hard coat layer having a thickness of 25 μm was formed by irradiating with 1000 mJ ultraviolet rays. After cutting the obtained laminate into single sheets, the mold for Fresnel lens cut into a circular shape is filled with an ultraviolet curable resin, the light diffusion layer side of the cut laminate is applied to the mold, and ultraviolet rays are applied. To form a Fresnel lens layer. After removing the uncured surplus resin, a reflective film made of aluminum having a thickness of 70 nm was formed on the surface of the Fresnel lens layer by a vacuum film forming method. Next, a barrier layer made of silicon nitric oxide was formed to a thickness of 100 nm on the surface of the reflective film by sputtering while flowing oxygen, argon, and nitrogen. Subsequently, a black paint was applied by roll coating so as to cover the surface of the formed barrier layer to form a back coat layer, thereby producing a reflective screen.

Example 2
In Example 1, except that a silicon oxide film was formed without introducing nitrogen when forming the barrier layer, and then the barrier layer was formed by performing a heat treatment at 50 ° C. for 24 hours under atmospheric pressure. A reflective screen was formed as in 1.

Comparative Example 1
In Example 1, a reflective screen was produced in the same manner as in Example 1 except that the back coat layer was formed directly on the surface of the reflective layer without forming the barrier layer.

<Evaluation of reflective screen>
The reflectance immediately after the production of the reflective screen was measured using a test piece obtained by cutting out the central part of the reflective screen of Examples and Comparative Examples obtained as described above into a size of 60 mm × 60 mm. The reflectance was measured using a reflectometer (HR-100, manufactured by Murakami Color Co., Ltd.) under the conditions of incident angle / reflecting angle = 45 ° / 45 °.

  Next, the test piece was cured for 1000 hours in an environment of 40 ° C. and a humidity of 90 RH, and then further cured for 24 hours in a room temperature environment of room temperature (about 25 ° C.) and a humidity of about 40 RH%. Measurement was performed in the same manner as described above. The difference from the reflectance immediately after the production of the reflective screen was taken as the reflectance displacement. The evaluation results were as shown in Table 1 below.

  In order to suppress a decrease in PG (dark room white luminance × π / projector illuminance) value, which is an index representing the front luminance of the reflecting screen, to 5% or less, the reflectance displacement of the reflecting screen is set to 1.0% or less. Although it is said that it is necessary, in the reflective screen according to the present invention, as shown in the above evaluation results, a barrier layer is provided between the reflective layer and the back coat layer, so that the reflectance displacement is 1.0%. We were able to:

DESCRIPTION OF SYMBOLS 1 Reflective screen 10 Backcoat layer 11 Barrier layer 12 Reflective layer 13 Lens layer 131a Lens surface 131b Non-lens surface 14 Base material layer 141 Light-diffusion layer 142 Colored layer
15 Surface layer 16 Support plate 100 Video display system LS Video source

Claims (7)

A Fresnel lens layer having a lens surface and a non-lens surface, and a plurality of unit lenses that are convex on the back side, and a reflective layer that reflects light, provided on at least a part of the lens surface of the Fresnel lens layer And a back coat layer provided on the back side of the reflective layer , and a reflective screen that reflects the image light projected from the image source and displays it in an observable manner,
A reflective screen, wherein a barrier layer is provided between the reflective layer and the backcoat layer.   The reflective screen according to claim 1, wherein the barrier layer is made of a silicon compound selected from the group consisting of silicon oxide, silicon nitride, and silicon oxynitride.   The reflective screen according to claim 1, wherein the barrier layer has a thickness of 5 to 500 nm.   4. The reflective screen according to claim 1, wherein the reflective layer is made of at least one metal selected from the group consisting of aluminum, silver, nickel, and chromium.   The reflective screen according to claim 1, wherein the back coat layer is formed by applying and drying a water-soluble solvent containing a colorant and a binder resin.   The reflective screen according to claim 1, wherein the back coat layer further comprises an antioxidant. A reflective screen according to any one of claims 1 to 6;
An image source for projecting image light onto the reflective screen;
A video display system comprising:

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