JP2009086400A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector, achieving high-quality image projection by reducing contrast unevenness with a relatively simple structure. <P>SOLUTION: When an illuminating light which is not perfectly uniformed is incident on a liquid crystal panel 41a by diffusing effect of a light diffusion member 44a disposed in a stage prior to the liquid crystal panel 41a, the range or distribution of incident angle of the light is properly uniformed. Accordingly, the contrast unevenness resulting from non-uniform illuminating light can be reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projector that illuminates a liquid crystal panel or the like with an illumination optical system and projects an image of the liquid crystal panel or the like.

  As a projector using a conventional liquid crystal panel, in order to improve contrast and reduce color unevenness, a projector that can rotate the polarizing plate disposed on the exit side or the incident side of the liquid crystal panel, or the light of the liquid crystal panel One in which an optical compensation film is installed on the emission side or the light incident side is known (see Patent Document 1).

It is generally known that a microlens array in which lenses are arranged in accordance with individual pixels of a liquid crystal display panel is arranged in order to increase the light utilization efficiency (see, for example, Patent Document 2). .
JP-A-2005-107364 JP 2000-147500 A

  However, in general, illumination light does not become completely uniform due to various restrictions on the design of the projector, and this may cause unevenness in contrast. In such a case, for example, even if an optical compensation film or the like is provided on the light emitting side or the light incident side of the liquid crystal panel, the contrast of the projected image is not always improved.

  Therefore, an object of the present invention is to provide a projector that can perform high-quality image projection by reducing contrast unevenness while having a relatively simple structure.

  In order to solve the above problems, a projector according to the present invention includes (a) an illumination device that uniformizes light from a light source to form illumination light, and (b1) liquid crystal that is illuminated by illumination light from the illumination device. A device, (b2) a polarizing plate that is arranged in front of the liquid crystal device and adjusts the polarization direction of the illumination light incident on the liquid crystal device, and (b3) an illumination light that is arranged between the polarizing plate and the incident surface of the liquid crystal device. A light modulation device having a light diffusion member that diffuses; and (c) a projection optical system that projects image light that has passed through the light modulation device.

  In the projector described above, the illumination light from the illumination device can be diffused to a desired degree in the vicinity of the previous stage on the optical path of the liquid crystal device by a simple light diffusion member. Thereby, the incident angle of the illumination light to the liquid crystal device is made uniform, and the contrast unevenness can be reduced. Here, the “light diffusing member” includes, for example, a member that imparts a light diffusing function to the polarizing plate by processing a part of the polarizing plate.

  As a specific aspect of the present invention, the light diffusing member is disposed apart from the liquid crystal device. In this case, the light diffusing member is adjusted to an appropriate position separated from the liquid crystal device so that the incident angle and illuminance distribution of the illumination light diffused by the light diffusing member can be made uniform in the liquid crystal device.

  Further, as a specific aspect of the present invention, a light diffusing member is attached to the exit surface side of the polarizing plate. Thereby, a light-diffusion member can be handled integrally with a polarizing plate.

  As a specific aspect of the present invention, the light diffusing member is configured by a multi-lens array in which a plurality of small lenses are arranged in a planar shape. In this case, the state of the illumination light when entering the liquid crystal device can be appropriately diffused by a plurality of small lenses arranged in a plane.

  As a specific aspect of the present invention, the multi-lens array has a plurality of small lenses arranged at random. In this case, the illumination light can be uniformly diffused without causing a bias in the diffusion of the entire multi-lens array.

  As a specific aspect of the present invention, (a) a liquid crystal device has a plurality of liquid crystal cells arranged in a plane with a predetermined pattern, and (b) a plurality of small lenses has a pattern different from the predetermined pattern. It is arranged with. In this case, the multilens array can be manufactured at a relatively low cost without making the pitch of the small lenses of the multilens array correspond to the alignment pattern of the liquid crystal cells of the liquid crystal device.

  Moreover, as a specific aspect of the present invention, the light diffusing member is configured by forming random irregularities on the surface existing from the polarizing plate to the incident surface of the liquid crystal device. Thereby, a diffusion effect can be caused by random irregularities formed on the surface.

  Moreover, as a specific aspect of the present invention, the light diffusing member is a sheet having a portion that diffuses light inside or on the surface. In this case, the illumination light can be diffused in an appropriate state by a sheet that can be pasted for adjustment.

  Hereinafter, a structure and the like of a projector according to an embodiment of the invention will be described along the system optical axis with reference to the drawings.

  FIG. 1 is a conceptual diagram for explaining the structure of the projector according to the present embodiment. The projector 200 according to this embodiment includes a light source device 10, an illumination optical system 20, a color separation optical system 30, a light modulation unit 40, a cross dichroic prism 50, and a projection lens 60 along the system optical axis OA. Is provided.

  In the projector 200, the light source device 10 includes an arc tube 11 and a reflector 12, and emits illumination light for illuminating the liquid crystal light valves 40a, 40b, and 40c of the light modulation unit 40 via the illumination optical system 20 and the like. appear.

  The illumination optical system 20 includes a collimating lens 22 that is a light collimating unit that collimates the light beam direction of the light source light, and first and second fly-eye lenses that constitute an integrator optical system for dividing and superimposing light. 23a, 23b, a polarization conversion element 24 that aligns the polarization direction of light, a superimposing lens 25 that superimposes light that has passed through both fly-eye lenses 23a, 23b, and a mirror 26 that bends the optical path of the light. The substantially white illumination light is formed. In the illumination optical system 20, the collimating lens 22 converts the light beam direction of the illumination light emitted from the light source device 10 to be substantially parallel. The first and second fly-eye lenses 23a and 23b are each composed of a plurality of element lenses arranged in a matrix, and the light that has passed through the collimating lens 22 is divided by the element lenses constituting the first fly-eye lens 23a. The light beams are individually condensed, and the divided light beams from the first fly-eye lens 23a are emitted with an appropriate divergence angle by the element lenses constituting the second fly-eye lens 23b. The polarization conversion element 24 is formed of an array having a PBS, a mirror, a retardation plate, etc. as a set of elements, and the polarization direction of each partial light beam divided by the first fly-eye lens 23a is linearly polarized in one direction. It has a role to align. The superimposing lens 25 appropriately converges the illumination light that has passed through the polarization conversion element 24 as a whole, and enables superimposing illumination on the illuminated areas of the liquid crystal light valves 40a, 40b, and 40c, which are the light modulation devices of the subsequent stages.

  The color separation optical system 30 includes first and second dichroic mirrors 31a and 31b, reflection mirrors 32a, 32b, and 32c, and three field lenses 33a, 33b, and 33c, and is made uniform by the illumination optical system 20. The illumination light is separated into three colors of red (R), green (G), and blue (B), and each color light is guided to the liquid crystal light valves 40a, 40b, and 40c at the subsequent stage. More specifically, first, the first dichroic mirror 31a transmits R light and reflects G light and B light among the three colors of RGB. The second dichroic mirror 31b reflects G light and transmits B light out of the two colors of GB. In the color separation optical system 30, the R light transmitted through the first dichroic mirror 31a enters the field lens 33a for adjusting the incident angle through the reflection mirror 32a. Further, the G light reflected by the first dichroic mirror 31a and further reflected by the second dichroic mirror 31b is incident on the field lens 33b for adjusting the incident angle. Further, the B light that has passed through the second dichroic mirror 31b enters the field lens 33c for adjusting the incident angle via the relay lenses LL1 and LL2 and the reflection mirrors 32b and 32c.

  The light modulator 40 includes liquid crystal light valves 40a, 40b, and 40c that are non-light-emitting and transmissive light modulators. The liquid crystal light valves 40a, 40b, and 40c are three liquid crystal panels 41a, 41b, and 41c, which are liquid crystal devices that are illuminated corresponding to the respective color lights emitted from the color separation optical system 30, and the liquid crystal panels 41a, 40b. , 41c, respectively, three first polarizing plates 42a, 42b, 42c, and three second polarizing plates 43a, 43b, 43c respectively arranged on the exit side of the liquid crystal panels 41a, 41b, 41c. And light diffusion members 44a, 44b, 44c attached to the back surfaces of the three first polarizing plates 42a, 42b, 42c, that is, the surfaces on the light emission side. The R light transmitted through the first dichroic mirror 31a enters the liquid crystal light valve 40a via the field lens 33a and the like, and illuminates the liquid crystal panel 41a of the liquid crystal light valve 40a. The G light reflected by both the first and second dichroic mirrors 31a and 31b is incident on the liquid crystal light valve 40b via the field lens 33b and the like, and illuminates the liquid crystal panel 41b of the liquid crystal light valve 40b. The B light reflected by the first dichroic mirror 31a and transmitted through the second dichroic mirror 31b enters the liquid crystal light valve 40c through the field lens 33c and the like, and illuminates the liquid crystal panel 41c of the liquid crystal light valve 40c. Each of the liquid crystal panels 41a to 41c modulates the spatial intensity distribution in the polarization direction of the incident illumination light, and the three colors of light incident on the liquid crystal panels 41a to 41c are electrically transmitted to the liquid crystal panels 41a to 41c. The polarization state is adjusted in units of pixels in accordance with the drive signal or image signal input as. At this time, the polarization direction of the illumination light incident on the liquid crystal panels 41a to 41c is adjusted by the first polarizing plates 42a to 42c, and the illumination light is appropriately diffused by the light diffusion members 44a, 44b, and 44c. . Further, modulated light having a predetermined polarization direction is extracted from the modulated light emitted from the liquid crystal panels 41a to 41c by the second polarizing plates 43a to 43c. As described above, the liquid crystal light valves 40a, 40b, and 40c of the light modulation unit 40 form image light of the corresponding colors.

  The cross dichroic prism 50 combines the image light of each color formed by the light modulator 40. More specifically, the cross dichroic prism 50 has a substantially square shape in plan view in which four right angle prisms are bonded together, and a pair of dielectric multilayer films intersecting in an X shape at the interface where the right angle prisms are bonded to each other. 51a and 51b are formed. One first dielectric multilayer film 51a reflects R light, and the other second dielectric multilayer film 51b reflects B light. The cross dichroic prism 50 reflects the R light from the liquid crystal light valve 40a by the dielectric multilayer film 51a and emits the G light from the liquid crystal light valve 40b through the dielectric multilayer films 51a and 51b. The B light from the liquid crystal light valve 40c is reflected by the dielectric multilayer film 51b and emitted to the left in the traveling direction. In this way, R light, G light, and B light are combined by the cross dichroic prism 50.

  The projection lens 60 is a projection optical system, and projects the color image on a screen (not shown) by enlarging the image light by the combined light formed through the cross dichroic prism 50 with a desired magnification.

  FIG. 2 is a cross-sectional view conceptually illustrating the configuration of the liquid crystal light valve 40a constituting the projector 200 of FIG.

  As described above, the liquid crystal light valve 40a includes the first polarizing plate 42a, the light diffusion member 44a, the liquid crystal panel 41a, and the second polarizing plate 43a in the order of the optical path of the system optical axis OA. Each member constituting the liquid crystal light valve 40a is integrally fixed by a holder HD.

  Among these, first, the first polarizing plate 42a is configured by attaching an incident polarizing filter IF having a property of transmitting only light in a specific polarization direction to the surface IS on the light incident side of the surface of the glass substrate GB. Has been. The first polarizing plate 42a maintains a predetermined positional relationship with the liquid crystal panel 41a by fixing using the holder HD.

  Next, the light diffusing member 44a is a multi-lens array in which a plurality of minute small lenses LA are arranged in a planar shape. Here, the plurality of small lenses LA are sufficiently small to uniformly diffuse the illumination light. The light diffusing member 44a is a plate or sheet integrally formed by, for example, injection molding a transparent organic material, and is attached to the back surface of the glass substrate GB of the first polarizing plate 42a, that is, the surface ES on the light emitting side. It has been. Thereby, the 1st polarizing plate 42a and the light-diffusion member 44a are handled as one component integrated. Here, the illumination light transmitted through the light diffusing member 44a is divided and uniformly diffused by each small lens LA. That is, the direction of the illumination light having a certain degree of directionality, that is, bias in the traveling direction, is random. As a result, the incident angle of the illumination light is averaged as a whole.

  With the structure as described above, the polarization direction of the illumination light incident on the liquid crystal light valve 40a is first adjusted by the incident polarizing filter IF of the first polarizing plate 42a out of the first polarizing plate 42a and the light diffusing member 44a. Next, the light is diffused moderately by the light diffusion member 44a attached to the light exit side of the first polarizing plate 42a.

  The liquid crystal panel 41a disposed at the subsequent stage of the first polarizing plate 42a incorporates a liquid crystal cell layer CL composed of a liquid crystal cell as a display pixel that modulates incident illumination light, and the liquid crystal cell layer CL provides a liquid crystal cell unit. Light modulation is performed at Accordingly, the illumination light emitted from the light diffusion member 44a is optically modulated by the liquid crystal panel 41a in units of liquid crystal cells, that is, in units of pixels.

  The second polarizing plate 43a disposed at the rear stage of the liquid crystal panel 41a has an emission polarizing filter EF having a property of transmitting only light of a specific polarization direction on the back surface of the glass substrate GB, that is, the surface ES on the light emission side. It is composed of that. Here, the incident polarizing filter IF of the first polarizing plate 42a and the outgoing polarizing filter EF of the second polarizing plate 43a are arranged, for example, in a crossed Nicol state in which the polarization directions are orthogonal. Of the light emitted from the liquid crystal panel 41, only light having a component in a specific direction necessary for image projection is extracted as modulated light by the exit polarizing filter EF.

  As described above, image light is formed by the liquid crystal light valve 40a. In this case, illumination light that is not completely uniform is applied to the liquid crystal panel 41 by the diffusing action of the light diffusion member 44a. When incident, the incident angle of light is appropriately uniformized. As a result, it is possible to reduce the unevenness in contrast caused by uneven illumination light. Here, the light diffusion member 44a is disposed at the position of the first polarizing plate 42a relatively close to the liquid crystal panel 41a, and can prevent the illumination light from being diffused more than necessary before entering the liquid crystal panel 41a. .

  Here, the plurality of small lenses LA in FIG. 2 need only be sufficiently small to diffuse the illumination light, and need not necessarily be arranged regularly. For example, by arranging each small lens LA at random within an appropriate range, it is possible to achieve uniform diffusion as a whole with no bias by making the diffusion action not regular. It is also possible to control the range and distribution of the incident angle of the illumination light in the liquid crystal panel 41a to a desired state by appropriately adjusting the lens shape and arrangement pattern of each lens LA.

  The details of the structure of the liquid crystal light valves 40b and 40c shown in FIG. 1 are the same as those of the liquid crystal light valve 40a shown in FIG. Therefore, although the description of the liquid crystal light valves 40b and 40c is omitted, the formation of image light in the liquid crystal light valves 40b and 40c is performed in the same manner as in the case of the liquid crystal light valve 40a. It is formed.

  FIGS. 3A and 3B are diagrams showing the distribution of incident angles on the liquid crystal panel in the projector according to the present embodiment. FIG. 3C is a diagram showing contrast characteristics with respect to the incident angle of light of the liquid crystal panel. FIG. 3A is a diagram showing the distribution of the incident angle at the central portion of the incident surface of the liquid crystal panel, and FIG. 3B is the peripheral portion of the incident surface of the liquid crystal panel (for example, the four corners of the liquid crystal panel). It is a figure which shows distribution of the incident angle in the upper right side). In each figure, the center part of each figure indicates the amount of light incident vertically, and the amount of light incident at an incident angle that is greatly inclined toward the periphery. In the case of the projector according to the present embodiment, the distribution of the incident angle for the central portion and the distribution of the incident angles for the peripheral portion are equalized in a substantially concentric manner. That is, the incident angle of light is appropriately uniformized. In general, the liquid crystal panel has contrast characteristics depending on the incident angle as shown in FIG. 3C with respect to the incident angle of light. For this reason, if there is a difference in the distribution of the incident angle between the central portion and the peripheral portion of the panel, unevenness of the contrast will be caused. However, in this embodiment, the incident angle of light is appropriately uniformed as described above. Thus, the occurrence of unevenness in contrast can be reduced.

  FIGS. 4A and 4B are graphs showing the distribution of the incident angle to the liquid crystal panel and the contrast characteristics in the projector of the comparative example. 4A and 4B are diagrams showing the distribution of incident angles on the liquid crystal panel when the light diffusing member such as the light diffusing member 44a is not provided in the projector 200 according to the present embodiment. FIG. 4A is a diagram showing the distribution of the incident angle at the central portion of the incident surface of the liquid crystal panel, and FIG. 4B is the peripheral portion of the incident surface of the liquid crystal panel (for example, the four corners of the liquid crystal panel). It is a figure which shows distribution of the incident angle in the upper right side). In this case, the distribution of the incident angle of light at the central portion of the incident surface of the liquid crystal panel is relatively balanced as shown in FIG. As shown in FIG. 4B, for example, the left and right balance is poor. That is, in this case, the projection image has uneven contrast between the central portion and the peripheral portion of the image. This can also cause uneven color.

  FIG. 5 is a diagram for explaining a modification of the light modulation device. Compared with FIG. 2, the liquid crystal light valve 40a which is the light modulation device of this modification is obtained by replacing the installation positions of the incident polarization filter IF and the light diffusion member 44a. In other words, in the liquid crystal light valve 40a of the present modification, the first polarizing plate 42a is configured by attaching the incident polarizing filter IF to the surface ES on the light emission side of the glass substrate GB, and the light incident on the glass substrate GB. A light diffusion member 44a is attached to the surface IS on the side. Thereby, the 1st polarizing plate 42a and the light-diffusion member 44a are handled as one component integrated. In this case, the illumination light incident on the liquid crystal light valve 40a is first appropriately diffused by the light diffusion member 44a. The illumination light in a properly diffused state is transmitted through the glass substrate GB, only the light having a specific polarization direction is transmitted through the incident polarization filter IF, and is emitted toward the liquid crystal panel 41a at the subsequent stage.

  FIG. 6A and FIG. 6B are diagrams for explaining another modification of the light modulation device. Among the light modulation devices of this modification, the liquid crystal light valve 40a shown in FIG. 6A has a surface on the back side of the glass substrate GB constituting the first polarizing plate 42a which is a polarizing plate on the incident side, that is, a light emitting side. A random uneven surface ES (RS) is formed on the surface ES by blasting or etching. In this case, the uneven surface RS formed on the glass substrate GB has a diffusing function. That is, as a result, the glass substrate GB having the uneven surface RS functions as a light diffusing member. Therefore, in this case, the illumination light can be appropriately diffused without using the light diffusing member 44a shown in FIG.

  Further, as shown in FIG. 6B, a diffusion sheet DS may be attached to the surface ES on the light emission side of the glass substrate GB constituting the first polarizing plate 42a. In this case, the diffusion sheet DS functions as a light diffusion member. In this case, for example, the diffusion sheet DS can be attached later for adjustment.

  6A and 6B, as in the case shown in FIG. 5, the incident polarizing filter IF is applied to the surface ES on the light emission side of the glass substrate GB constituting the first polarizing plate 42a. It is also possible to provide a concavo-convex surface RS or a diffusing sheet DS which is stuck and produces a diffusing action on the surface IS on the light incident side.

  FIG. 7A and FIG. 7B are diagrams for explaining still another modification of the light modulation device. Among the light modulation devices of the present modification, in the liquid crystal light valve 40a shown in FIG. 7A, the light diffusing member 44a is provided at a stage after the first polarizing plate 42a by the holder HD independently of the first polarizing plate 42a. It is fixed to the front stage of the liquid crystal panel 41a. That is, the light diffusing member 44a is disposed away from both the liquid crystal panel 41a and the first polarizing plate 42a. In this case, for example, the illumination light can be diffused at a position closer to the liquid crystal panel 41a than in the case shown in FIG. Further, the position after the first polarizing plate 42a and the front stage of the liquid crystal panel 41a, that is, the distance setting from the light diffusion member 44a to the liquid crystal panel 41a is set according to the optical design, the nature of the light diffusion member used, etc. It is also possible to adjust appropriately. By appropriately adjusting the position, the state of illumination light incident on the liquid crystal panel 41a can be made more suitable.

  Moreover, as shown in FIG.7 (b), it is good also as a structure which sticks the light-diffusion member 44a on the entrance plane of the liquid crystal panel 41a. In this case, light diffusion can be performed in the immediate vicinity of the liquid crystal panel 41a. In this case, for example, the plurality of small lenses LA constituting the light diffusing member 44a only have to exhibit a diffusion effect, and are not so precise that a specific small lens corresponds to a specific liquid crystal cell. Good. Therefore, for example, the arrangement of the plurality of small lenses LA may be a pattern different from the arrangement pattern of the liquid crystal cells in the liquid crystal panel 41a, such as being randomly arranged within an appropriate range.

  In the example shown in FIGS. 7A and 7B, the light diffusing member 44a is configured by a multi-lens array. However, the light diffusing member 44a is not limited to this, for example, random unevenness. It may be ground glass having a surface or a glass substrate having a diffusion sheet attached thereto. Further, as shown in FIG. 8, a random uneven surface RS may be formed on the surface of the liquid crystal panel 41a, that is, the incident surface. That is, in this case, the uneven surface RS that is the surface portion of the liquid crystal panel 41a functions as a light diffusing member.

  In addition, this invention is not restricted to said embodiment, In the range which does not deviate from the summary, it can implement in a various aspect, For example, the following deformation | transformation is also possible.

  First, various lamps such as a high-pressure mercury lamp and a metal halide lamp are conceivable as lamps used for the arc tube 11 incorporated in the light source device 10.

  Further, in the projector 200 of the above embodiment, a pair of fly-eye lenses 23a and 23b is used to divide the light from the light source device 10 into a plurality of partial light beams. That is, the present invention can be applied to a projector that does not use a lens array. Further, the fly-eye lenses 23a and 23b can be replaced with rod integrators.

  Further, although the projector 200 uses the polarization conversion element 24 that converts the light from the light source device 10 into a specific direction of polarization, the present invention is also applicable to a projector that does not use such a polarization conversion element 24. is there.

  The projector includes a front projector that projects an image from the direction of observing the projection surface and a rear projector that projects an image from the side opposite to the direction of observing the projection surface. The projector configuration shown in FIG. Is applicable to both.

  In the above-described embodiment, only the example of the projector 200 using the three liquid crystal panels 41a to 41c has been described. However, the present invention is a projector using only one liquid crystal panel, a projector using two liquid crystal panels, Or it is applicable also to the projector using four or more liquid crystal panels.

It is a conceptual diagram explaining the projector which concerns on one Embodiment of this invention. It is a conceptual diagram explaining an optical modulation apparatus. (A), (b), (c) is a figure of the incident angle distribution to the liquid crystal device of illumination light. (A), (b) is a comparative example of the incident angle distribution to the liquid crystal device of illumination light. It is a conceptual diagram explaining the modification of a light modulation apparatus. It is a conceptual diagram explaining another modification of an optical modulation apparatus. It is a conceptual diagram explaining another modification of a light modulation apparatus. It is a conceptual diagram explaining another modification of a light modulation apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Light source device, 20 ... Illumination optical system, 30 ... Color separation optical system, 40 ... Light modulation part, 40a, 40b, 40c ... Liquid crystal light valve, 41a, 41b, 41c ... Liquid crystal panel, 42a, 42b, 42c ... 1 polarizing plate, 43a, 43b, 43c ... second polarizing plate, 44a, 44b, 44c ... light diffusion member, 50 ... cross dichroic prism, 60 ... projection lens, 200 ... projector, OA ... system optical axis

Claims (8)

An illumination device that uniformizes light from the light source to form illumination light;
A liquid crystal device illuminated by the illumination light from the illumination device; a polarizing plate disposed in a preceding stage of the liquid crystal device for adjusting a polarization direction of the illumination light incident on the liquid crystal device; and the liquid crystal device from the polarizing plate A light diffusing member disposed between the incident surface and the light diffusing member for diffusing the illumination light; and
A projection optical system that projects image light that has passed through the light modulation device;
A projector comprising:   The projector according to claim 1, wherein the light diffusing member is spaced apart from the liquid crystal device.   The projector according to claim 1, wherein the light diffusing member is attached to an exit surface side of the polarizing plate.   4. The projector according to claim 1, wherein the light diffusing member is configured by a multi-lens array in which a plurality of small lenses are arranged in a planar shape.   The projector according to claim 4, wherein the multi-lens array is obtained by randomly arranging the plurality of small lenses.   The projector according to claim 4, wherein the liquid crystal device includes a plurality of liquid crystal cells arranged in a plane with a predetermined pattern, and the plurality of small lenses are arranged in a pattern different from the predetermined pattern.   4. The projector according to claim 1, wherein the light diffusing member is configured by forming random irregularities on a surface existing from the polarizing plate to an incident surface of the liquid crystal device. 5. .   The projector according to any one of claims 1 to 3, wherein the light diffusion member is a sheet having a portion that diffuses light inside or on a surface.

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