JP2007272113A - Diaphragm mechanism and projection type image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm mechanism and a projection type image display device in which the form of a diaphragm aperture can be arbitrarily set. <P>SOLUTION: A projector 10 has a diaphragm mechanism comprising a liquid crystal panel 52 and a driving unit 54. The liquid crystal panel 52 comprises wire grid polarizing plates 60, 62 made of an inorganic material, a panel body 63 having pixels arranged in a matrix, and an optical compensation film 64 to prevent light leakage from the liquid crystal panel 52. The driving unit 54 controls whether or not a voltage is applied to each pixel of the liquid crystal panel 52 so as to form an aperture 70 to transmit light and a light shielding part 72 to intercept light in the liquid crystal panel 52. The form of the diaphragm aperture 70 can be easily set depending on whether or not the voltage is applied to each pixel. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projection-type image display device that modulates illumination light from an illumination optical system to generate image light, and projects the generated image light on a screen by the projection optical system, and such a projection-type image display device. The present invention relates to a diaphragm mechanism used.

  As a projection type image display device, a liquid crystal projector provided with a liquid crystal panel and a DLP (digital light processing) projector provided with a DMD (digital micromirror device) are widely known. These projection type image display devices generate image light by optically modulating illumination light from an illumination optical system by a liquid crystal panel or DMD.

  For example, in a liquid crystal projector, image light is generated by controlling the amount of illumination light transmitted through a liquid crystal panel. In addition, the DLP projector controls the reflection direction of the illumination light by the DMD, separates the illumination light into on-light that is reflected toward the projection optical system and off-light that is reflected toward the outside of the projection optical system. Image light is constituted by the set. As described above, the image light generated by the liquid crystal panel or DMD is projected on the screen by the projection optical system.

  Some projection-type image display devices include an aperture mechanism for adjusting the brightness and contrast of the projection image. As a diaphragm mechanism, there is a mechanical diaphragm mechanism that forms a circular diaphragm aperture around the optical axis by a plurality of diaphragm blades arranged around the optical axis, and switches the diaphragm aperture diameter by moving each diaphragm blade. Widely used.

There is also a diaphragm mechanism that electrically switches the diaphragm aperture diameter using a liquid crystal cell (see, for example, Patent Document 1 below). In this diaphragm mechanism, a plurality of liquid crystal cells are provided concentrically around the optical axis, and the state of each liquid crystal cell is selectively switched between a light transmitting state and a light blocking state. The diameter of the opening is electrically changed.
Japanese Patent Laid-Open No. 7-234436

  By the way, some projection-type image display devices adjust the projection position of an image by moving the projection lens in a direction perpendicular to the optical axis. In such a projection-type image display device, the pupil of the projection lens is used. When the aperture is formed at the position, it is necessary to shift the position of the aperture according to the movement of the projection lens. However, with the conventional diaphragm mechanism, the position of the diaphragm aperture cannot be shifted.

  In addition, the DLP projector has a problem that flat light reflected between the on-light and the off-light is mixed with the on-light. Since most of the flat light is mixed in a position that is biased in the off-light reflection direction, the conventional diaphragm mechanism that changes the diameter of the circular diaphragm aperture cannot prevent the influence of the flat light.

  In order to solve the above problems, an object of the present invention is to provide a diaphragm mechanism and a projection type image display apparatus that can freely set the position and shape of the diaphragm opening.

  In order to achieve the above object, a diaphragm mechanism according to the present invention is a projection-type image display device that generates image light by optically modulating illumination light from an illumination optical system and projects the image light on a screen by the projection optical system. A pair of wire grid polarizers formed on the light incident surface and the light exit surface so as to face each other in the optical axis direction, and between the wire grid polarizers A plurality of pixels arranged in a matrix in a plane parallel to the light incident surface, and the wire grid polarizing plate, and the light is inclined at an angle with respect to the optical axis. A liquid crystal panel having an optical compensation film for preventing light incident on the incident surface from leaking from the light exit surface, and driving each pixel of the liquid crystal panel, and transmitting light between the wire grid polarizers By changing the light direction, each pixel region corresponding to each pixel is characterized by comprising a panel driving means for controlling the amount of light to be transmitted through the pixel region.

  The panel driving means may form a diaphragm opening for transmitting light to the liquid crystal panel and a light shielding portion for blocking light.

  The optical compensation film is preferably an optical anisotropic film formed by laminating a plurality of materials having different refractive indexes.

  Furthermore, the optical compensation film is preferably formed from an inorganic material.

  The optical compensation film is preferably formed integrally with at least one of the wire-brid polarizing plates.

  Further, the liquid crystal panel may be a vertical alignment type liquid crystal panel or a twisted nematic type liquid crystal panel.

  Further, the aperture mechanism is disposed in the projection optical system, and the panel driving unit is configured so that the projection lens installed in the projection optical system is perpendicular to the optical axis in order to adjust the projection position of the image. When moving in the plane, the amount of light transmitted through each pixel region may be controlled along with this movement.

  Further, the panel driving means may change the position of the aperture opening that transmits light with the movement of the projection lens.

  In addition, the diaphragm mechanism includes a plurality of mirror elements arranged on an irradiation surface to which the illumination light is irradiated, an on position that reflects the illumination light toward the projection optical system, and the illumination light that is the projection optical. The panel is used in a projection-type image display device including a micromirror device that generates the image light by being displaced between an off-position that is reflected toward the outside of the system, and is disposed in the illumination optical system. The driving unit is configured to reduce the image brightness of the region where the intensity of the reflected light reflected between the on-light from the mirror element at the on-position and the off-light from the mirror element at the off-position is increased. The amount of light transmitted through the region may be controlled.

  Further, the panel driving means may change the shape of the aperture opening through which light is transmitted so that the intensity of illumination light applied to the micromirror device is non-uniform.

  The panel driving means may control the amount of light transmitted through each pixel area in accordance with the projected image.

  Further, the panel driving means may change at least one of a position and a shape of a diaphragm opening that transmits light.

  In addition, the projection type image display apparatus of the present invention is characterized by including the diaphragm mechanism as described above.

  Furthermore, in the projection type image display apparatus, it is preferable that the diaphragm mechanism is provided in at least one of the illumination optical system and the projection optical system.

  In the present invention, since a liquid crystal panel in which a plurality of pixels are arranged in a matrix is used as the diaphragm mechanism, the amount of light transmitted through each pixel region can be controlled by driving each pixel, and the position of the diaphragm aperture And shape can be set freely. In addition, since a wire grid polarizing plate formed of an inorganic material is used as the polarizing plate, for example, the polarizing plate formed of an organic material is resistant to heat and can have a long life.

  Furthermore, the liquid crystal panel has a problem in that light incident from an oblique direction leaks even if it is set to block light due to its characteristics. When used in a diaphragm mechanism as in the present invention, the light shielding portion There is a concern that if the light leaks from the lens, the function as an aperture cannot be fully achieved. On the other hand, in the present invention, an optical compensation film is provided on the liquid crystal panel to prevent light incident from an oblique direction from leaking out of the liquid crystal panel, so that the light can be reliably blocked at the light shielding portion. Further, if this optical compensation film is formed of an inorganic material, the lifetime can be further increased.

  In FIG. 1, the projector 10 of the present invention exposes the projection lens 14 on the front surface of the housing 12 by opening the lens cover when in use. A screen 15 (see FIG. 2) is disposed in front of the projection lens 14, and an image is projected from the projection lens 14. The housing 12 is provided with a zoom dial 16 and a focus dial 18, and by operating these, zooming and focusing of the projection lens 14 can be performed.

  The housing 12 is provided with a projection position adjustment dial 20 for adjusting the image projection position up and down, and a contrast adjustment dial 21 for adjusting the contrast of the projected image. By operating the projection position adjustment dial 20, the projection lens 14 is translated vertically (lens shift), and the projection position of the image is moved up and down. On the other hand, by operating the contrast adjustment dial 21, the size of a diaphragm opening 70 (see FIG. 5) described later is switched, and the contrast of the projected image changes.

  In FIG. 2, a light source 22, an illumination optical system 23, a total reflection prism 24, a DMD 26, and a projection optical system 27 are provided inside the housing 12. As the light source 22, for example, a white light source such as a xenon lamp or a mercury lamp is used. The illumination light emitted from the light source 22 enters the illumination optical system 23. The illumination optical system 23 includes a color wheel 34, a rod integrator 36, relay lenses 37 and 38, and a mirror 39, which are arranged along the optical axis 40.

  The color wheel 34 separates the illumination light from the light source 22 into R, G, and B colors in a time-sharing manner. The color wheel 34 has three color filters, an R filter that transmits only R light, a G filter that transmits only G light, and a B filter that transmits only B light, from the rotation center of the substrate. They are arranged at approximately the same distance. The color wheel 34 rotates at high speed and sequentially inserts the filters of each color into the optical axis 40. As a result, the illumination light is color-separated into three colors of R, G, and B in a time-sharing manner, and the separated light beams are sequentially emitted toward the DMD 26.

  The rod integrator 36 is made of, for example, glass, and has a reflective surface on the inside. The light separated by the color wheel 34 is averaged by repeating reflection while passing through the rod integrator 36. The relay lenses 37 and 38 relay the light beam emitted from the rod integrator 36 to the mirror 39. The mirror 39 reflects the light beam from the illumination optical system 23 toward the total reflection prism 24.

  The total reflection prism 24 is for separating incident light incident on the DMD 26 from the relay lenses 37 and 38 and reflected light reflected by the DMD 26. The total reflection prism 24 is composed of, for example, two triangular prisms having different refractive indexes, and a reflection surface 24a is formed at the boundary between the two triangular prisms. Since the incident light has an incident angle smaller than the critical angle, the incident light passes through the reflecting surface 24 a and enters the DMD 26. On the other hand, the reflected light reflected by the DMD 26 is totally reflected by the reflecting surface 24a because the incident angle is larger than the critical angle.

  As is well known, the DMD 26 has a large number of mirror elements corresponding to the pixels arranged in a matrix behind the cover glass 26a. Each mirror element changes the reflection direction of the received illumination light by changing the angle based on the projected image. When displaying a pixel brightly, the mirror element is displaced to the ON position, and the received light is reflected toward the projection optical system 27 as ON light. On the other hand, when the pixel is displayed darkly, the mirror element is displaced to the off position, and the received light is reflected in the direction away from the projection optical system 27 as off light. The image light is constituted by a set of on-lights directed toward the projection optical system 27.

  The image light is preferably composed only of the above-mentioned on-light. However, if off-light is irregularly reflected in the housing 12 and mixed with the on-light, the quality of the projected image is deteriorated. For this reason, a light absorbing member 41 is provided between the projection optical system 27 and the total reflection prism 24. The light absorbing member 41 is, for example, a black cloth disposed on a plate, and absorbs off-light emitted from the total reflection prism 24. This prevents the problem that off-light is irregularly reflected in the housing 12 and mixed with the on-light, resulting in a deterioration in the quality of the projected image.

  The projection optical system 27 includes a projection lens 14 including a plurality of lenses, and a lens moving mechanism 43 that moves the projection lens 14. The lens moving mechanism 43 moves the projection lens 14 along the optical axis 40 for zooming and focus adjustment, and moves the projection lens 14 in a direction perpendicular to the optical axis 40 during the lens shift described above. The image light generated by the DMD 26 is imaged on the screen 15 by the projection optical system 27.

  Further, the projector 10 is provided with a diaphragm mechanism 50 between the relay lens 38 and the mirror 39. As shown in FIG. 3, the aperture mechanism 50 includes a liquid crystal panel 52 and a drive unit 54 that drives the liquid crystal panel 52, and the liquid crystal panel 52 further includes wire grid polarizers 60 and 62 and a panel body 63. And the optical compensation film 64.

  The wire grid polarizers 60 and 62 are disposed on the light incident surface 52a on the front side and the light emitting surface 52b on the back side of the liquid crystal panel 52, respectively. The wire grid polarizers 60 and 62 are formed by arranging a plurality of wires formed of an inorganic material in parallel and transmit only light having a polarization direction parallel to the longitudinal direction of the wires. The wire grid polarizers 60 and 62 are arranged in a crossed Nicol arrangement in which the other is rotated 90 degrees with respect to one so that the polarization direction of light to be transmitted (longitudinal direction of the wire) is orthogonal. Since the projector uses a light source with a large amount of light, the optical system components become high temperature, but the durability can be improved compared to the case where an organic material is used by forming a polarizing plate using an inorganic material. .

  The panel body 63 has liquid crystal molecules sealed between a pair of transparent substrates, and is disposed between the wire grid polarizers 60 and 62. The panel body 63 has a plurality of pixels arranged in a matrix in a plane perpendicular to the optical axis 40.

  In the present embodiment, a twisted nematic liquid crystal panel is used as the liquid crystal panel 52. Thus, in a state where no voltage is applied to the pixels, the liquid crystal molecules are twisted between the transparent substrates, and the light incident from the wire grid polarizer 60 is rotated by 90 degrees while passing through the pixels. The light is emitted from the wire grid polarizer 62 as it is. On the other hand, when a voltage is applied to the pixel, the twist alignment of the liquid crystal molecules is lost. For this reason, the light incident from the wire grid polarizer 60 is not rotated in the polarization direction when passing through this pixel, and cannot pass through the wire grid polarizer 62.

  In the aperture mechanism 50, the aperture opening 70 (see FIG. 5) is configured by a set of regions corresponding to pixels to which no voltage is applied in the liquid crystal panel 52, that is, a set of regions where incident light is emitted as it is. . Further, in the liquid crystal panel 52, a set of regions corresponding to pixels to which a voltage is applied, that is, a set of regions where incident light is blocked constitutes the light shielding unit 72 (see FIG. 5). In the present invention, since a plurality of pixels are arranged in a matrix in the panel body 63, the shape of the aperture opening 70 is changed by an electrical process such as determining whether to apply a voltage for each pixel. It can be set to any shape.

  However, even if a voltage is applied to the pixel so that the light cannot pass through the liquid crystal panel 52, there is a problem that light incident from an oblique direction with respect to the optical axis 40 leaks from the liquid crystal panel 52. Therefore, in the present invention, the optical compensation film 64 for preventing light incident from the oblique direction with respect to the optical axis 40 from leaking from the liquid crystal panel 52 between the panel body 63 and the wire grid polarizer 62. Is provided. The optical compensation film 64 is an optically anisotropic film having a laminated structure in which materials having different refractive indexes are periodically stacked. For example, by directly laminating the material on the wire grid polarizer 62, a wire is obtained. It is formed integrally with the grid polarizer 62.

  As a result of an experiment using such an optical compensation film 64, when the optical compensation film 64 is provided as shown in FIG. 4A, the optical compensation film 64 shown in FIG. 4B is not provided. Compared with the case, it was confirmed that the light leaking from the liquid crystal panel 52 can be significantly suppressed. More specifically, the optical compensation film 64 is described in, for example, Japanese Patent Application Laid-Open Nos. 2005-62671, 2005-62672, 2005-62673, and 2005-292781. Things can be used.

  Although the present invention is not limited by the material constituting the optical compensation film 64, it is preferable that the optical compensation film 64 is composed of an inorganic material in consideration of durability. Further, the example in which the optical compensation film 64 is provided between the panel body 56 and the wire grid polarizer 62 has been described, but the optical compensation film 64 may be provided between the panel body 56 and the wire grid polarizer 60. . Of course, the optical compensation film 64 may be provided on both of them.

  The liquid crystal panel 52 is driven and controlled by a driving unit 54. The drive unit 54 is connected to the panel main body 63 and controls whether or not a voltage is applied to each pixel, whereby the liquid crystal panel 52 has a diaphragm opening 70 and a light shielding as shown in FIG. Part 72 is formed. In the present embodiment, the drive unit 54 forms the aperture opening 70 having a shape in which two portions of the circle are cut out by straight lines. This cut-out portion is for preventing the influence of the flat light reflected between the on-light and the off-light, and reduces the illumination light irradiated to the portion where the image brightness is increased by the flat light in advance. It has a function.

  Further, the drive unit 54 enlarges the size of the aperture opening 70 as shown in FIG. 5B or the aperture opening as shown in FIG. 5C according to the operation of the contrast adjustment dial 21. The size of 70 is reduced. As a result, the contrast of the projected image changes. As described above, in the projector 10, the shape of the aperture opening 70 can be freely set by electrical processing. Therefore, the aperture opening 70 other than the circular shape described above can be formed, or the size of the aperture opening 70 can be set. It is easy to change.

  The shape of the aperture opening is not currently the shape described in the above embodiment, and may be changed as appropriate. In this case, for example, it is conceivable to analyze the pattern or scene of the projected image and change the shape of the aperture opening so as to be optimal for the pattern or scene of each image based on the analysis result. Further, for example, a plurality of projection modes such as a movie watching mode, a sports watching mode, and a game mode may be provided, and the shape of the aperture opening may be changed so as to be optimal in each mode. In the present invention, the shape of the aperture opening can be easily and quickly changed to an arbitrary shape by electrical processing. Therefore, as described above, the shape of the aperture opening can be changed to a projected image pattern, scene, projection mode, etc. Accordingly, when the shape is changed to various shapes, a more remarkable effect can be obtained.

  Moreover, although the said embodiment demonstrated the example which arrange | positions an aperture mechanism in an illumination optical system, this invention is not limited to this. For example, a diaphragm mechanism 150 may be arranged in the projection optical system 27 as in the projector 100 shown in FIG. In the explanation using Drawings after Drawing 6, the same numerals are given about the same member as an embodiment mentioned above, and explanation is omitted.

  In FIG. 6, the projector 100 is provided with a diaphragm mechanism 150 including the liquid crystal panel 52 similar to the above-described embodiment at the pupil position of the projection lens 14. The diaphragm mechanism 150 changes the size of the diaphragm opening 70 according to the operation of the contrast adjustment dial 21 as in the above embodiment. Further, when the projection position adjustment dial 20 is operated and the projection lens 14 is shifted, the aperture mechanism 150 moves the position of the aperture opening 70 according to the position of the movement destination of the projection lens 14. .

  At this time, the diaphragm mechanism 150 moves the diaphragm opening 70 so that the optical axis 40 always passes through the center of the diaphragm opening 70. That is, when the projection lens 14 is not moved, since the optical axis 40 passes through the center of the liquid crystal panel 52, the aperture opening 70 is formed at the center of the liquid crystal panel 52 as shown in FIG.

  Further, when the projection lens 14 is moved upward in FIG. 7, the optical axis 40 is moved upward from the center of the liquid crystal panel 52 along with this movement, so that the diaphragm mechanism 150 is shown in FIG. As described above, the position of the aperture opening 70 is moved above the center of the liquid crystal panel 52. Further, when the projection lens 14 is moved downward in FIG. 7, the optical axis 40 moves downward from the center of the liquid crystal panel 52, so that the aperture mechanism 150 is configured as shown in FIG. The position of the aperture opening 70 is moved below the center of the liquid crystal panel 52.

  If the optical axis 40 does not pass through the center of the aperture 70, the light that should be shielded cannot be shielded in part, and the image light that is to be projected is shielded on the other hand, resulting in uneven brightness in the projected image. However, in the projector 100, the diaphragm opening 70 is always formed around the optical axis 40, and thus there is no such problem. Further, according to the present invention, the position of the aperture opening 70 can be easily moved by electrical processing.

  In this example, the example of forming the circular aperture opening has been described. However, as in the above embodiment, the aperture aperture having a shape in which a part of the circle is notched is formed, and due to the influence of flat light, You may reduce the image light of the part where image brightness becomes bright. Of course, you may form the aperture opening of shapes other than these. Further, a projection mechanism may be provided in the projection optical system as in this example, and a diaphragm mechanism may be provided in the illumination optical system as in the above embodiment to constitute a projector having two diaphragm mechanisms.

  Further, in the above-described embodiment, the description has been given of the example in which the incident light is switched in two steps, that is, whether the incident light is totally transmitted or completely blocked, but the present invention is not limited to this. By adjusting the magnitude of the voltage applied to each pixel, the amount of light transmitted through the region corresponding to each pixel may be switched in a stepwise manner between total transmission and total blocking.

  Thus, if the transmitted light amount is switched stepwise between total transmission and total blocking, the intensity distribution of the light emitted from the aperture mechanism in the exit plane can be freely adjusted. Thereby, for example, when the intensity distribution of the light incident on the aperture mechanism in the incident surface is non-uniform, it can be made uniform and emitted. In addition, when the illumination light applied to the portion where the image brightness increases due to the flat light is reduced in advance, the amount of light transmitted through each pixel region can be adjusted according to the amount of the flat light mixed in. In addition, the influence of flat light can be prevented. Furthermore, the amount of light transmitted through each pixel region can be adjusted so as to be optimal for the pattern or scene of the projected image.

  In the above embodiment, the example in which the diaphragm mechanism is configured using a twisted nematic (TN) type liquid crystal panel has been described. However, the diaphragm mechanism may be configured using a vertical alignment (VA) type liquid crystal panel. Good. In the above embodiment, an example in which the present invention is applied to a DLP projector has been described. However, the present invention is not limited to this. The present invention may be applied to a projector other than a DLP projector, such as a liquid crystal projector.

It is an external view of a projector. It is a block diagram of a projector. It is a block diagram of an aperture mechanism. It is explanatory drawing showing a mode that the light which leaks by an optical compensation film reduces. It is explanatory drawing showing an aperture opening part. It is a block diagram of a projector. It is explanatory drawing showing an aperture opening part.

Explanation of symbols

10, 100 Projector 14 Projection lens 23 Illumination optical system 26 DMD
27 Projection optical system 40 Optical axis 43 Lens moving mechanism 50, 150 Aperture mechanism 52 Liquid crystal panel 54 Drive unit 60, 62 Wire grid polarizer 63 Panel body 64 Optical compensation film 70 Aperture aperture 72 Light shielding unit

Claims (15)

In a diaphragm mechanism used in a projection-type image display device that modulates illumination light from an illumination optical system to generate image light and projects this image light on a screen by a projection optical system.
A pair of wire grid polarizers that are formed of an inorganic material and are disposed on each of the light incident surface and the light exit surface so as to face each other in the optical axis direction, and a plurality of pixels disposed between the wire grid polarizers. A liquid crystal panel main body arranged in a matrix in a plane parallel to the light incident surface, and the wire grid polarizing plate, and light incident on the light incident surface at an angle inclined with respect to the optical axis A liquid crystal panel having an optical compensation film for preventing leakage from the light exit surface;
A panel that controls the amount of light transmitted through the pixel area for each pixel area corresponding to each pixel by driving each pixel of the liquid crystal panel and changing the polarization direction of the light between the wire grid polarizers. And an aperture mechanism.   2. The diaphragm mechanism according to claim 1, wherein the panel driving unit forms a diaphragm opening for transmitting light to the liquid crystal panel and a light shielding part for blocking light.   3. The aperture mechanism according to claim 1, wherein the optical compensation film is an optical anisotropic film formed by laminating a plurality of materials having different refractive indexes.   The diaphragm mechanism according to claim 1, wherein the optical compensation film is made of an inorganic material.   The diaphragm mechanism according to any one of claims 1 to 4, wherein the optical compensation film is formed integrally with at least one of the wire-brid polarizing plates.   6. The aperture mechanism according to claim 1, wherein the liquid crystal panel is a vertical alignment type liquid crystal panel.   The diaphragm mechanism according to any one of claims 1 to 5, wherein the liquid crystal panel is a twisted nematic liquid crystal panel. The aperture mechanism is disposed in the projection optical system,
When the panel driving unit moves the projection lens installed in the projection optical system within a plane perpendicular to the optical axis in order to adjust the projection position of the image, each pixel is moved along with this movement. The diaphragm mechanism according to any one of claims 1 to 7, wherein the amount of light transmitted through the region is controlled.   9. The diaphragm mechanism according to claim 8, wherein the panel driving unit changes a position of a diaphragm opening through which light is transmitted in accordance with the movement of the projection lens. The diaphragm mechanism includes: an on position that reflects the illumination light toward the projection optical system; and a plurality of mirror elements arranged on an irradiation surface that is irradiated with the illumination light; and the illumination light is out of the projection optical system. It is used in a projection-type image display device provided with a micromirror device that generates the image light by being displaced between an off-position that reflects toward the screen, and is disposed in the illumination optical system.
The panel driving means lowers the image brightness in a region where the intensity of reflected light reflected between the on-light from the mirror element at the on-position and the off-light from the mirror element at the off-position increases. The diaphragm mechanism according to claim 1, wherein the amount of light transmitted through each pixel region is controlled.   The diaphragm mechanism according to claim 10, wherein the panel driving unit changes the shape of a diaphragm opening that transmits light so that the intensity of illumination light applied to the micromirror device is nonuniform.   The diaphragm mechanism according to claim 1, wherein the panel driving unit controls the amount of light transmitted through each pixel region in accordance with a projected image.   The diaphragm mechanism according to claim 12, wherein the panel driving unit changes at least one of a position and a shape of a diaphragm opening that transmits light.   A projection-type image display device comprising the aperture mechanism according to claim 1.   15. The projection type image display device according to claim 14, wherein the diaphragm mechanism is provided in at least one of the illumination optical system and the projection optical system.

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