JP2010122574A - Projection type image display device and projection optical system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve miniaturization in a height direction of an entire projection type image display device by appropriately arranging a plane reflection surface in a projection optical system. <P>SOLUTION: The projection optical system which magnifies and projects image information on a primary image surface modulated by an image modulation element to a screen being a secondary image surface includes a first optical system L1 having positive refractive power and a second optical system L2 having a concave reflection surface. The first optical system L1 has an eleventh optical system L11 having positive refractive power on a side of the primary image surface, a twelfth optical system L12 having negative refractive power on a side nearer to the secondary image surface than the eleventh optical system L11, and a first plane reflection surface M1 arranged between them. A y-axis rotational angle β1 of the first plane reflection surface M1 is set to 30°<¾β1¾<65°, and an x-axis rotational angle α1 is set to 3°<α1<15°. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a projection type image display apparatus that displays a projection image on a screen and a projection optical system used in the projection type image display apparatus.

  In recent years, a liquid crystal projector device has been widely known as a projection-type image display device that displays a projected image on a screen. In particular, recently, the demand for an ultra-wide-angle front projection type liquid crystal projector device capable of displaying a large screen while reducing the projection space is increasing. This is because if a super-wide-angle front projection type liquid crystal projector device is used, it is possible to project a large screen in a limited space by driving it obliquely and at a wide angle with respect to the screen.

As a projection-type liquid crystal projector device, for example, an apparatus including a relay optical system having a zooming function and an aspheric reflection mirror that magnifies and projects an imaging screen of the relay optical system is known (for example, , See Patent Document 1).
However, in the configuration using such a large curved reflecting surface (aspheric reflecting mirror), the height direction dimension becomes large when considering the entire apparatus including the substrate for driving the image modulation element and the cooling mechanism. Tend to.
On the other hand, for the projection type liquid crystal projector device, two plane mirrors are arranged between the first optical system and the second optical system constituting the projection optical system, and the size in the depth direction is reduced. It has been proposed to suppress (see, for example, Patent Document 2).
In addition, a single plane mirror is arranged inside the first optical system constituting the projection optical system, and 1 is also provided between the first optical system and the second optical system constituting the projection optical system. It has been proposed to reduce the size of the projection optical system by arranging a single plane mirror (see, for example, Patent Document 3).

JP 2007-11248 A International Publication No. 06-043666 Pamphlet JP 2008-165202 A

However, the above-described prior art has the following drawbacks.
For example, the configuration disclosed in Patent Document 2 is suitable for an optical system that reduces only the depth direction, such as a thin projection television, but particularly for reducing the entire optical system including the height direction. There is no mirror arrangement.
In the configuration disclosed in Patent Document 3, there is a problem in the positional relationship between the concave reflecting surface and the image modulation element. In the case of this configuration, the arrangement direction of the illumination optical system increases in the depth direction of the optical system. For this reason, the arrangement of mirrors for reducing the overall size is not provided. Furthermore, with regard to the height direction, there is a risk of increasing the size in the height direction when considering a drive substrate that drives the image modulation element and a system that cools heat generated from the image modulation element, the light source, and the like. .
That is, in the above-described conventional technology, it is not always possible to achieve downsizing in the height direction of the entire apparatus.

  Accordingly, an object of the present invention is to provide a projection-type image display apparatus and a projection optical system that can realize downsizing in the height direction of the entire apparatus by appropriately arranging the plane reflecting surfaces. To do.

  The present invention is a projection-type image display device devised to achieve the above object, and illumination that uniformly irradiates a light source and a light beam emitted from the light source onto a surface of an image modulation element serving as a primary image surface. An optical system, and a projection optical system that enlarges and projects the image information of the primary image plane modulated by the image modulation element onto a screen serving as a secondary image plane, and the projection optical system has a positive refractive power A first optical system having a concave reflecting surface, and the first optical system has an eleventh optical system having a positive refractive power on the primary image surface side, and A twelfth optical system having a negative refractive power on the side of the secondary image plane from the eleventh optical system, and a first planar reflecting surface disposed between the eleventh optical system and the twelfth optical system. And the y-axis rotation angle β1 of the first flat reflecting surface is 30 ° <| β1 | <65 °, Angle [alpha] 1 is 3 ° <α1 <15 °.

In the projection type image display apparatus having the above-described configuration, the y-axis rotation angle β1 of the first planar reflecting surface disposed between the eleventh optical system and the twelfth optical system is 30 ° <| β1 | <65 °. The x-axis rotation angle α1 is 3 ° <α1 <15 °.
Here, the y-axis rotation angle means a rotation angle around the y-axis. The x-axis rotation angle refers to a rotation angle around the x-axis. The y-axis and the x-axis are reference axes in the plane when the installation surface of the projection type image display apparatus is the xy plane.
Thus, the first planar reflecting surface has a rotation angle with respect to both the y-axis and the x-axis. Accordingly, the size in the z-axis direction perpendicular to the xy plane, that is, the size in the height direction of the projection-type image display device is smaller than when only one of the y-axis and the x-axis has a rotation angle. It will be suppressed.

  According to the present invention, by configuring the projection optical system including the first planar reflection surface having the rotation angle in both the y-axis and the x-axis, and passing through the reflection on the first planar reflection surface, It is possible to reduce the size of the projection type image display device in the height direction. That is, it is possible to reduce the size of the entire apparatus in the height direction by appropriately arranging the first flat reflecting surface.

  Hereinafter, a projection type image display apparatus and a projection optical system according to the present invention will be described with reference to the drawings.

[Outline of projection type image display device]
First, an outline of a projection type image display device will be briefly described by taking a liquid crystal projector device as an example.
The liquid crystal projector device modulates light emitted from a light source such as a high-pressure mercury lamp with a liquid crystal display element, which is an image modulation element, to form an optical image according to a video signal, and the optical image is projected with a projection optical system. It is configured to be enlarged and projected and displayed on the screen. As such a liquid crystal projector device, a so-called three-plate type having panel-like liquid crystal display elements corresponding to R (red), G (green) and B (blue) colors is widely known. . In the following description, the panel-like liquid crystal display element is also simply referred to as “liquid crystal panel”.
By the way, in the liquid crystal projector described here, it is assumed that the projection optical system corresponds to an ultra-wide angle of, for example, a half field angle of around 70 °.

For example, the following matters can be cited as advantages of dealing with the ultra-wide angle.
1 to 5 are explanatory diagrams illustrating advantages of a liquid crystal projector apparatus that supports ultra-wide angles.
The ultra-wide-angle support is safe because (1) light from the liquid crystal projector device does not directly enter the human eye (see, for example, FIG. 1). (2) Since no shadow appears on the screen, an efficient presentation can be performed (see, for example, FIG. 1). (3) Since the installation space is narrow, the installation can be performed without worrying about the obstacle on the ceiling (see, for example, FIG. 2). (4) Since it can be projected on a wall, maintenance is easy. Further, since the distance between the personal computer (PC) and the audiovisual equipment (AV equipment) is shortened, the cable can be easily routed (see, for example, FIG. 3). (5) The degree of freedom for setting up a meeting space or a classroom or conference room is increased (see, for example, FIG. 4). (6) Projection on a table can also be performed (for example, see FIG. 5).
The widespread use of interactive whiteboards is one factor that has increased the demand for ultra-wide-angle LCD projectors. Not only at schools and workplaces, but also in the field of digital signage (electronic advertising), Such a liquid crystal projector device is used. Electronic blackboards are also products in LCD (Liquid Crystal Display) and PDP (Plasma Display Panel), but in comparison with these, the blackboard is a system that enlarges and projects a liquid crystal panel of about 1 inch. Can be provided.

[Schematic configuration example of a projection-type image display device]
Next, a schematic configuration of a super wide-angle compatible liquid crystal projector device will be described.
FIG. 6 is an explanatory diagram showing a schematic configuration example of the liquid crystal projector apparatus.
As illustrated, the liquid crystal projector device includes a light source 1, an illumination optical system 2, and a projection optical system 3 in the casing.

FIG. 7 is an explanatory diagram illustrating a schematic configuration example of the light source 1 and the illumination optical system 2.
The light source 1 is composed of a high-pressure mercury lamp, for example, and emits a light beam to the illumination optical system 2.
The illumination optical system 2 uniformly irradiates the light beam emitted from the light source 1 onto the surface of the image modulation element (liquid crystal panel) serving as the primary image plane. More specifically, in the illumination optical system 2, the light beam from the light source 1 passes through the first and second fly-eye lenses FL, the polarization conversion element PS, and the condenser lens L. Then, after passing through these, each color component light of RGB is separated by a dichroic mirror DM that reflects only light in a specific wavelength band. Each color component light of RGB is incident on a liquid crystal panel P provided corresponding to each color of RGB while using a total reflection mirror M, a lens L, and the like. Then, after the light modulation according to the video signal is performed in each liquid crystal panel P, the light-modulated color component lights are combined by the dichroic prism PP and emitted toward the projection optical system 3. It has become.
Here, the illumination optical system 2 configured using a transmissive liquid crystal panel is taken as an example, but the illumination optical system 2 can also be configured using a reflective liquid crystal panel. In addition, a digital micromirror device (DMD) or the like can be used as the image modulation element. Furthermore, instead of the dichroic prism PP, a polarization beam splitter (PBS), a color synthesis prism that synthesizes RGB video signals, a TIR (Total Internal Reflection) prism, or the like may be used.

  The projection optical system 3 receives the light emitted from the illumination optical system 2 to expand the image information of the primary image surface modulated by the liquid crystal panel P of the illumination optical system 2 onto the screen that becomes the secondary image surface. Project.

[Example of configuration of projection optical system]
The liquid crystal projector described here is characterized by the projection optical system 3.
Hereinafter, the configuration of the projection optical system 3 will be described in order by taking the first to sixth embodiments as examples.

<First Embodiment>
FIG. 8 is an optical path diagram illustrating a schematic configuration example of the projection optical system according to the first embodiment. In the illustrated example, the optical path at the reference projection distance is shown.
As illustrated, the projection optical system 3 includes a first optical system L1 having a positive refractive power and a second optical system L2 having a concave reflecting surface. Here, the refractive power refers to the degree of refraction of an optical system (targeted to rotate about an axis) such as a lens.
The first optical system L1 has a common optical axis having a rotationally symmetric surface for all optical components constituting the first optical system L1.
The second optical system L2 is formed of a rotationally symmetric aspherical surface and has the same optical axis as that of the first optical system L1.
And by having such 1st optical system L1 and 2nd optical system L2, the projection optical system 3 is comprised so that expansion projection may be carried out from the primary image surface of a reduction side to the secondary image surface of an expansion side. ing. That is, the image information of the primary image plane modulated by the liquid crystal panel P of the illumination optical system 2 and synthesized by the dichroic prism PP is enlarged and projected onto the screen that becomes the secondary image plane.

In the projection optical system 3 having such a configuration, the first optical system L1 includes an eleventh optical system L11 having a positive refractive power and a twelfth optical system L12 having a negative refractive power from the primary image plane side. And are arranged. The light beam emitted from the first optical system L1 once forms an intermediate image IM with the second optical system L2, and then enters the second optical system L2.
In addition, in M1, M2, and M3 shown in the figure, a first plane reflection surface, a second plane reflection surface, and a third plane reflection surface are arranged, respectively, but in this figure, they are dummy surfaces for convenience. .

FIG. 9 is an explanatory diagram illustrating a configuration example of a main part of the projection optical system according to the first embodiment. In the illustrated example, a lens cross section of the first optical system L1 at the time of short-distance projection is shown.
As shown in the figure, the first optical system L1 has functions as a screen shift function SF, a magnification function MF, and a floating function FF. In addition, S shown in the figure represents an aperture stop.

The screen shift function SF is a function for moving the image formation position on the screen that becomes the secondary image plane. In order to realize the screen shift function SF, in the first optical system L1, some optical components constituting the first optical system L1 move in a direction substantially perpendicular to the optical axis of the first optical system L1. It is configured as follows. More specifically, the eleventh optical system L11 corresponding to some optical components constituting the first optical system L1 moves in a direction substantially perpendicular to the optical axis.
The mechanism for moving the eleventh optical system L11 is not particularly limited as long as it is realized using a known technique.

As described above, by moving some of the optical components constituting the first optical system L1 (specifically, the eleventh optical system L11) substantially perpendicularly to the optical axis, the secondary image plane is connected. The first optical system L1 can have a screen shift function SF for moving the image position.
When moving in a substantially vertical direction, any optical component may be moved as long as the screen can be shifted and the occurrence of decentration aberration is small. That is, it is not always necessary to move the eleventh optical system L11, and the twelfth optical system L12 may be moved, or one optical component constituting these may be moved, which is optimal from the viewpoint of the desired amount of movement and cost. A suitable moving group may be selected.
That is, the screen shift function SF is realized by moving not only all of the optical components constituting the first optical system L1 but also a part thereof. Accordingly, the number of parts to be moved is smaller and the size is smaller than when all the optical parts constituting the first optical system L1 are moved or when the image modulation element P is moved. The screen shift function SF can be realized with a simple configuration.

  For some optical components (specifically, the eleventh optical system L11) to be moved to realize the screen shift function SF, the refractive power φs of the some optical components and the first at the time of reference projection. It is desirable that the refractive power φ1 of the optical system L1 satisfies the following conditional expression (1).

  0.2 <| φs / φ1 | <1.2 (1)

  The above conditional expression (1) appropriately defines the refractive power of the moving group that realizes the screen shift function SF. That is, when the lower limit specified in the conditional expression (1) is not reached, the occurrence of decentration aberration is reduced, and the screen shift amount is also reduced at the same time. In addition, when the upper limit specified in the conditional expression (1) is exceeded, the occurrence of decentration aberration due to movement increases, resulting in deterioration of optical performance.

The scaling function MF is a function that scales an image on a screen serving as a secondary image plane. In order to realize the zooming function MF, in the first optical system L1, the eleventh optical system L11 includes a plurality of lens groups, and at least one lens group having a positive refractive power is included in the first optical system L1. It is configured to move in a direction along the optical axis of the optical system L1. In the figure, the most enlarged side is “enlarged” and the most reduced side is “reduced”.
The mechanism for moving at least one lens group having a positive refractive power is not particularly limited as long as it is realized using a known technique.

  As described above, by moving at least one lens group having a positive refractive power among the plurality of lens groups in the eleventh optical system L11 in the direction along the optical axis, the image on the secondary image plane is scaled. The first optical system L1 can be provided with a zooming function MF that performs this.

  For the lens group to be moved to realize the zoom function MF, the refractive power φm of the lens group having the largest moving amount and the refractive power φ1 of the first optical system at the time of reference projection are expressed by the following conditional expression ( It is desirable to satisfy 1).

  0.2 <| φm / φ1 | <0.9 (2)

  The above conditional expression (2) appropriately defines the refractive power of the moving group that realizes the zooming function MF. That is, when the lower limit specified in the conditional expression (2) is not satisfied, the movement amount increases. Further, when the upper limit specified in the conditional expression (2) is exceeded, the amount of aberration such as curvature of field increases, resulting in deterioration of optical performance.

  By the way, when it is desired to configure the zooming function MF with a higher zooming ratio, the following may be considered. That is, the eleventh optical system L11 is arranged from the primary image plane side with the 11a group having positive refractive power, the 11b group having positive refractive power, the 11c group having negative refractive power, and the positive It consists of four lens groups of the 11d group having refracting power. Then, at least two of the 11b and 11d groups are moved to the primary image plane side to increase the enlargement magnification, and are moved to the intermediate image side to reduce the enlargement magnification. Here, making the 11c group a moving group is also effective in increasing the zoom ratio. Here, the zoom ratio is obtained by dividing the focal length of the entire system on the most reduction side by the focal length of the entire system on the most enlargement side.

The floating function FF is a function for correcting optical performance such as image formation performance and image distortion during focusing from short distance projection to long distance projection. In order to realize this floating function FF, in the first optical system L1, the twelfth optical system L12 includes a twelfth group L12a and a twelfth group L12b. The twelfth group L12a has a negative refracting power as a whole because the surface closest to the primary image surface is formed as a convex surface. On the other hand, the twelfth group L12b is composed of a positive meniscus lens having a convex surface on the intermediate image side. The twelfth optical system L12 including the twelfth lens group L12a and the twelfth lens group L12b is configured such that the twelfth lens group L12b is the primary image plane from the intermediate image side during focusing from short distance projection to long distance projection. It is configured to move on the optical axis to the side. In the figure, “near” is the moving direction during short-distance projection, and “far” is the moving direction during long-distance projection.
The mechanism for moving the 12th group L12b is not particularly limited as long as it is realized using a known technique.

Unlike the vicinity of the stop S, the light beam transmitted through the twelfth optical system L12 can easily separate any light beam on the primary image plane. Therefore, a floating function FF that corrects the optical performance of field curvature and distortion is realized by slightly changing the light beam angle when focusing from short distance projection to long distance projection. It becomes possible.
Specifically, as described above, the twelfth optical system L12 having negative refractive power as a whole includes the twelfth group L12a and the twelfth group L12b. Then, at the time of focusing from the short distance projection to the long distance projection, the 12th group L12b composed of the positive meniscus lens is brought closer to the 12th group L12a arranged on the primary image plane side. As a result, the principal point position on the intermediate image side of the twelfth optical system L12 can be brought closer to the second optical system L2 without degrading the optical performance, and thus focusing during long distance projection becomes possible. .

  Regarding the 12th group L12a and the 12th group L12b for realizing the floating function FF, it is desirable to satisfy the following conditional expressions (3) and (4). That is, the refractive power φ12a of the twelfth group L12a, the refractive power φ12a of the twelfth group L12b, and the refractive power φ12 of the twelfth optical system L12 at the time of standard projection satisfy the following conditional expressions (3) and (4). Try to meet.

0.2 <| φ12b / φ12 | <3.0 (3)
0.2 <| φ12b / φ12a | <1.0 (4)

The above conditional expressions (3) and (4) appropriately define the refractive powers of the 12a group L12a and the 12b group L12b that realize the floating function FF.
That is, when the lower limit specified in the conditional expression (3) is not satisfied, the amount of movement at the time of floating increases, resulting in an increase in size. On the other hand, when the upper limit specified in the conditional expression (3) is exceeded, the amount of movement decreases, but the refractive power of the positive meniscus lens increases, so that the change in the ray angle increases and the optical performance deteriorates rapidly. Occurs.
Further, when the lower limit specified in the conditional expression (4) is not satisfied, the floating cannot be performed in a long projection distance range. On the other hand, when the upper limit specified in the conditional expression (4) is exceeded, the change in the light beam angle by the 12th group L12a becomes large, and the optical performance deteriorates rapidly.

  Furthermore, it is desirable that the following conditional expression (5) is satisfied for the 12a group L12a and the 12b group L12b for realizing the floating function FF. That is, the movement amount M12a when the 12a group L12a is floating and the movement amount M12b when the 12b group L12b is floating satisfy the following conditional expression (5).

  1.5 <M12b / M12a <7.0 (5)

  The above conditional expression (5) appropriately defines the movement amount ratio of the 12a group L12a and the 12b group L12b for realizing the floating function FF. That is, when the lower limit specified in the conditional expression (5) is not satisfied, floating cannot be performed in a long projection distance range. Further, when the upper limit specified in the conditional expression (5) is exceeded, the change in the light beam angle by the 12th group L12a becomes large, and the optical performance deteriorates rapidly. In other words, if the conditional expression (5) is satisfied, the optical performance can be corrected in a long projection distance range.

  With respect to the first optical system L1 configured as described above, the second optical system L2 disposed on the secondary image plane side with respect to the first optical system L1 has a rotationally symmetric aspherical surface as described above. And has the same optical axis as that of the first optical system L1. In other words, the concave reflecting surface constituting the second optical system L2 has a rotationally symmetric aspherical shape having an optical axis common to the first optical system L1. Therefore, by arranging such a second optical system L2, it is possible to appropriately correct surface curvature and distortion.

  For the projection optical system 3 configured as described above, the maximum effective diameter DM of the largest curved reflecting surface constituting the projection optical system 3 and the maximum height Dy of the primary image plane are as follows. It is assumed that conditional expression (6) is satisfied.

  3 <DM / Dy <30 (6)

The above conditional expression (6) appropriately defines the size ratio in the height direction between the maximum curved reflection surface and the primary image surface in the projection optical system 3. That is, when the lower limit specified in the conditional expression (6) is not satisfied, the screen shift function (for example, see the figure ☆) that shifts the entire optical system including the mechanism can sufficiently cope. There is little need for the shift function SF. Moreover, when the upper limit prescribed | regulated to conditional expression (6) is exceeded, there exists a possibility that the whole projection optical system may enlarge, and it may raise a cost.
Here, the case where each optical system constituting the projection optical system 3 has a concave reflecting surface and a common optical axis is taken as an example, but any optical system satisfying conditional expression (6) can be used. Such an optical system can be applied. That is, if it is a projection optical system that performs enlarged projection from the primary image surface on the reduction side to the secondary image surface on the enlargement side, it can be applied to the following optical system. Specifically, in an optical system in which an optical component that is closest to the secondary image plane and is configured by a curved surface is configured by a reflection surface, one part of the optical component that constitutes the projection optical system is approximately By decentering in parallel, the secondary image plane has a function of shifting the screen. Further, a part of the optical components constituting the projection optical system moves substantially perpendicularly to the primary image plane so as to have a scaling function for scaling the image on the secondary image plane. Even if the projection optical system has such a configuration, as long as conditional expression (6) is satisfied, only a single optical component can be moved to realize a screen shift function and a zoom function with a small and inexpensive configuration. You can get it.

  Here, the projection optical system 3 configured as described above will be briefly described below with specific numerical examples.

  FIG. 10 is a lateral aberration diagram by the projection optical system in the first embodiment. In the figure, one scale is one dot size when one dot size is enlarged and projected on the screen. The solid line is 546.1 nm, the dotted line is 620 nm, and the dashed line is 460 nm. The lateral aberration diagram shown here is a lateral aberration diagram when moved in the y direction. Of course, the moving direction is not limited to the y direction, and may be any direction as long as it is perpendicular to the optical axis.

  FIG. 11 is an explanatory diagram of a specific example of lens data of the projection optical system according to the first embodiment. In the figure, * indicates a surface having an aspherical surface, and follows the following equation (7). In addition, the circles are dummy surfaces, and the first and second flat reflecting surfaces are arranged respectively. r is the radius of curvature, d is the distance and the core thickness of the lens, nd is the refractive index at the d line (587.56 nm), and νd is the Abbe number at the d line. Further, the lens group grouped by {is a lens group related to the floating function FF, the zoom function MF, and the screen shift function SF. Further, di is a lens interval that varies when the floating function FF and the magnification function MF are realized.

  FIG. 12 shows a specific example of the numerical aperture NA on the primary image plane side, the maximum half angle of view ω at the reference projection distance, and the maximum primary image plane height y in the first embodiment. It is explanatory drawing.

FIG. 13A is an explanatory diagram illustrating a specific example of a lens group having the screen shift function SF and a movement amount in the projection optical system according to the first embodiment.
FIGS. 13B and 13C are explanatory diagrams showing specific examples of lens intervals related to the floating function FF and the magnification function MF in the projection optical system according to the first embodiment. The numerical values in the figure correspond to di in FIG. Here, fl is the focal length, and β is the magnification.

  FIG. 14 is an explanatory diagram of a specific example of an aspheric coefficient corresponding to the projection optical system according to the first embodiment. The aspheric coefficient in the example corresponds to the above equation (7).

  FIG. 15 is an explanatory diagram illustrating a specific example of the image modulation element according to the first embodiment. The one dot size in the lateral aberration of FIG. 10 described above indicates the size described here.

FIG. 16 is an explanatory diagram showing a TV distortion state when the image modulation element shown in FIG. 15 is enlarged and projected onto the secondary image plane using the projection optical system according to the first embodiment.
FIG. 17 shows the amount of change in diagonal size, image distortion, and the like when the image modulation element shown in FIG. 15 is enlarged and projected onto the secondary image plane using the projection optical system in the first embodiment. It is explanatory drawing which shows a specific example.
FIG. 18 is an explanatory diagram showing a specific example of a calculation formula based on obtaining the change amount and the like shown in FIG.

  FIG. 19 is an explanatory diagram illustrating an example of specific numerical values of the conditional expressions (1) to (6) in the projection optical system according to the first embodiment.

  According to the projection optical system 3 specified by the specific numerical examples as described above, as the screen shift function SF, the entire eleventh optical system L11 which is a part of the first optical system L1 is replaced with the optical axis. Moving the screen vertically by 0.4 mm enables a screen shift of about ± 5%. Further, as the magnification changing function MF, by moving one group constituting the eleventh optical system L11 on the optical axis, an enlargement magnification of about ± 0.35% is changed. In addition, when the 12a group L12a and the 12b group L12b constituting the twelfth optical system L12 are focused from the short distance projection 48.5 "to the long distance projection 135", the primary image from the intermediate image side. Has a floating function FF that moves to the surface side.

<Second Embodiment>
FIG. 20 is an explanatory diagram illustrating a schematic configuration example of the projection optical system according to the second embodiment. In the illustrated example, the optical path at the reference projection distance is shown.
FIG. 21 is an explanatory diagram showing a configuration example of a main part of the projection optical system according to the second embodiment. In the illustrated example, a lens cross section of the first optical system L1 at the time of short-distance projection is shown.
As illustrated, the projection optical system 3 according to the second embodiment is different from the first embodiment described above in terms of the optical components that are moved to realize the screen shift function SF. In other words, the screen shift function SF is realized by moving some of the optical components constituting the eleventh optical system L11, not the entire eleventh optical system L11.
Further, the projection optical system 3 in the second embodiment is also different from that in the first embodiment described above with respect to the optical component that is moved to realize the zooming function MF.
Since the other configuration is the same as that of the first embodiment described above, the description thereof is omitted here.

  Here, the projection optical system 3 in the second embodiment will be briefly described below by giving specific numerical examples.

  FIG. 22 is a lateral aberration diagram of the projection optical system in the second embodiment. In the figure, one scale is one dot size when one dot size is enlarged and projected on the screen. The solid line is 546.1 nm, the dotted line is 620 nm, and the dashed line is 460 nm. The lateral aberration diagram shown here is a lateral aberration diagram when moved in the y direction. Of course, the moving direction is not limited to the y direction, and may be any direction as long as it is perpendicular to the optical axis.

  FIG. 23 is an explanatory diagram of a specific example of lens data of the projection optical system according to the second embodiment. In the figure, * indicates a surface having an aspherical surface, and follows the above equation (7). In addition, the circles are dummy surfaces, and the first and second flat reflecting surfaces are arranged respectively. r is the radius of curvature, d is the distance and the core thickness of the lens, nd is the refractive index at the d line (587.56 nm), and νd is the Abbe number at the d line. Further, the lens group grouped by {is a lens group related to the floating function FF, the zoom function MF, and the screen shift function SF. Further, di is a lens interval that varies when the floating function FF and the magnification function MF are realized.

  FIG. 24 shows a specific example of the numerical aperture NA on the primary image plane side, the maximum half angle of view ω at the reference projection distance, and the maximum primary image plane height y in the second embodiment. It is explanatory drawing.

FIG. 25A is an explanatory diagram illustrating a specific example of a lens group having a screen shift function SF and a movement amount in the projection optical system according to the second embodiment.
FIGS. 25B and 25C are explanatory diagrams illustrating specific examples of lens intervals related to the floating function FF and the zoom function MF in the projection optical system according to the second embodiment. The numerical values in the figure correspond to di in FIG. Here, fl is the focal length, and β is the magnification.

  FIG. 26 is an explanatory diagram of a specific example of an aspheric coefficient corresponding to the projection optical system according to the second embodiment. The aspheric coefficient in the example corresponds to the above equation (7).

  FIG. 27 is an explanatory diagram illustrating a specific example of an image modulation element according to the second embodiment. The one-dot size in the lateral aberration of FIG. 22 described above indicates the size described here.

FIG. 28 is an explanatory diagram showing a TV distortion state when the image modulation element shown in FIG. 27 is enlarged and projected onto the secondary image plane using the projection optical system according to the second embodiment.
FIG. 29 shows the amount of change in diagonal size, image distortion, and the like when the image modulation element shown in FIG. 27 is enlarged and projected onto the secondary image plane using the projection optical system in the second embodiment. It is explanatory drawing which shows a specific example. Note that the amount of change in the example shown in FIG. 18 is based on the calculation formula shown in FIG.

  FIG. 30 is an explanatory diagram illustrating an example of specific numerical values of the conditional expressions (1) to (6) in the projection optical system according to the second embodiment.

  According to the projection optical system 3 specified by the specific numerical examples as described above, as the screen shift function SF, one lens of the eleventh optical system L11 that is a part of the first optical system L1 is connected to the optical axis. And ± 0.1 mm vertical movement enables a screen shift of about ± 0.7%. Also, as the magnification function MF, the same lens as in the case of the screen shift function SF is moved on the optical axis, thereby changing the enlargement magnification of about ± 0.4%. Further, the floating function of moving the 12th group L12b constituting the twelfth optical system L12 from the intermediate image side to the primary image plane side when focusing from 55 ″ during short distance projection to 100 ″ during long distance projection. Has FF.

<Third Embodiment>
FIG. 31 is an explanatory diagram illustrating a schematic configuration example of the projection optical system according to the third embodiment. In the illustrated example, the optical path at the reference projection distance is shown.
FIG. 32 is an explanatory diagram showing a configuration example of a main part of the projection optical system according to the third embodiment. In the illustrated example, a lens cross section of the first optical system L1 at the time of short-distance projection is shown.
As shown in the figure, the projection optical system 3 in the third embodiment moves the entire eleventh optical system L11 in the same manner as in the first embodiment described above, thereby moving the screen shift function SF. To realize.
However, unlike the case of the first embodiment described above, the zooming function MF is realized by moving the two groups constituting the eleventh optical system L11 on the optical axis. Yes.
Since the other configuration is the same as that of the first embodiment described above, the description thereof is omitted here.

  Here, the projection optical system 3 in the third embodiment will be briefly described below by giving specific numerical examples.

  FIG. 33 is a lateral aberration diagram of the projection optical system in the third embodiment. In the figure, one scale is one dot size when one dot size is enlarged and projected on the screen. The solid line is 546.1 nm, the dotted line is 620 nm, and the dashed line is 460 nm. The lateral aberration diagram shown here is a lateral aberration diagram when moved in the y direction. Of course, the moving direction is not limited to the y direction, and may be any direction as long as it is perpendicular to the optical axis.

  FIG. 34 is an explanatory diagram of a specific example of lens data of the projection optical system according to the third embodiment. In the figure, * indicates a surface having an aspherical surface, and follows the above equation (7). r is the radius of curvature, d is the distance and the core thickness of the lens, nd is the refractive index at the d line (587.56 nm), and νd is the Abbe number at the d line. Further, the lens group grouped by {is a lens group related to the floating function FF, the zoom function MF, and the screen shift function SF. Further, di is a lens interval that varies when the floating function FF and the magnification function MF are realized.

  FIG. 35 shows a specific example of the numerical aperture NA on the primary image plane side, the maximum half field angle ω at the reference projection distance, and the maximum primary image plane height y in the third embodiment. It is explanatory drawing.

FIG. 36A is an explanatory diagram illustrating a specific example of a lens group having the screen shift function SF and a movement amount in the projection optical system according to the third embodiment.
FIGS. 36B and 36C are explanatory views showing specific examples of lens intervals related to the floating function FF and the variable magnification function MF in the projection optical system according to the third embodiment. The numerical value in the figure corresponds to di in FIG. Here, fl is the focal length, and β is the magnification.

  FIG. 37 is an explanatory diagram of a specific example of an aspheric coefficient corresponding to the projection optical system according to the third embodiment. The aspheric coefficient in the example corresponds to the above equation (7).

  FIG. 38 is an explanatory diagram illustrating a specific example of an image modulation element according to the third embodiment. The one dot size in the lateral aberration of FIG. 33 described above indicates the size described here.

FIG. 39 is an explanatory diagram showing a TV distortion state when the image modulation element shown in FIG. 38 is enlarged and projected onto the secondary image plane using the projection optical system according to the third embodiment.
FIG. 40 shows the amount of change in diagonal size, image distortion, and the like when the image modulation element shown in FIG. 38 is enlarged and projected onto the secondary image plane using the projection optical system in the third embodiment. It is explanatory drawing which shows a specific example. Note that the amount of change in the example shown in FIG. 18 is based on the calculation formula shown in FIG.

  FIG. 41 is an explanatory diagram showing an example of specific numerical values of the conditional expressions (1) to (6) in the projection optical system according to the third embodiment.

  According to the projection optical system 3 specified by the specific numerical examples as described above, as the screen shift function SF, the entire eleventh optical system L11 which is a part of the first optical system L1 is replaced with the optical axis. By moving 0.15 mm vertically, it is possible to shift the screen by about ± 2%. Further, as the magnification changing function MF, the two groups constituting the eleventh optical system L11 are moved on the optical axis, thereby changing the enlargement magnification of about ± 0.7%. Further, the 12th group L12a and the 12b group L12b constituting the twelfth optical system L12 are moved from the intermediate image side to the primary image plane side when focusing from 50 ″ during short distance projection to 100 ″ during long distance projection. Has a floating function FF to move to.

<Fourth embodiment>
FIG. 42 is an explanatory diagram illustrating a schematic configuration example of the projection optical system according to the fourth embodiment. In the illustrated example, the optical path at the reference projection distance is shown.
FIG. 43 is an explanatory diagram showing a configuration example of a main part of the projection optical system according to the fourth embodiment. In the illustrated example, a lens cross section of the first optical system L1 at the time of short-distance projection is shown.
As shown in the figure, the projection optical system 3 in the fourth embodiment has a screen shift function SF1 and a screen shift function SF2. The screen shift function SF1 is realized by the entire movement of the first optical system L1. On the other hand, the screen shift function SF2 is realized by moving the entire twelfth optical system L12, which is a part of the first optical system L1.
The scaling function MF is realized by moving two groups constituting the eleventh optical system L11 on the optical axis, as in the case of the third embodiment described above.
Since the other configuration is the same as that of the first embodiment described above, the description thereof is omitted here.

  Here, the projection optical system 3 according to the fourth embodiment will be briefly described below with specific numerical examples.

  FIG. 44 is a lateral aberration diagram of the projection optical system in the fourth embodiment. In the figure, one scale is one dot size when one dot size is enlarged and projected on the screen. The solid line is 546.1 nm, the dotted line is 620 nm, and the dashed line is 460 nm. The lateral aberration diagram shown here is a lateral aberration diagram when moved in the y direction. Of course, the moving direction is not limited to the y direction, and may be any direction as long as it is perpendicular to the optical axis.

  FIG. 45 is an explanatory diagram of a specific example of lens data of the projection optical system according to the fourth embodiment. In the figure, * indicates a surface having an aspherical surface, and follows the above equation (7). r is the radius of curvature, d is the distance and the core thickness of the lens, nd is the refractive index at the d line (587.56 nm), and νd is the Abbe number at the d line. Further, the lens group grouped by {is a lens group related to the floating function FF, the zoom function MF, and the screen shift function SF. Further, di is a lens interval that varies when the floating function FF and the magnification function MF are realized.

  FIG. 46 shows a specific example of the numerical aperture NA on the primary image plane side, the maximum half field angle ω at the reference projection distance, and the maximum primary image plane height y in the fourth embodiment. It is explanatory drawing.

FIG. 47A is an explanatory diagram illustrating a specific example of a lens group having the screen shift function SF1 and a lens group having the screen shift function SF2 and a movement amount in the projection optical system according to the fourth embodiment.
FIGS. 47B and 47C are explanatory diagrams showing specific examples of the lens interval related to the floating function FF and the variable magnification function MF in the projection optical system according to the fourth embodiment. The numerical values in the figure correspond to di in FIG. Here, fl is the focal length, and β is the magnification.

  FIG. 48 is an explanatory diagram of specific examples of aspheric coefficients corresponding to the projection optical system according to the fourth embodiment. The aspheric coefficient in the example corresponds to the above equation (7).

  FIG. 49 is an explanatory diagram illustrating a specific example of an image modulation element according to the fourth embodiment. The one-dot size in the lateral aberration of FIG. 44 described above indicates the size described here.

FIG. 50 is an explanatory diagram showing a TV distortion state when the image modulation element shown in FIG. 49 is enlarged and projected onto the secondary image plane using the projection optical system according to the fourth embodiment.
FIG. 51 shows the amount of change in diagonal size, image distortion, etc., when the image modulation element shown in FIG. 49 is enlarged and projected onto the secondary image plane using the projection optical system in the fourth embodiment. It is explanatory drawing which shows a specific example. Note that the amount of change in the example shown in FIG. 18 is based on the calculation formula shown in FIG.

  FIG. 52 is an explanatory diagram showing an example of specific numerical values of the conditional expressions (1) to (6) in the projection optical system according to the fourth embodiment.

  According to the projection optical system 3 specified by the specific numerical examples as described above, as the screen shift function SF1, the entire first optical system L1 is moved vertically by ± 0.1 mm from the optical axis, A screen shift of about ± 3% is possible. Further, as the screen shift function SF2, by moving the entire twelfth optical system L12, which is a part of the first optical system L1, perpendicular to the optical axis by ± 0.1 mm, a screen of about ± 0.6% is obtained. Allows shift. Further, as the magnification function MF, the two groups constituting the eleventh optical system L11 are moved on the optical axis, thereby changing the magnification of about ± 0.3%. Further, the 12th lens group L12a and the 12th lens group L12b constituting the twelfth optical system L12 are focused from the intermediate image side to the primary image surface side when focusing from 20 ″ during short distance projection to 100 ″ during long distance projection. Has a floating function FF to move to.

  In the configuration according to the fourth embodiment, the image modulation element is configured by a square of 5.6 mm × 5.6 mm, and a vertically long screen or a horizontally long screen can be projected depending on the application. Therefore, for example, it is optimal for use in the case of a usage pattern in which the image is projected onto the table shown in FIG.

<Fifth embodiment>
FIG. 53 is an explanatory diagram showing a schematic configuration example of the projection optical system according to the fifth embodiment. In the illustrated example, the optical path at the reference projection distance is shown.
FIG. 54 is an explanatory diagram showing a configuration example of a main part of the projection optical system according to the fifth embodiment. In the illustrated example, a lens cross section of the first optical system L1 at the time of short-distance projection is shown. In the figure, the most enlarged side is “wide”, and the most reduced side is “tele”.
As illustrated, the projection optical system 3 in the fifth embodiment moves the entire eleventh optical system L11 in the same manner as in the first embodiment described above, thereby moving the screen shift function SF. To realize.
The eleventh optical system L11 includes, from the primary image plane side, an eleventh group L11a having a positive refractive power, an eleventh group L11b having a positive refractive power, an eleventh group L11c having a negative refractive power, and The lens unit includes four lens units of the 11d group L11d having positive refractive power. Among these, the zoom function MF is realized by the eleventh group L11b and the eleventh group L11d moving on the optical axis.
Since the other configuration is the same as that of the first embodiment described above, the description thereof is omitted here.

  Here, the projection optical system 3 in the fifth embodiment will be briefly described below by giving specific numerical examples.

  FIG. 55 is a lateral aberration diagram of the projection optical system in the fifth embodiment. In the figure, one scale is one dot size when one dot size is enlarged and projected on the screen. The solid line is 546.1 nm, the dotted line is 620 nm, and the dashed line is 460 nm. The lateral aberration diagram shown here is a lateral aberration diagram when moved in the y direction. Of course, the moving direction is not limited to the y direction, and may be any direction as long as it is perpendicular to the optical axis.

  FIG. 56 is an explanatory diagram of a specific example of lens data of the projection optical system according to the fifth embodiment. In the figure, * indicates a surface having an aspherical surface, and follows the above equation (7). r is the radius of curvature, d is the distance and the core thickness of the lens, nd is the refractive index at the d line (587.56 nm), and νd is the Abbe number at the d line. Further, the lens group grouped by {is a lens group related to the floating function FF, the zoom function MF, and the screen shift function SF. Further, di is a lens interval that varies when the floating function FF and the magnification function MF are realized.

  FIG. 57 shows a specific example of the numerical aperture NA on the primary image plane side, the maximum half angle of view ω at the reference projection distance, and the maximum primary image plane height y in the fifth embodiment. It is explanatory drawing.

FIG. 58 is an explanatory diagram illustrating a specific example of the lens group having the screen shift function SF1 and the amount of movement in the projection optical system according to the fifth embodiment.
FIG. 59 is an explanatory diagram showing a specific example of the lens interval related to the floating function FF and the magnification function MF in the projection optical system according to the fifth embodiment. The numerical values in the figure correspond to di in FIG. Here, fl is the focal length, and β is the magnification.

  FIG. 60 is an explanatory diagram of a specific example of an aspheric coefficient corresponding to the projection optical system in the fifth embodiment. The aspheric coefficient in the example corresponds to the above equation (7).

  FIG. 61 is an explanatory diagram illustrating a specific example of an image modulation element according to the fifth embodiment. The one-dot size in the lateral aberration of FIG. 55 described above indicates the size described here.

FIG. 62 is an explanatory diagram showing a TV distortion state when the image modulation element shown in FIG. 61 is enlarged and projected onto the secondary image plane using the projection optical system according to the fifth embodiment.
FIG. 63 shows the amount of change in diagonal size, image distortion, and the like when the image modulation element shown in FIG. 61 is enlarged and projected onto the secondary image plane using the projection optical system in the fifth embodiment. It is explanatory drawing which shows a specific example. Note that the amount of change in the example shown in FIG. 18 is based on the calculation formula shown in FIG.

  FIG. 64 is an explanatory diagram illustrating an example of specific numerical values of the conditional expressions (1) to (6) in the projection optical system according to the fifth embodiment.

  According to the projection optical system 3 specified by the specific numerical example as described above, as the screen shift function SF, the entire eleventh optical system L11 is moved vertically by ± 0.1 mm from the optical axis, A screen shift of about ± 1.7% is possible. Further, as the magnification function MF, the magnification ratio of about ± 10% is changed by moving the 11b group L11b and the 11d group L11d in the 11th optical system L11 on the optical axis. Further, the 12a group L12a and the 12b group L12b constituting the twelfth optical system L12 are set to 1 from the intermediate image side at the time of focusing from 60 ″ at the short distance projection to 100 ″ at the long distance projection at the time of Wide, for example. It has a floating function FF that moves to the next image plane side. This function is the same on the reduction side (Tele), in which case the change is from 54.55 "to 90.91".

<Sixth Embodiment>
FIG. 65 is an explanatory diagram illustrating a schematic configuration example of the projection optical system according to the sixth embodiment. In the illustrated example, the optical path at the reference projection distance is shown.
FIG. 66 is an explanatory diagram showing a configuration example of a main part of the projection optical system according to the sixth embodiment. In the illustrated example, a lens cross section of the first optical system L1 at the time of short-distance projection is shown. In the figure, the most enlarged side is “wide”, and the most reduced side is “tele”.
As illustrated, the projection optical system 3 in the fifth embodiment moves the entire eleventh optical system L11 in the same manner as in the first embodiment described above, thereby moving the screen shift function SF. To realize.
The eleventh optical system L11 includes, from the primary image plane side, an eleventh group L11a having a positive refractive power, an eleventh group L11b having a positive refractive power, an eleventh group L11c having a negative refractive power, and The lens unit includes four lens units of the 11d group L11d having positive refractive power. Among these, the zoom function MF is realized by the eleventh group L11b, the eleventh group L11c, and the eleventh group L11d moving on the optical axis.
Since the other configuration is the same as that of the first embodiment described above, the description thereof is omitted here.

  Here, the projection optical system 3 according to the sixth embodiment will be briefly described below by giving specific numerical examples.

  FIG. 67 is a lateral aberration diagram of the projection optical system in the sixth embodiment. In the figure, one scale is one dot size when one dot size is enlarged and projected on the screen. The solid line is 546.1 nm, the dotted line is 620 nm, and the dashed line is 460 nm. The lateral aberration diagram shown here is a lateral aberration diagram when moved in the y direction. Of course, the moving direction is not limited to the y direction, and may be any direction as long as it is perpendicular to the optical axis.

  FIG. 68 is an explanatory diagram of a specific example of lens data of the projection optical system according to the sixth embodiment. In the figure, * indicates a surface having an aspherical surface, and follows the above equation (7). r is the radius of curvature, d is the distance and the core thickness of the lens, nd is the refractive index at the d line (587.56 nm), and νd is the Abbe number at the d line. Further, the lens group grouped by {is a lens group related to the floating function FF, the zoom function MF, and the screen shift function SF. Further, di is a lens interval that varies when the floating function FF and the magnification function MF are realized.

  FIG. 69 shows a specific example of the numerical aperture NA on the primary image plane side, the maximum half angle of view ω at the reference projection distance, and the maximum primary image plane height y in the sixth embodiment. It is explanatory drawing.

FIG. 70 is an explanatory diagram illustrating a specific example of a lens group having the screen shift function SF1 and a movement amount in the projection optical system according to the sixth embodiment.
FIG. 71 is an explanatory diagram showing a specific example of a lens interval related to the floating function FF and the zoom function MF in the projection optical system according to the sixth embodiment. The numerical values in the figure correspond to di in FIG. Here, fl is the focal length, and β is the magnification.

  FIG. 72 is an explanatory diagram of a specific example of an aspheric coefficient corresponding to the projection optical system in the sixth embodiment. The aspheric coefficient in the example corresponds to the above equation (7).

  FIG. 73 is an explanatory diagram showing a specific example of an image modulation element according to the sixth embodiment. The one dot size in the lateral aberration of FIG. 67 described above indicates the size described here.

FIG. 74 is an explanatory diagram showing a TV distortion state when the image modulation element shown in FIG. 73 is enlarged and projected onto the secondary image plane by using the projection optical system in the sixth embodiment.
FIG. 75 shows the amount of change in diagonal size, image distortion, etc., when the image modulation element shown in FIG. 73 is enlarged and projected onto the secondary image plane using the projection optical system in the sixth embodiment. It is explanatory drawing which shows a specific example. Note that the amount of change in the example shown in FIG. 18 is based on the calculation formula shown in FIG.

  FIG. 76 is an explanatory diagram illustrating an example of specific numerical values of conditional expressions (1) to (6) in the projection optical system according to the sixth embodiment.

  According to the projection optical system 3 specified by the specific numerical example as described above, as the screen shift function SF, the entire eleventh optical system L11 is moved vertically by ± 0.1 mm from the optical axis, A screen shift of about ± 1.7% is possible. Further, as the magnification function MF, the magnification ratio of about ± 20% is changed by moving the 11b group L11b, the 11c group L11c, and the 11d group L11d in the 11th optical system L11 on the optical axis. Further, the 12a group L12a and the 12b group L12b constituting the twelfth optical system L12 are set to 1 from the intermediate image side at the time of focusing from 60 ″ at the short distance projection to 100 ″ at the long distance projection at the time of Wide, for example. It has a floating function FF that moves to the next image plane side. This function is the same on the reduction side (Tele), and in this case, the change is from 49.59 ″ to 82.65 ″.

  By including any one of the configurations of the first to sixth embodiments described above, the screen shift function SF, while having a half angle of view of 70 degrees, a super wide angle near numerical aperture of 0.3, and a large aperture, The projection optical system 3 can be provided with the zoom function MF and the floating function FF. In addition, each of these functions can be realized in a small size and at a low cost.

In addition, when using the projection optical system 3 corresponding to a super wide angle and a large aperture, the liquid crystal projector device configured to include the projection optical system 3 becomes very sensitive to the installation environment. In other words, there is a possibility that the projected screen may shake in response to vibrations that were not noticed in a conventional liquid crystal projector device that does not support ultra-wide angle or the like.
For this reason, it is conceivable to adopt the configuration described below for the liquid crystal projector device configured to include the projection optical system 3. That is, the screen amplitude is detected by an infrared sensor, or the apparatus itself is configured to detect vibration. Then, the amplitude or vibration information is synchronized with a mechanism that moves some optical components of the first optical system L1 substantially perpendicular to the optical axis. This makes it possible to correct screen vibration. In this case, the infrared sensor, the detection structure, the means for synchronizing, and the like may be realized by using a known technique, and thus the specific description thereof is omitted here.

[Other configuration examples of projection optical system]
Next, another configuration example of the projection optical system 3 will be described.
In the case of the projection optical system 3 that uses a large curved reflecting surface, the dimensions in the height direction tend to be large when considering the overall configuration of the liquid crystal projector apparatus including the substrate for driving the image modulation element and the cooling mechanism. is there. From this, it can be considered that the projection optical system 3 used in the liquid crystal projector apparatus is configured as described below.
Hereinafter, the configuration of the projection optical system 3 will be described in order by taking the seventh to tenth embodiments as examples.

<Seventh embodiment>
FIG. 77 is an explanatory diagram showing a schematic configuration example of the projection optical system according to the seventh embodiment.
As shown in the drawing, the projection optical system 3 in the seventh embodiment has a first optical system L1 and a second optical system L2 as in the case of the first embodiment described above. . The first optical system L1 includes an eleventh optical system L11 and a twelfth optical system L12 arranged from the primary image plane side.
However, in the projection optical system 3 in the seventh embodiment, unlike the case of the first embodiment described above, the first planar reflecting surface is provided between the eleventh optical system L11 and the twelfth optical system L12. M1 is arranged. In addition, a second planar reflecting surface M2 is disposed between the first optical system L1 and the second optical system L2. Furthermore, a transparent parallel plate T having a refractive index n is disposed between the second optical system L2 and the secondary image plane.
Since the other configuration is the same as that of the first embodiment described above, the description thereof is omitted here. Since specific configurations (formation materials and the like) of the first planar reflection surface M1, the second planar reflection surface M2, and the parallel flat plate T may be realized using a known technique, the description thereof is omitted here.

  For the first planar reflecting surface M1, the y-axis rotation angle β1 of the first planar reflecting surface M1 and the x-axis rotation angle α1 of the first planar reflecting surface M1 are the following conditional expressions (8) and conditional expressions: It arrange | positions so that (9) may be satisfy | filled. Here, the y-axis rotation angle means a rotation angle around the y-axis. The x-axis rotation angle refers to a rotation angle around the x-axis. The y-axis and the x-axis are reference axes on the plane when the installation surface of the liquid crystal projector device is the xy plane.

  30 ° <| β1 | <65 ° (8)

  3 ° <α1 <15 ° (9)

  The conditional expressions (8) and (9) are for reducing the size of the liquid crystal projector device in the height direction (z-axis direction orthogonal to the xy plane). That is, if the lower limit of conditional expression (8) is not satisfied, the eleventh optical system L11 and the twelfth optical system L12 may interfere with each other. If the upper limit is exceeded, the first planar reflecting surface M1 and the eleventh optical system L11 or the twelfth optical system L12 may interfere with each other. On the other hand, when the lower limit of the conditional expression (9) is not satisfied, the light source protrudes greatly with respect to the height direction of the concave reflecting surface, and the height direction dimension of the apparatus increases. In addition, when the upper limit is exceeded, the substrate for driving the image modulation element or the components for cooling the image modulation element protrudes in the height direction of the concave reflecting surface. Increase in size.

  That is, as defined by the conditional expressions (8) and (9), the first planar reflecting surface M1 has a rotation angle with respect to both the y-axis and the x-axis. Accordingly, the size in the z-axis direction perpendicular to the xy plane, that is, the size in the height direction of the liquid crystal projector device can be suppressed to be smaller than when only one of the y-axis and the x-axis has a rotation angle. It is.

  The first planar reflection surface M1 may be configured to satisfy the total reflection condition. This configuration is effective when it is desired to achieve a brighter optical system.

  For the second plane reflecting surface M2, the y-axis rotation angle β2 of the second plane reflecting surface M2 and the x-axis rotation angle α2 of the second plane reflecting surface M2 are the following conditional expressions (10) and conditional expressions: It arrange | positions so that (11) may be satisfy | filled.

  20 ° <| β2 | <45 ° (10)

  3 ° <α2 <15 ° (11)

  The conditional expressions (10) and (11) are for reducing the size of the liquid crystal projector device in the height direction (z-axis direction orthogonal to the xy plane). That is, if the lower limit of conditional expression (10) is not satisfied, the eleventh optical system L11 and the twelfth optical system L12 may interfere with each other. When the upper limit is exceeded, the second optical system L2 and the image modulation element are separated from each other, resulting in an increase in the size of the entire apparatus. On the other hand, when the upper limit of conditional expression (11) is exceeded, the light source protrudes greatly with respect to the height direction of the concave reflecting surface, and the height direction dimension of the apparatus increases. If the lower limit is not reached, the substrate for driving the image modulation element or the components for cooling the image modulation element will protrude in the height direction of the concave reflecting surface. Increases in size.

  In addition, it is desirable that the first planar reflection surface M1 and the second planar reflection surface M2 are arranged so as to satisfy the following conditional expressions (12) and (13).

  −20 ° <α1 + α2 <20 ° (12)

  70 ° <β1 + β2 <110 ° (13)

The conditional expressions (12) and (13) are effective particularly when a mercury lamp is used as the light source. That is, the conditional expressions (12) and (13) are conditions for placing the arc portion of the light source substantially horizontally, and when the upper and lower limits are exceeded, it is conceivable that the life of the light source deteriorates rapidly.
The condition defined in the conditional expression (12) is effective when a plane perpendicular to the ground, such as a wall or an electronic blackboard, becomes the projection surface (see, for example, FIG. 1). Further, the condition defined in the conditional expression (13) is effective when projection on the table is performed (for example, see FIG. 5).
When both the conditional expression (12) and the conditional expression (13) are satisfied, the configuration is compatible with all projection forms. That is, in that case, the light source is disposed on the back surface side of the concave reflecting surface.

  About the parallel plate T, it arrange | positions so that the x-axis rotation angle (alpha) t of the said parallel plate T may satisfy the following conditional expressions (14).

  60 ° <αt <87 ° (14)

Since there is also a dustproof effect, it is effective to insert a parallel plate T between the second optical system L2 and the secondary image plane. However, for example, when the parallel plate T is arranged substantially parallel to the optical axis, a part of the light beam incident on the secondary image plane enters the parallel plate T at a very shallow angle. For this reason, the reflectance of the light flux is increased on the antireflection film for increasing the transmittance, and as a result, it may cause deterioration of brightness, generation of ghost, and the like.
Therefore, with respect to the parallel plate T, it is effective to give an inclination within the range defined by the conditional expression (14). That is, if the parallel plate T is disposed at an angle exceeding the lower limit of the conditional expression (14), the reflectance can be reduced. On the other hand, when the upper limit is exceeded, the height of the entire apparatus including the parallel plate T and the secondary optical system L2 becomes large.

  In addition, a light shielding plate capable of completely shielding the image information from the image modulation element is disposed at a position immediately after emission of the parallel plate T, that is, a position on the secondary image plane side from the parallel plate T, and the light shielding plate is opened and closed. A flexible structure is also conceivable. By adopting such a structure, it is possible to switch ON / OFF of image information depending on the usage state without turning off the power.

Here, specific numerical examples of the projection optical system 3 in the seventh embodiment will be given.
FIG. 78 is an explanatory diagram showing an example of specific numerical values of conditional expressions (8) to (14) in the projection optical system according to the seventh embodiment.

  According to the projection optical system 3 specified by the specific numerical examples as described above, the height direction dimension when the liquid crystal projector apparatus is configured is set to, for example, about 130 mm by providing the angles α1 and α2. (See, for example, FIG. 77 (b)).

<Eighth Embodiment>
FIG. 79 is an explanatory diagram illustrating a schematic configuration example of the projection optical system according to the eighth embodiment.
As shown in the figure, the projection optical system 3 in the eighth embodiment is similar to the above-described seventh embodiment in that the first flat reflection surface M1, the second flat reflection surface M2, and the parallel flat plate T. It is configured with.

Here, specific numerical examples of the projection optical system 3 in the eighth embodiment will be given.
FIG. 80 is an explanatory diagram illustrating an example of specific numerical values of conditional expressions (8) to (14) in the projection optical system according to the eighth embodiment.

According to the projection optical system 3 specified by the specific numerical examples as described above, by setting the inclination of the parallel plate T to 85 °, the dimension in the height direction when the liquid crystal projector apparatus is configured, for example, It can be suppressed to about 120 mm (for example, see FIG. 79B).
FIG. 81 is an explanatory diagram showing a specific example of an optical path diagram including the secondary image plane at that time. The illustrated example is an optical path diagram at a reference projection distance and is projected when 80 ″ is projected.

<Ninth embodiment>
FIG. 82 is an explanatory diagram illustrating a schematic configuration example of the projection optical system according to the ninth embodiment.
As shown in the figure, the projection optical system 3 in the ninth embodiment is arranged on the optical path from the second optical system L2 to the secondary image plane in addition to the configuration in the eighth embodiment. A third flat reflecting surface M3 having one reflecting surface is detachably disposed.
Note that the specific configuration (formation material and the like) of the third planar reflecting surface M3 may be realized by using a known technique, and thus the description thereof is omitted here. Further, the mechanism that allows the third flat reflecting surface M3 to be attached and detached is not particularly limited, and may be realized using a known technique.

  About the 3rd plane reflective surface M3, it arrange | positions so that the x-axis rotation angle (alpha) 3 of the said 3rd plane reflective surface M3 may satisfy the following conditional expressions (15).

  −15 ° <α3 <0 ° (15)

  The conditional expression (15) is for reducing the projection space by the liquid crystal projector device. That is, by disposing the third planar reflecting surface M3 so as to fall within the range defined by the conditional expression (15), it is possible to reduce the projection space without increasing the third planar reflecting surface M3. Become. Specifically, when the lower limit of conditional expression (15) is not satisfied, the light beam traveling from the third planar reflecting surface M3 to the secondary image surface interferes with the projection optical system 3. On the other hand, when the upper limit is exceeded, the third planar reflecting surface M3 is increased in size.

  Moreover, about 3rd plane reflective surface M3, it becomes possible to change projection space according to a use by giving a detachable mechanism. Furthermore, since the user does not directly touch the vapor deposition film by reflecting the light beam on the back surface of the third flat reflecting surface M3, the handling becomes easy.

Here, specific numerical examples of the projection optical system 3 in the ninth embodiment will be given.
FIG. 83 is an explanatory diagram illustrating an example of specific numerical values of conditional expressions (8) to (15) in the projection optical system according to the ninth embodiment.
Thus, according to the projection optical system 3 in the ninth embodiment, by satisfying all of the conditional expressions (8) to (15), it is possible to provide a liquid crystal projector device that is small and has a narrow projection space. .

FIG. 84 is an explanatory diagram illustrating a specific example of an optical path diagram including a secondary image plane when a liquid crystal projector device is configured using the projection optical system according to the ninth embodiment. The illustrated example is an optical path diagram at the reference projection distance when 80 ″ is projected.
As shown in the figure, the projection space when the liquid crystal projector device is configured by installing the third plane reflecting surface M3 is set to 800 mm to 590 mm in the case of the above-described eighth embodiment (see FIG. 81). It becomes possible to make it significantly smaller.

  In the case where the third plane reflecting surface M3 is installed, the third plane reflecting surface M3 is formed of a parallel plate, and transmission between the optical path from the second optical system L2 to the secondary image plane is performed twice. It may be configured to repeat one reflection.

<Tenth Embodiment>
FIG. 85 is an explanatory diagram illustrating a schematic configuration example of the projection optical system according to the tenth embodiment.
As illustrated, the projection optical system 3 in the tenth embodiment is configured in substantially the same manner as in the seventh embodiment described above, but the total reflection prism TIR is used as the first planar reflection surface M1. The point that is using is different. Other configurations are the same as those in the case of the seventh embodiment described above, and thus the description thereof is omitted here. Further, the total reflection prism TIR may be realized by using a known technique, and thus the description thereof is omitted here.

Here, specific numerical examples of the projection optical system 3 in the tenth embodiment will be given.
FIG. 86 is an explanatory diagram showing an example of specific numerical values of conditional expressions (8) to (14) in the projection optical system according to the tenth embodiment.

  According to the projection optical system 3 specified by the specific numerical examples as described above, the height direction dimension when the liquid crystal projector apparatus is configured is set to, for example, about 130 mm by providing the angles α1 and α2. (For example, refer to FIG. 85B.)

In each of the above-described embodiments, preferred specific examples of the present invention have been described. However, the present invention is not limited to the contents.
In particular, the specific shapes and numerical values of the respective parts exemplified in the first to tenth embodiments are merely examples of the implementation performed in carrying out the present invention, and these are the technical aspects of the present invention. The range should not be interpreted in a limited way.
Further, for example, in each of the above-described embodiments, the liquid crystal projector apparatus has been described as an example of the projection type image display apparatus. However, other projection type image display apparatuses, that is, the image modulation elements other than the liquid crystal panel are used. Even so, the present invention can be applied in exactly the same manner.
Furthermore, for example, in each of the above-described embodiments, the projection optical system suitable as the optical system of the projection-type image display apparatus has been described. Of course, it can also be used as a system.
Thus, the present invention is not limited to the contents described in the present embodiment, and can be appropriately changed without departing from the gist thereof.

It is explanatory drawing (the 1) about the advantage of the liquid crystal projector apparatus corresponding to an ultra-wide angle. It is explanatory drawing (the 2) about the advantage of the liquid crystal projector apparatus corresponding to a super-wide angle. It is explanatory drawing (the 3) about the advantage of the liquid crystal projector apparatus corresponding to an ultra-wide angle. It is explanatory drawing (the 4) about the advantage of the liquid crystal projector apparatus corresponding to an ultra-wide angle. It is explanatory drawing (the 5) about the advantage of the liquid crystal projector apparatus corresponding to a super-wide angle. It is explanatory drawing which shows the schematic structural example of a liquid crystal projector device. It is explanatory drawing which shows the schematic structural example of the light source and illumination optical system in a liquid crystal projector device. It is an optical path figure which shows the schematic structural example of the projection optical system in 1st Embodiment. It is explanatory drawing which shows the principal part structural example of the projection optical system in 1st Embodiment. It is a lateral aberration diagram by the projection optical system in the first embodiment. It is explanatory drawing of the specific example of the lens data of the projection optical system in 1st Embodiment. It is explanatory drawing which shows the specific example of numerical aperture NA by the side of the primary image plane of the projection optical system in 1st Embodiment, the largest half field angle (omega) at the time of a reference | standard projection distance, and the largest primary image surface height y. . In the projection optical system in 1st Embodiment, it is explanatory drawing which shows the lens group which has a screen shift function, the specific example of a movement amount, and the specific example of the lens space | interval regarding a floating function and a magnification function. It is explanatory drawing of the specific example of the aspherical coefficient corresponding to the projection optical system in 1st Embodiment. It is explanatory drawing which shows the specific example of the image modulation element in 1st Embodiment. It is explanatory drawing which showed the state of TV distortion when the image modulation element shown in FIG. 15 was enlarged and projected on the secondary image surface using the projection optical system in 1st Embodiment. A specific example of the amount of change in diagonal size, image distortion, and the like when the image modulation element shown in FIG. 15 is enlarged and projected onto the secondary image plane using the projection optical system according to the first embodiment is shown. It is explanatory drawing. It is explanatory drawing which shows the specific example of the calculation formula based on calculating | requiring the variation | change_quantity etc. of diagonal size on a secondary image surface, image distortion, etc. FIG. It is explanatory drawing which shows an example of the specific numerical value of conditional expression (1)-(6) in the projection optical system in 1st Embodiment. It is explanatory drawing which shows the schematic structural example of the projection optical system in 2nd Embodiment. It is explanatory drawing which shows the principal part structural example of the projection optical system in 2nd Embodiment. It is a lateral aberration diagram by the projection optical system in the second embodiment. It is explanatory drawing of the specific example of the lens data of the projection optical system in 2nd Embodiment. It is explanatory drawing which shows the specific example of numerical aperture NA by the side of the primary image plane of the projection optical system in 2nd Embodiment, the maximum half field angle (omega) at the time of a reference | standard projection distance, and the maximum primary image plane height y. . In the projection optical system in 2nd Embodiment, it is explanatory drawing which shows the lens group which has a screen shift function, the specific example of a moving amount, and the specific example of the lens space | interval regarding a floating function and a magnification function. It is explanatory drawing of the specific example of the aspherical coefficient corresponding to the projection optical system in 2nd Embodiment. It is explanatory drawing which shows the specific example of the image modulation element in 2nd Embodiment. It is explanatory drawing which showed the state of TV distortion when the image modulation element shown in FIG. 27 was enlarged and projected on the secondary image surface using the projection optical system in 2nd Embodiment. 27 shows a specific example of the amount of change in diagonal size, image distortion, etc. when the image modulation element shown in FIG. 27 is enlarged and projected onto the secondary image plane using the projection optical system in the second embodiment. It is explanatory drawing. It is explanatory drawing which shows an example of the specific numerical value of conditional expression (1)-(6) in the projection optical system in 2nd Embodiment. It is explanatory drawing which shows the schematic structural example of the projection optical system in 3rd Embodiment. It is explanatory drawing which shows the principal part structural example of the projection optical system in 3rd Embodiment. It is a lateral aberration diagram by the projection optical system in the third embodiment. It is explanatory drawing of the specific example of the lens data of the projection optical system in 3rd Embodiment. It is explanatory drawing which shows the specific example of numerical aperture NA by the side of the primary image plane of the projection optical system in 3rd Embodiment, the maximum half field angle (omega) at the time of a reference | standard projection distance, and the maximum primary image plane height y. . In the projection optical system in 3rd Embodiment, it is explanatory drawing which shows the lens group which has a screen shift function, the specific example of a moving amount, and the specific example of the lens space | interval regarding a floating function and a magnification function. It is explanatory drawing of the specific example of the aspherical coefficient corresponding to the projection optical system in 3rd Embodiment. It is explanatory drawing which shows the specific example of the image modulation element in 3rd Embodiment. It is explanatory drawing which showed the state of TV distortion when the image modulation element shown in FIG. 38 was enlarged and projected on the secondary image surface using the projection optical system in 3rd Embodiment. A specific example of the amount of change in diagonal size, image distortion, and the like when the image modulation element shown in FIG. 38 is enlarged and projected onto the secondary image plane using the projection optical system according to the third embodiment. It is explanatory drawing. It is explanatory drawing which shows an example of the specific numerical value of conditional expression (1)-(6) in the projection optical system in 3rd Embodiment. It is explanatory drawing which shows the schematic structural example of the projection optical system in 4th Embodiment. It is explanatory drawing which shows the principal part structural example of the projection optical system in 4th Embodiment. It is a transverse aberration figure by the projection optical system in a 4th embodiment. It is explanatory drawing of the specific example of the lens data of the projection optical system in 4th Embodiment. It is explanatory drawing which shows the specific example of numerical aperture NA by the side of the primary image plane of the projection optical system in 4th Embodiment, the maximum half field angle (omega) at the time of a reference | standard projection distance, and the maximum primary image plane height y. . In the projection optical system in 4th Embodiment, it is explanatory drawing which shows the lens group which has a screen shift function, the specific example of a moving amount, and the specific example of the lens space | interval regarding a floating function and a magnification function. It is explanatory drawing of the specific example of the aspherical coefficient corresponding to the projection optical system in 4th Embodiment. It is explanatory drawing which shows the specific example of the image modulation element in 4th Embodiment. It is explanatory drawing which showed the state of TV distortion when the image modulation element shown in FIG. 49 was enlarged and projected on the secondary image surface using the projection optical system in 4th Embodiment. 49 shows a specific example of the amount of change in diagonal size, image distortion, etc. when the image modulation element shown in FIG. 49 is enlarged and projected onto the secondary image plane using the projection optical system in the fourth embodiment. It is explanatory drawing. It is explanatory drawing which shows an example of the specific numerical value of conditional expression (1)-(6) in the projection optical system in 4th Embodiment. It is explanatory drawing which shows the schematic structural example of the projection optical system in 5th Embodiment. It is explanatory drawing which shows the principal part structural example of the projection optical system in 5th Embodiment. It is a transverse aberration figure by the projection optical system in a 5th embodiment. It is explanatory drawing of the specific example of the lens data of the projection optical system in 5th Embodiment. It is explanatory drawing which shows the specific example of numerical aperture NA by the side of the primary image plane of the projection optical system in 5th Embodiment, the largest half field angle (omega) at the time of a reference | standard projection distance, and the largest primary image surface height y. . In the projection optical system in 5th Embodiment, it is explanatory drawing which shows the specific example of the lens group which has a screen shift function, and a moving amount | distance. In the projection optical system in 5th Embodiment, it is explanatory drawing which shows the specific example of the lens space | interval regarding a floating function and a magnification function. It is explanatory drawing of the specific example of the aspherical coefficient corresponding to the projection optical system in 5th Embodiment. It is explanatory drawing which shows the specific example of the image modulation element in 5th Embodiment. FIG. 66 is an explanatory diagram showing a TV distortion state when the image modulation element shown in FIG. 61 is enlarged and projected onto the secondary image plane using the projection optical system according to the fifth embodiment. 61 shows a specific example of the amount of change in diagonal size, image distortion, etc. when the image modulation element shown in FIG. 61 is enlarged and projected onto the secondary image plane using the projection optical system in the fifth embodiment. It is explanatory drawing. It is explanatory drawing which shows an example of the concrete numerical value of conditional expression (1)-(6) in the projection optical system in 5th Embodiment. It is explanatory drawing which shows the schematic structural example of the projection optical system in 6th Embodiment. It is explanatory drawing which shows the principal part structural example of the projection optical system in 6th Embodiment. It is a transverse aberration figure by the projection optical system in a 6th embodiment. It is explanatory drawing of the specific example of the lens data of the projection optical system in 6th Embodiment. It is explanatory drawing which shows the specific example of numerical aperture NA by the side of the primary image plane of the projection optical system in 6th Embodiment, the maximum half field angle (omega) at the time of a reference | standard projection distance, and the maximum primary image plane height y. . In the projection optical system in 6th Embodiment, it is explanatory drawing which shows the specific example of the lens group which has a screen shift function, and a moving amount | distance. It is explanatory drawing which shows the specific example of the lens space | interval regarding a floating function and a magnification function in the projection optical system in 6th Embodiment. It is explanatory drawing of the specific example of the aspherical coefficient corresponding to the projection optical system in 6th Embodiment. It is explanatory drawing which shows the specific example of the image modulation element in 6th Embodiment. FIG. 74 is an explanatory diagram showing a TV distortion state when the image modulation element shown in FIG. 73 is enlarged and projected onto the secondary image plane using the projection optical system according to the sixth embodiment. 73 shows a specific example of the amount of change in diagonal size, image distortion, etc. when the image modulation element shown in FIG. 73 is enlarged and projected onto the secondary image plane using the projection optical system in the sixth embodiment. It is explanatory drawing. It is explanatory drawing which shows an example of the specific numerical value of conditional expression (1)-(6) in the projection optical system in 6th Embodiment. It is explanatory drawing which shows the schematic structural example of the projection optical system in 7th Embodiment. It is explanatory drawing which shows an example of the specific numerical value of conditional expression (8)-(14) in the projection optical system in 7th Embodiment. It is explanatory drawing which shows the schematic structural example of the projection optical system in 8th Embodiment. It is explanatory drawing which shows an example of the specific numerical value of conditional expression (8)-(14) in the projection optical system in 8th Embodiment. It is explanatory drawing which shows the specific example of the optical path figure including the secondary image surface at the time of comprising a liquid crystal projector apparatus using the projection optical system in 8th Embodiment. It is explanatory drawing which shows the schematic structural example of the projection optical system in 9th Embodiment. It is explanatory drawing which shows an example of the specific numerical value of conditional expression (8)-(15) in the projection optical system in 9th Embodiment. It is explanatory drawing which shows the specific example of the optical path figure including the secondary image surface at the time of comprising a liquid crystal projector apparatus using the projection optical system in 9th Embodiment. It is explanatory drawing which shows the schematic structural example of the projection optical system in 10th Embodiment. It is explanatory drawing which shows an example of the specific numerical value of conditional expression (8)-(14) in the projection optical system in 10th Embodiment. It is explanatory drawing of incident angle (theta) with respect to a screen. It is explanatory drawing of a specific example of the screen shift function used with the conventional liquid crystal projector apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Light source, 2 ... Illumination optical system, 3 ... Projection optical system, P ... Image modulation element (liquid crystal panel), L1 ... 1st optical system, L2 ... 2nd optical system, L11 ... 11th optical system, L12 ... 1st 12 optical systems, L11a ... 11a group, L11b ... 11b group, L11c ... 11c group, L11d ... 11d group, L12a ... 12a group, L12b ... 12b group, SF ... screen shift function, MF ... magnification Function, FF ... Floating function, M1 ... First plane reflecting surface, M2 ... Second plane reflecting surface, M3 ... Third plane reflecting surface, T ... Parallel plate

Claims (12)

A light source;
An illumination optical system for uniformly irradiating the light beam emitted from the light source onto the surface of the image modulation element serving as a primary image plane;
A projection optical system for enlarging and projecting image information of the primary image plane modulated by the image modulation element onto a screen serving as a secondary image plane;
The projection optical system is
A first optical system having a positive refractive power;
A second optical system having a concave reflecting surface;
The first optical system includes:
An eleventh optical system having a positive refractive power on the primary image plane side;
A twelfth optical system having a negative refractive power on the side of the secondary image plane from the eleventh optical system;
A first planar reflecting surface disposed between the eleventh optical system and the twelfth optical system;
The y-axis rotation angle β1 of the first plane reflection surface is 30 ° <| β1 | <65 °, and the x-axis rotation angle α1 of the first plane reflection surface is 3 ° <α1 <15 °. Display device. The projection type image display apparatus according to claim 1, wherein the first planar reflection surface satisfies a total reflection condition. A second planar reflecting surface disposed between the first optical system and the second optical system;
The y-axis rotation angle β2 of the second plane reflection surface is 20 ° <| β2 | <45 °, and the x-axis rotation angle α2 of the second plane reflection surface is −15 ° <α2 <−3 °. Item 3. The projection type image display device according to Item 1 or 2. The projection type image display apparatus according to claim 3, wherein an x-axis rotation angle α1 of the first plane reflection surface and an x-axis rotation angle α2 of the second plane reflection surface satisfy a relationship of −20 ° <α1 + α2 <20 °. The projection type image display apparatus according to claim 3, wherein the y-axis rotation angle β1 of the first plane reflection surface and the y-axis rotation angle β2 of the second plane reflection surface satisfy a relationship of 70 ° <β1 + β2 <110 °. The light source is disposed on the back side of the concave reflecting surface of the second optical system,
The x-axis rotation angle α1 of the first plane reflection surface and the x-axis rotation angle α2 of the second plane reflection surface satisfy a relationship of −20 ° <α1 + α2 <20 °,
The projection type image display apparatus according to claim 3, wherein the y-axis rotation angle β1 of the first plane reflection surface and the y-axis rotation angle β2 of the second plane reflection surface satisfy a relationship of 70 ° <β1 + β2 <110 °. A third planar reflecting surface having one reflecting surface is detachably disposed on the optical path from the second optical system to the secondary image surface, and
7. The projection type image display device according to claim 1, wherein an x-axis rotation angle α <b> 3 of the third plane reflecting surface is −15 ° <α <3><0 °. The projection-type image display device according to claim 7, wherein the third planar reflection surface is formed of a parallel plate, and repeats two transmissions and one reflection between optical paths from the second optical system to the secondary image surface. . Between the second optical system and the secondary image plane, a parallel parallel plate having a refractive index n is disposed,
9. The projection type image display device according to claim 1, wherein an x-axis rotation angle αt of the parallel plate is 60 ° <αt <87 °. The projection-type image display apparatus according to claim 9, wherein an openable / closable light shielding plate that shields image information from the image modulation element is disposed on the secondary image plane side of the parallel plate. The first optical system includes:
A common optical axis in which all optical components constituting the first optical system have a rotationally symmetric surface;
11. The screen shift function according to claim 1, further comprising: a screen shift function for moving the secondary image plane by movement of a part of the optical components constituting the first optical system in a direction substantially perpendicular to the optical axis. The projection-type image display device described. It has a first optical system having a positive refractive power and a second optical system having a concave reflecting surface, and is configured to enlarge and project from the primary image surface on the reduction side to the secondary image surface on the enlargement side. ,
The first optical system includes:
An eleventh optical system having a positive refractive power on the primary image plane side;
A twelfth optical system having a negative refractive power on the side of the secondary image plane from the eleventh optical system;
A first planar reflecting surface disposed between the eleventh optical system and the twelfth optical system;
Projection optical system in which the y-axis rotation angle β1 of the first plane reflection surface is 30 ° <| β1 | <65 °, and the x-axis rotation angle α1 of the first plane reflection surface is 3 ° <α1 <15 °. .

Images