Projection optical device and projector

Abstract

To provide a projection optical device and projector that can suppress a shift of pixels of a projected image caused by heat.SOLUTION: A projection optical device comprises an optical system that image light enters; a reflector element that reflects the image light emitted from the optical system, and a housing that houses the optical system and at least part of the reflector element. The reflector element includes a base material having a first surface on which the image light is incident and a second surface opposite from the first surface, a reflection layer provided at the first surface of the base material, and a heat dissipation member provided at the second surface of the base material and including a protrusion protruding from the second surface.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a projection optical device and a projector. [Background technology]

[0002] In recent years, there has been a demand for short-focus projectors that are compact yet capable of displaying large-screen projection images. One such short-focus projector uses a projection optical device that combines a lens and a concave mirror, and projects an enlarged image reflected by the mirror onto a screen (see, for example, Patent Document 1 below). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-085922 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned short-focus projector, the image light is incident on the mirror of the projection optical device in a condensed state. Therefore, the mirror may be deformed by heat generated by a locally high illuminance of the image light. The image light reflected by the deformed mirror is projected at a position shifted from the specified position on the screen. This causes a problem that the image quality of the projected image is degraded due to partial movement of the projected image light. [Means for solving the problem]

[0005] In order to solve the above problems, according to one aspect of the present invention, there is provided a projection optical device comprising: an optical system into which image light is incident; a reflective element that reflects the image light emitted from the optical system; and a housing that accommodates the optical system and at least a part of the reflective element, wherein the reflective element has a substrate having a first surface into which the image light is incident and a second surface opposite to the first surface; a reflective layer provided on the first surface of the substrate; and a heat dissipation member provided on the second surface of the substrate and including a protrusion protruding from the second surface.

[0006] According to one aspect of the present invention, there is provided a projector comprising a light source device that emits light, a light modulation device that modulates the light from the light source device, and a projection optical device of the above aspect that projects image light modulated by the light modulation device. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a projector according to a first embodiment. [Diagram 2] FIG. 1 is a cross-sectional view showing a schematic configuration of a projection optical device provided in a projector. [Diagram 3] FIG. 4 is a diagram showing an illuminance distribution formed on a reflecting mirror. [Figure 4] FIG. 11 is a cross-sectional view showing a schematic configuration of a projection optical device according to a second embodiment. [Diagram 5] FIG. 11 is a cross-sectional view showing a schematic configuration of a projection optical device according to a third embodiment. [Figure 6] FIG. 13 is a cross-sectional view showing a schematic configuration of a projection optical device according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that the drawings used in the following description may show characteristic parts in an enlarged scale for the sake of convenience in order to make the characteristics easier to understand, and the dimensional ratios of each component may not necessarily be the same as in reality.

[0009] An example of a projector according to this embodiment will be described. The projector of this embodiment is a projection type image display device that displays a full-color image on a screen (projection surface). The projector is equipped with three light modulation devices made of liquid crystal light valves that modulate the red, green, and blue light.

[0010] FIG. 1 is a diagram showing a schematic configuration of a projector according to this embodiment. 1, the projector 1 of this embodiment includes a main body 20, an exterior housing 2a, and a projection optical device 6. The main body 20 is housed in the exterior housing 2a. The exterior housing 2a is made of, for example, a resin material, and has a configuration in which a plurality of members are combined.

[0011] The projection optical device 6 is disposed with a portion thereof protruding from the exterior housing 2a. The projection optical device 6 of this embodiment is a projection lens unit compatible with ultra-short focal lengths. With the projection optical device 6 attached, the projector 1 can be installed in a position close to a screen and project an image. However, the projection optical device 6 does not necessarily have to be configured to be detachable from the main body 20. A detailed configuration of the projection optical device 6 will be described later.

[0012] The main body 20 includes a light source device 2 as an illumination optical system, a color separation optical system 3, a light modulation device 11R, a light modulation device 11G, a light modulation device 11B, and a synthesis optical system 5.

[0013] The light source device 2 includes a light source 21, a first lens array 22, a second lens array 23, a polarization conversion element 24, and a superimposing lens 25. The first lens array 22 and the second lens array 23 each have a configuration in which a plurality of microlenses are arranged in a matrix in a plane perpendicular to the optical axis.

[0014] In the projector 1 of the present embodiment, a lamp that is a discharge type light source is used as the light source 21, but the type of the light source 21 is not limited to a discharge type light source. As the light source 21, for example, a solid-state light source such as a light-emitting diode or a laser may be used, or a light source device including a wavelength conversion element that includes a phosphor that generates fluorescent light when irradiated with excitation light may be used.

[0015] Light emitted from the light source 21 is divided into a plurality of partial light beams by the first lens array 22. The plurality of partial light beams are superimposed in the effective display areas of the three light modulation devices 11R, 11G, and 11B, which are the illumination targets, by the second lens array 23 and the superimposing lens 25. That is, the first lens array 22, the second lens array 23, and the superimposing lens 25 constitute an integrator optical system that illuminates the light modulation device 11R, the light modulation device 11G, and the light modulation device 11B with a substantially uniform illuminance distribution by the light emitted from the light source 21.

[0016] The polarization conversion element 24 converts the unpolarized light emitted from the light source 21 into linearly polarized light that can be used by the three optical modulation devices 11R, 11G, and 11B.

[0017] The color separation optical system 3 separates the illumination light WL from the light source device 2 into red light LR, green light LG, and blue light LB. The color separation optical system 3 generally includes a first dichroic mirror 7a, a second dichroic mirror 7b, a first total reflection mirror 8a, a second total reflection mirror 8b, a third total reflection mirror 8c, and a first relay lens 9a and a second relay lens 9b.

[0018] The first dichroic mirror 7a separates the illumination light WL from the light source device 2 into red light LR, green light LG, and blue light LB. The first dichroic mirror 7a transmits the separated red light LR and reflects the green light LG and blue light LB. On the other hand, the second dichroic mirror 7b reflects the green light LG and transmits the blue light LB, thereby separating the other light into the green light LG and blue light LB.

[0019] The first total reflection mirror 8a is disposed in the optical path of the red light LR and reflects the red light LR transmitted through the first dichroic mirror 7a toward the optical modulation device 11R. On the other hand, the second total reflection mirror 8b and the third total reflection mirror 8c are disposed in the optical path of the blue light LB and guide the blue light LB transmitted through the second dichroic mirror 7b to the optical modulation device 11B. The green light LG is reflected from the second dichroic mirror 7b toward the optical modulation device 11G.

[0020] The first relay lens 9a and the second relay lens 9b are disposed after the second dichroic mirror 7b in the optical path of the blue light LB.

[0021] The light modulation device 11R modulates the red light LR according to image information to form image light corresponding to the red light LR. The light modulation device 11G modulates the green light LG according to image information to form image light corresponding to the green light LG. The light modulation device 11B modulates the blue light LB according to image information to form image light corresponding to the blue light LB.

[0022] The light modulation device 11R, the light modulation device 11G, and the light modulation device 11B are, for example, a transmissive liquid crystal panel. Pixels are arranged on the liquid crystal panel, and each pixel is modulated according to image information. In addition, a polarizing plate (not shown) is arranged on each of the entrance side and the exit side of the liquid crystal panel.

[0023] Field lenses 10R, 10G, and 10B are disposed on the incident sides of optical modulation device 11R, optical modulation device 11G, and optical modulation device 11B, respectively. Field lenses 10R, 10G, and 10B collimate the red light LR, green light LG, and blue light LB incident on optical modulation device 11R, optical modulation device 11G, and optical modulation device 11B, respectively.

[0024] The image light from the light modulation device 11R, the light modulation device 11G, and the light modulation device 11B is incident on the combining optical system 5. The combining optical system 5 combines the image light corresponding to the red light LR, the green light LG, and the blue light LB, respectively, and emits the combined image light toward the projection optical device 6. For example, a cross dichroic prism is used for the combining optical system 5. The combined light generated by the combining optical system 5 is emitted toward the projection optical device 6.

[0025] The combined light emitted from the main body 20 is projected as image light IL via the projection optical device 6 onto a projection surface such as a screen (not shown).

[0026] The projection optical device 6 will now be described. The projection optical device 6 of this embodiment projects a display image on a reduction-side conjugate plane onto an enlargement-side conjugate plane to generate a projection image. In this embodiment, the reduction-side conjugate plane corresponds to the display surfaces of the liquid crystal panels of the light modulation device 11R, the light modulation device 11G, and the light modulation device 11B, and the enlargement-side conjugate plane corresponds to the screen, which is the projection surface. The projection optical device 6 of this embodiment forms an intermediate image of the display image at a position conjugate with each display surface of the light modulation device 11R, the light modulation device 11G, and the light modulation device 11B, which are the reduction side conjugate planes, and enlarges and projects the intermediate image onto the screen, which is the enlargement side conjugate plane.

[0027] In the following drawings, an XYZ Cartesian coordinate system will be used as necessary for explanation. The Z axis is an axis along the up-down direction of the projection image projected by the projection optical device 6 onto the screen. The X axis is an axis parallel to the optical axis AX1 of the projection optical device 6. The Y axis is an axis perpendicular to the X axis and the Z axis, and is an axis along the left-right direction of the projection image projected by the projection optical device 6 onto the screen.

[0028] Fig. 2 is a cross-sectional view showing a schematic configuration of the projection optical device 6 of this embodiment. Fig. 2 is a cross-sectional view of the projection optical device along a plane parallel to the XZ plane. As shown in FIG. 2, the projection optical device 6 has a lens group (optical system) 61, a first reflecting mirror (reflecting element) 62, and a first lens unit housing (housing) 63 that houses the lens group 61 and the first reflecting mirror 62. The lens group 61 is composed of a plurality of lenses, and emits the image light IL from the main body 20 toward the first reflecting mirror 62. In the lens group 61, a plurality of lenses are arranged on an optical axis AX1. The lenses constituting the lens group 61 include lenses of various shapes such as convex lenses and concave lenses. The number, shape, size, and arrangement of the lenses constituting the lens group 61 are not particularly limited.

[0029] The first reflecting mirror 62 reflects the image light IL emitted from the lens group 61 to bend the optical path. The first reflecting mirror 62 projects the reflected image light IL onto a projection surface that is a magnification side conjugate surface. The reflecting surface 62a of the first reflecting mirror 62 is composed of an aspheric mirror that reflects the image light IL to widen the angle. The first reflecting mirror 62 is disposed so that the reflecting surface 62a faces the opposite side (-X side) and the upper side (+Z side) to the light emission direction from the lens group 61. In this embodiment, the first reflecting mirror 62 reflects the main ray of the image light IL along the optical axis AX1 of the lens group 61 obliquely backward at an acute angle with respect to the optical axis AX1. The image light IL reflected by the first reflecting mirror 62 is emitted toward the screen from a light emission part 633 of the first lens unit housing 63 described later.

[0030] Based on this configuration, the projection optical device 6 of this embodiment is capable of enlarging and projecting the image light IL onto a screen that is placed at a short distance from the projector 1.

[0031] The first lens unit housing 63 has a lens barrel portion 630, a mirror holding portion 631, a light entrance portion 632, a light exit portion 633, and a first cover member 634. Note that the constituent material, shape, dimensions, etc. of the first lens unit housing 63 are not particularly limited.

[0032] The lens barrel portion 630 is a portion that houses the lens group 61, and the mirror holding portion 631 is a portion for holding the first reflecting mirror 62. Although not shown, the lens barrel portion 630 includes a support portion for supporting each lens that constitutes the lens group 61. In this embodiment, the mirror holding portion 631 includes a support portion 631a for supporting the first reflecting mirror 62. The first reflecting mirror 62 is attached to the support portion 631a of the mirror holding portion 631 by a screw member 64.

[0033] The light entrance portion 632 takes in the image light IL emitted from the main body portion 20 into the projection optical device 6. The light exit portion 633 emits the image light IL reflected by the first reflecting mirror 62 to the outside of the projection optical device 6. The light entrance portion 632 and the light exit portion 633 are formed of, for example, a window member having translucency. In the case of this embodiment, for example, the light entrance portion 632 has a lens shape, so that the image light IL can be efficiently taken in.

[0034] A first opening 63a is provided in the first lens unit housing 63. In this embodiment, the first opening 63a is provided in a mirror holding portion 631 of the first lens unit housing 63. The first opening 63a connects the internal space of the first lens unit housing 63 with the outside. The lens group 61 and the first reflecting mirror 62 are detachably attached to the inside of the first lens unit housing 63 through the first opening 63a. The first cover member 634 is detachably attached to the first lens unit housing 63 so as to cover the first opening 63a.

[0035] The first cover member 634 seals the internal space of the first lens unit housing 63 in an airtight state. That is, the first lens unit housing 63 of this embodiment has a sealed structure that seals the storage space S that houses the lens group 61 and the first reflecting mirror 62. Therefore, the first lens unit housing 63 suppresses the intrusion of dust into the internal storage space S, and can suppress a deterioration in the optical characteristics of the lens group 61 and the first reflecting mirror 62 due to the adhesion of dust, and a deformation or damage of the lens group 61 and the first reflecting mirror 62 due to heat generation by dust.

[0036] Generally, short-focus projectors are configured to project image light onto a screen by reflecting it off a reflective mirror, thereby enlarging the image light and projecting it. This causes an unevenness in the light density of the image light on the reflective mirror, and the illuminance distribution formed on the reflective mirror ends up including areas of locally high illuminance.

[0037] In the projection optical device 6 of this embodiment as well, the illuminance distribution formed on the first reflecting mirror 62 by the image light IL emitted from the main body 20 includes areas where the illuminance is locally high. Fig. 3 is a diagram showing the illuminance distribution formed on the first reflecting mirror 62 of this embodiment. Specifically, Fig. 3 is a diagram showing the illuminance distribution of the image light IL formed on the reflecting layer 621, and is shown by the maximum value (black) of the illuminance of the image light IL and the minimum value (white) of the image light IL.

[0038] 3, in the first reflecting mirror 62 of the present embodiment, the illuminance of the image light IL is locally high on the lower side (the -Z side shown in FIG. 2) of the reflecting surface 62a. The illuminance distribution SP of the image light IL includes a first region SP1 in which the illuminance is higher than a predetermined value. In other words, the first region SP1 means a region of the reflecting surface 62a in which the illuminance of the image light IL is locally high. The predetermined value defining the first region SP1 is preferably an illuminance of 50% or more, more preferably an illuminance of 60% or more, and most preferably an illuminance of 70% or more.

[0039] In the projection optical device 6 of this embodiment, the heat dissipation properties of the first reflecting mirror 62 are improved to reduce the temperature of the first reflecting mirror 62, and local deformation of the first reflecting mirror 62 is suppressed to suppress partial pixel movement of the projected image caused by heat.

[0040] The main configuration of the projection optical device 6 of this embodiment will be described below. In the projection optical device 6 of this embodiment, the first reflection mirror 62 has a base material 620, a reflection layer 621, and a first heat dissipation member 622. The base material 620 has an inner surface (first surface) 620a to which image light is incident, and an outer surface (second surface) 620b opposite to the inner surface 620a. The inner surface 620a of the base material 620 has a concave shape. Specifically, the inner surface 620a has, for example, any of a spherical shape, an aspherical shape, and a free-form shape.

[0041] In this embodiment, the base material 620 is made of a plastic material. Since plastic has a higher workability than glass, the inner surface 620a can be easily formed into a desired shape with high precision. On the other hand, plastic is easily deformed by heat, and if the temperature of the reflective layer 621 becomes too high, the base material 620 may be deformed.

[0042] As described below, the first reflection mirror 62 of the present embodiment can suppress deformation of the base material 620 due to heat by improving the heat dissipation of the reflection layer 621 with the first heat dissipation member 622. Thus, the first reflection mirror 62 has excellent processability and is suppressed from deformation due to heat.

[0043] The reflective layer 621 is formed along the inner surface 620a. Therefore, the surface 621a of the reflective layer 621 has a concave shape following the inner surface 620a. In this embodiment, the surface 621a of the reflective layer 621 corresponds to the reflective surface 62a of the first reflective mirror 62.

[0044] The reflective layer 621 of this embodiment is composed of a metal film or a dielectric film. Examples of materials used for the metal film constituting the reflective layer 621 include aluminum and silver. Examples of materials used for the dielectric film constituting the reflective layer 621 include a film that reflects visible light of 400 nm to 700 nm. In this embodiment, the reflective layer 621 is formed by using a vapor deposition method. That is, the reflective layer 621 is formed integrally with the inner surface 620a of the base material 620. The thickness of the reflective layer 621 is set to, for example, 1 μm or less, and the surface 621a of the reflective layer 621 is a semi-mirror or mirror surface. Specifically, the inner surface 620a of the base material 620 is formed so that the surface roughness (Rz) of the surface 621a of the reflective layer 621 is 0.2 μm or less.

[0045] The first heat dissipation member 622 abuts against the outer surface 620 b of the base material 620 . Here, the term "contact" may mean that the first heat dissipation member 622 and the outer surface of the base material 620 are in direct contact with each other, or that a thermally conductive member 626 such as thermal grease is included between the first heat dissipation member 622 and the base material 620. Note that instead of the thermally conductive member 626, an adhesive containing thermally conductive particles may be used.

[0046] The first heat dissipation member 622 is provided on at least a portion of the outer surface 620b of the base material 620. In this embodiment, the first heat dissipation member 622 is provided in at least the second region SP2 of the outer surface 620b as shown in FIG 2. The second region SP2 is a region corresponding to the first region SP1 of the reflective layer 621.

[0047] Specifically, the second region SP2 corresponding to the first region SP1 is a region on the outer surface 620b that overlaps with the outline of the first region SP1 in the minimum thickness direction of the reflective layer 621 and the base material 620. The minimum thickness direction of the reflective layer 621 corresponds to the direction along the surface normal to the surface 621a of the reflective layer 621, and the minimum thickness direction of the base material 620 corresponds to the direction along the surface normal to the surfaces of the base material 620 (the inner surface 620a and the outer surface 620b).

[0048] Here, the first region SP1 of the reflective layer 621 has a locally high illuminance, and therefore has the highest temperature on the surface 621a of the reflective layer 621. That is, the second region SP2 of the outer surface 620b of the base material 620, which corresponds to the first region SP1, has the highest temperature because heat from the first region SP1 is easily transferred thereto.

[0049] In the case of the present embodiment, since the first heat dissipation member 622 is provided at least in the second region SP2 of the outer surface 620b as described above, the heat of the first region SP1, which is the hottest on the surface 621a of the reflective layer 621, can be dissipated to the first heat dissipation member 622. Therefore, the temperature of the first region SP1 can be efficiently reduced, and therefore the temperature of the first reflecting mirror 62 can be efficiently reduced.

[0050] The first heat dissipation member 622 is preferably provided over 80% or more of the entire area of ​​the outer surface 620b including the second region SP2, and more preferably over the entire outer surface 620b. In this way, the heat dissipation property of the first reflection mirror 62 can be further improved.

[0051] In the projection optical device 6 of this embodiment, the first lens unit housing 63 has a sealed structure, which tends to trap heat inside. In contrast, the first reflecting mirror 62 has improved heat dissipation properties due to the first heat dissipation member 622, so it is less susceptible to the effects of heat trapped inside the housing. Therefore, the projection optical device 6 of this embodiment can achieve both improved dustproofness inside the first lens unit housing 63 and cooling of the first reflecting mirror 62.

[0052] The first heat dissipation member 622 of this embodiment has a sheet metal member 623 provided along the outer surface 620b of the base material 620, and a heat pipe 624 connected to the sheet metal member 623 and protruding from the outer surface 620b. That is, the first heat dissipation member 622 of this embodiment includes the heat pipe 624 as a protruding part protruding from the outer surface 620b. The heat pipe 624 is fixed to the sheet metal member 623 via a screw member or an adhesive. The heat pipe 624 extends diagonally downward (to the +X side and the -Z side) on the back side of the outer surface 620b of the base material 620. The sheet metal member 623 is fixed to the mirror holding part 631 together with the base material 620 via the screw member 64. As a result, the first heat dissipation member 622 and the outer surface 620b of the base material 620 are abutted against each other. In this manner, the first reflection mirror 62 is fixed to the support part 631a of the mirror holding part 631 via the screw member 64.

[0053] The heat pipe 624 is composed of a pipe containing a refrigerant. The heat pipe 624 has a heat receiving section 65 provided on one end side and a heat dissipation section 66 provided on the other end side. The heat pipe 624 has the heat receiving section 65 connected to the sheet metal member 623 and the heat dissipation section 66 exposed to the outside of the first lens unit housing 63. The heat pipe 624 can cool the sheet metal member 623 by dissipating the heat of the refrigerant that has been evaporated and turned into gas by the heat received by the heat receiving section 65 at the heat dissipation section 66, thereby condensing and liquefying the refrigerant. Note that the material of the heat pipe 624 is a pipe made of a metal such as silver, copper, gold, or aluminum that has excellent thermal conductivity.

[0054] A portion of the heat pipe 624 is exposed to the outside of the first lens unit housing 63. In the case of this embodiment, a heat dissipation section 66 of the heat pipe 624 is exposed to the outside of the first lens unit housing 63. More specifically, the heat dissipation section 66 of the heat pipe 624 is exposed to the outside of the first lens unit housing 63 via a first slit 634a provided in the first cover member 634. The gap between the heat dissipation section 66 and the first slit 634a is sealed with a sealing member 68. This keeps the inside of the first lens unit housing 63 sealed.

[0055] Moreover, the heat pipe 624 is provided with heat dissipation fins 67 on a heat dissipation section 66 which is a portion exposed to the outside of the first lens unit housing 63. Thus, the heat pipe 624 improves the heat dissipation performance of the heat dissipation section 66 by the heat dissipation fins 67. As with the heat pipe 624, the material of the heat dissipation fins 67 is a metal having excellent thermal conductivity, such as silver, copper, gold, or aluminum.

[0056] Next, the assembly process of the projection optical device 6 of this embodiment will be described. First, the first heat dissipation member 622 is brought into contact with the outer surface 620b of the base material 620 on which the reflective layer 621 is formed, via the thermally conductive member 626, by the screw members 64, to assemble the second reflecting mirror 162. Next, the first cover member 634 is attached to the first lens unit housing 63 so as to cover the first opening 63a. At this time, the heat dissipation portion 66 of the heat pipe 624 is exposed to the outside from the first lens unit housing 63 through the first slit 634a of the first cover member 634. Next, heat dissipation fins 67 are attached to the heat dissipation portion 66 of the heat pipe 624 exposed from the first lens unit housing 63 . Finally, the gap between the first slit 634a of the first cover member 634 and the heat pipe 624 is sealed with a sealing member 68. In this manner, the assembly of the projection optical device 6 is completed.

[0057] As described below, the projection optical device 6 of this embodiment includes a lens group 61 on which image light IL is incident, a first reflecting mirror 62 that reflects the image light IL emitted from the lens group 61, and a first lens unit housing 63 that houses the lens group 61 and at least a part of the first reflecting mirror 62. The first reflecting mirror 62 has a base material 620 having an inner surface 620a on which the image light IL is incident and an outer surface 620b opposite the inner surface 620a, a reflective layer 621 provided on the inner surface 620a of the base material 620, and a second heat dissipation member 625 provided on the outer surface 620b of the base material 620 and including a heat pipe 624 protruding from the outer surface 620b.

[0058] According to the projection optical device 6 of this embodiment, the first reflecting mirror 62 that reflects the image light IL has the first heat dissipation member 622 on the opposite side of the reflective layer 621, and therefore the heat absorbed by the first heat dissipation member 622 from the reflective layer 621 can be dissipated through the heat pipe 624, thereby lowering the temperature of the first reflecting mirror 62. In addition, even if image light IL having an uneven illuminance distribution including locally strong illuminance is incident on the reflective layer 621, the temperature of the reflective layer 621 can be effectively lowered, thereby suppressing the occurrence of local temperature unevenness in the reflective layer 621. Therefore, according to the projection optical device 6 of this embodiment, the reflective layer 621 of the first reflecting mirror 62 is unlikely to become locally hot, which suppresses deformation of the high-temperature portion of the first reflecting mirror 62. Therefore, it is possible to project a high-quality image in which partial pixel movement of the projected image caused by the heat of the first reflecting mirror 62 is suppressed.

[0059] The projector 1 of this embodiment includes a light source device 2 that emits illumination light, light modulation devices 11R, 11G, and 11B that modulate the illumination light from the light source device 2, and a projection optical device 6 that projects the light modulated by the light modulation devices 11R, 11G, and 11B.

[0060] According to the projector 1 of this embodiment, by being equipped with a projection optical device 6 that suppresses partial pixel movement of the projected image caused by the heat of the first reflecting mirror 62, it is possible to provide a single-focus projector that projects high-quality images onto a screen from a close distance.

[0061] Furthermore, the projector 1 of the present embodiment is ideal for use as an interactive projector having an interactive function that reflects position information detected on a screen in a projected image, for example.

[0062] In general, an interactive projector projects a grid pattern made of infrared rays onto a screen from an optical system different from the projection optical device, and acquires position information on the projected image pointed to by the user's fingertip, pen tip, etc. based on the grid pattern. In an interactive projector, it is assumed that the coordinates of the projected image and the coordinates of the grid pattern match. Therefore, if the pixels of the projected image move, the coordinates of the projected image and the coordinates of the grid pattern do not match, and the interactive function cannot be fully exhibited. In contrast, according to the projector 1 of this embodiment, pixel movement of the projected image caused by the heat of the first reflection mirror 62 can be suppressed, so that the interactive function can be stably exhibited.

[0063] Second embodiment Next, another configuration of the projection optical device will be described as the second embodiment of the present invention. Since the difference between this embodiment and the first embodiment is the structure of the reflecting mirror, the following mainly describes the peripheral configuration of the reflecting mirror. In this embodiment, the same reference numerals are used for the configurations or members common to the first embodiment, and detailed description will be omitted.

[0064] FIG. 4 is a cross-sectional view showing a schematic configuration of the projection optical device of the present embodiment. As shown in FIG. 4, the projection optical device 106 of this embodiment has a lens group 61, a second reflecting mirror (reflecting element) 162, and a second lens unit housing (housing) 163 that houses the lens group 61 and the second reflecting mirror 162.

[0065] The second lens unit housing 163 of the present embodiment has a lens barrel portion 630, a mirror holding portion 631, a light entrance portion 632, a light exit portion 633, and a second cover member 635. A second opening 163a is provided in the mirror holding portion 631 of the second lens unit housing 163. The second opening 163a communicates the internal space of the second lens unit housing 163 with the outside. The lens group 61 is detachably attached to the inside of the second lens unit housing 163 through the second opening 163a. ​​The second cover member 635 is detachably attached to the first lens unit housing 63 so as to cover a part of the second opening 163a. ​​The second cover member 635 is made of, for example, a plastic material. The second cover member 635 may be made of a single member or may be made of multiple members.

[0066] The second reflection mirror 162 of this embodiment has a base material 620 having a reflection layer 621 formed on an inner surface 620a, and a second heat dissipation member 625. The second heat dissipation member 625 is provided on a part of an outer surface 620b of the base material 620. The second heat dissipation member 625 of this embodiment also serves as a cover member that covers a part of the first opening 63a. The second heat dissipation member 625 covers the first opening 63a together with the second cover member 635. More specifically, the second heat dissipation member 625 covers a part of the first opening 63a that is not covered by the second cover member 635. That is, in this embodiment, the entire second heat dissipation member 625 of the second reflection mirror 162 is exposed to the outside of the second lens unit housing 163.

[0067] The second heat dissipation member 625 and the second cover member 635 seal the internal space of the first lens unit housing 63 in an airtight state, thereby preventing a deterioration in optical characteristics due to dust adhering to the lens group 61 and reflective layer 621 contained inside, and preventing deformation or damage to the lens group 61 and reflective layer 621 due to heat generated by dust.

[0068] The second heat dissipation member 625 of this embodiment is bonded to the outer surface 620b of the base material 620. In this embodiment, a thermally conductive member 626 such as thermal grease is sandwiched between the second heat dissipation member 625 and the outer surface 620b of the base material 620. This makes it possible to improve the thermal conductivity between the second heat dissipation member 625 and the base material 620.

[0069] The second heat dissipation member 625 is a heat sink having a base portion 625a and heat dissipation fins 625b connected to the base portion 625a. The base portion 625a is a metal plate provided along the outer surface 620b. The heat dissipation fins 625b are composed of a plurality of fin-shaped members and correspond to protruding portions protruding from the outer surface 620b. Note that, among the heat dissipation fins 625b, a portion provided on the outer edge of the base portion 625a functions as a fixing portion for fixing the second heat dissipation member 625 to the second cover member 635 as described later.

[0070] In the second reflection mirror 162 of this embodiment, the base material 620 on which the reflective layer 621 is formed is fixed to the support portion 631a of the mirror holding portion 631 via the first screw member 71. The second heat dissipation member 625 is fixed to the second lens unit housing 163 together with the second cover member 635 via the second screw member 72. The base material 620 and the second heat dissipation member 625 are bonded together via a thermally conductive member 626.

[0071] Here, the assembly process of the projection optical device 106 of this embodiment will be described. First, second heat dissipation member 625 is bonded via thermally conductive member 626 to outer surface 620b of base material 620 on which reflective layer 621 is formed, and second reflecting mirror 162 is assembled. Next, the second reflecting mirror 162 is disposed inside the second lens unit housing 163 through the second opening 163a, and then the second reflecting mirror 162 is fixed to the support portion 631a of the mirror holding portion 631 with the first screw member 71. Then, the second cover member 635 is attached to the second lens unit housing 163. As a result, the second opening 163a of the second lens unit housing 163 is covered by the second heat dissipation member 625 of the second reflecting mirror 162 and the second cover member 635. Finally, the second heat dissipation member 625 and the second cover member 635 of the second reflecting mirror 162 are fixed to the second lens unit housing 163 by the second screw members 72 . In this manner, the assembly of the projection optical device 106 is completed.

[0072] According to the projection optical device 106 of the present embodiment, since the second reflection mirror 162 having the second heat dissipation member 625 provided on the opposite side to the reflection layer 621 that reflects the image light IL is provided, the temperature of the second reflection mirror 162 can be reduced by dissipating the heat of the reflection layer 621 by the second heat dissipation member 625. Therefore, according to the projection optical device 106 of the present embodiment, deformation of the second reflection mirror 162 caused by the reflection layer 621 becoming locally hot is suppressed, so that a good quality image can be projected in which partial pixel movement of the projection image caused by the heat of the second reflection mirror 162 is suppressed.

[0073] Third embodiment Next, another configuration of the projection optical device will be described as the third embodiment of the present invention. Since the difference between this embodiment and the first embodiment is the structure of the reflecting mirror, the following mainly describes the peripheral configuration of the reflecting mirror. In this embodiment, the same reference numerals are used for the configurations or members common to the first embodiment, and detailed description will be omitted.

[0074] FIG. 5 is a cross-sectional view showing a schematic configuration of the projection optical device of the present embodiment. As shown in FIG. 5, the projection optical device 206 of this embodiment has a lens group 61, a third reflecting mirror (reflecting element) 262, and a third lens unit housing (housing) 263 that houses the lens group 61 and the third reflecting mirror 262.

[0075] The third lens unit housing 263 of the present embodiment has a lens barrel portion 630, a mirror holding portion 631, a light entrance portion 632, a light exit portion 633, and a third cover member 636. The mirror holding portion 631 of the third lens unit housing 263 is provided with a third opening 263a. The third opening 263a communicates the internal space of the third lens unit housing 263 with the outside. The lens group 61 and the third reflecting mirror 262 are detachably attached to the inside of the third lens unit housing 263 through the third opening 263a. The third cover member 636 is detachably attached to the third lens unit housing 263 so as to cover the third opening 263a. The third cover member 636 is made of, for example, a plastic material. The third cover member 636 may be made of a single member or may be made of multiple members.

[0076] The third reflection mirror 262 of this embodiment has a base material 620 having a reflection layer 621 formed on an inner surface 620a, a third heat dissipation member 627, and a thermally conductive member 626. The third heat dissipation member 627 of the present embodiment includes a sheet metal member 623 provided along an outer surface 620b of the base material 620, and a heat pipe 624 connected to the sheet metal member 623 and protruding from the outer surface 620b.

[0077] The third reflection mirror 262 of this embodiment and the first reflection mirror 62 of the first embodiment differ in the direction in which the heat pipe extends. The heat pipe 624 of the first embodiment extends obliquely downward (+X side and -Z side) from the back side of the outer surface 620b of the base material 620. In contrast, the heat pipe 624 of this embodiment extends obliquely upward (+X side and +Z side) so as to be slightly away from the back side of the outer surface 620b of the base material 620, and then extends upward (+Z side).

[0078] In this embodiment, heat dissipation section 66 of heat pipe 624 is exposed to the outside of first lens unit housing 63 through third slit 636a provided in third cover member 636. Heat pipe 624 is provided with heat dissipation fins 67 on heat dissipation section 66 exposed to the outside of first lens unit housing 63. The gap between heat dissipation section 66 and third slit 636a is sealed with sealing member 68. This keeps the inside of first lens unit housing 63 sealed.

[0079] The third cover member 636 of the present embodiment has a pipe holding portion 636b that holds a part of the heat pipe 624. As a result, the heat pipe 624 is held in the third lens unit housing 263 via the third cover member 636, and the heat pipe 624 can be stably held. This makes it possible to suppress wobbling occurring in the heat pipe 624 and to suppress the occurrence of defects such as separation of the connection portion between the heat pipe 624 and the sheet metal member 623.

[0080] Here, the assembly process of the projection optical device 206 of this embodiment will be described. First, the third heat dissipation member 627 is brought into contact with the outer surface 620b of the base material 620 on which the reflective layer 621 is formed by the screw members 64 via the thermally conductive member 626, and the third reflection mirror 262 is assembled. Next, the third cover member 636 is attached to the second lens unit housing 163 so as to cover the third opening 263a. At this time, the heat dissipation portion 66 of the heat pipe 624 is exposed to the outside from the second lens unit housing 163 through the third slit 636a of the third cover member 636. Next, the heat dissipation fins 67 are attached to the heat dissipation portion 66 of the heat pipe 624 exposed from the second lens unit housing 163 . Finally, the gap between the third slit 636a of the third cover member 636 and the heat pipe 624 is sealed with a sealing member 68. In this manner, the assembly of the projection optical device 206 is completed.

[0081] The projection optical device 206 of this embodiment also includes a third reflecting mirror 262 having a third heat dissipation member 627, which makes it possible to suppress deformation of the third reflecting mirror 262 caused by the reflective layer 621 becoming locally hot, thereby making it possible to project a high-quality image in which partial pixel movement of the projected image caused by heat from the third reflecting mirror 262 is suppressed.

[0082] (Fourth embodiment) Next, another configuration of the projection optical device will be described as the fourth embodiment of the present invention. Since the difference between this embodiment and the first embodiment is the structure of the reflecting mirror, the following mainly describes the peripheral configuration of the reflecting mirror. In this embodiment, the same reference numerals are used for the configurations or members common to the first embodiment, and detailed description will be omitted.

[0083] Fig. 6 is a cross-sectional view showing a schematic configuration of the projection optical device of this embodiment, taken along a plane parallel to the XY plane. As shown in FIG. 6, the projection optical device 306 of this embodiment has a lens group 61, a fourth reflecting mirror (reflecting element) 362, and a fourth lens unit housing (housing) 363 that houses the lens group 61 and the fourth reflecting mirror 362.

[0084] The fourth lens unit housing 363 of the present embodiment has a lens barrel portion 630, a mirror holding portion 631, a light entrance portion 632, a light exit portion 633, and a fourth cover member 637. A fourth opening 363a is provided in the mirror holding portion 631 of the fourth lens unit housing 363. The fourth opening 363a communicates the internal space of the fourth lens unit housing 363 with the outside. The lens group 61 and the fourth reflecting mirror 362 are detachably attached to the inside of the fourth lens unit housing 363 through the fourth opening 363a. The fourth cover member 637 is detachably attached to the fourth lens unit housing 363 so as to cover the fourth opening 363a. The fourth cover member 637 is made of, for example, a plastic material. The fourth cover member 637 may be made of a single member or may be made of multiple members.

[0085] The fourth reflection mirror 362 of this embodiment has a base 620 having a reflection layer 621 formed on an inner surface 620a, a fourth heat dissipation member 628, and a thermally conductive member 626. The fourth heat dissipation member 628 of the present embodiment includes a sheet metal member 623 provided along the outer surface 620b of the base material 620, and a heat pipe 624 connected to the sheet metal member 623 and protruding from the outer surface 620b.

[0086] The fourth reflecting mirror 362 of this embodiment and the fourth reflecting mirror 362 of the third embodiment differ in the direction in which the heat pipe extends. The heat pipe 624 of the third embodiment extends obliquely upward (+X side and +Z side) so as to be slightly away from the back side of the outer surface 620b of the base material 620, and then extends upward (+Z side). In contrast, the heat pipe 624 of this embodiment is provided along the back side of the outer surface 620b of the base material 620, and extends toward both sides in the left-right direction (Y-axis direction).

[0087] The fourth cover member 637 of the present embodiment has pipe holding portions 638 that respectively hold both left and right ends of the heat pipe 624. As a result, the heat pipe 624 is held in the first lens unit housing 63 via the fourth cover member 637, and the heat pipe 624 can be stably held. This makes it possible to suppress wobbling occurring in the heat pipe 624 and to suppress the occurrence of defects such as separation of the connection portion between the heat pipe 624 and the sheet metal member 623.

[0088] In this embodiment, heat dissipation section 66 of heat pipe 624 is exposed to the outside of first lens unit housing 63 through fourth slit 638a provided in pipe holding section 638 of fourth cover member 637. Heat pipe 624 is provided with heat dissipation fins 67 on heat dissipation section 66 exposed to the outside of first lens unit housing 63. The gap between heat dissipation section 66 and fourth slit 638a is sealed with sealing member 68. This keeps the inside of first lens unit housing 63 sealed.

[0089] Here, the assembly process of the projection optical device 306 of this embodiment will be described. First, the fourth heat dissipation member 628 is brought into contact with the outer surface 620b of the base material 620 on which the reflective layer 621 is formed by the screw members 64 via the thermally conductive member 626, and the fourth reflecting mirror 362 is assembled. Next, the fourth cover member 637 is attached to the second lens unit housing 163 so as to cover the fourth opening 363a. At this time, the heat dissipation portion 66 of the heat pipe 624 is exposed to the outside from the second lens unit housing 163 through the fourth slit 638a of the pipe holding portion 638 of the fourth cover member 637. Next, the heat dissipation fins 67 are attached to the heat dissipation portion 66 of the heat pipe 624 exposed from the second lens unit housing 163 . Finally, the gap between the fourth slit 638a of the pipe holding portion 638 and the heat pipe 624 is sealed with a sealing member 68. In this manner, the assembly of the projection optical device 306 is completed.

[0090] The projection optical device 306 of this embodiment also includes a fourth reflecting mirror 362 having a fourth heat dissipation member 628, which can suppress deformation of the fourth reflecting mirror 362 caused by the reflective layer 621 becoming locally hot. This makes it possible to project a high-quality image in which partial pixel movement of the projected image caused by heat from the fourth reflecting mirror 362 is suppressed.

[0091] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. Furthermore, the specific configurations of the various components constituting the light source device, such as the number, arrangement, shape, and materials, are not limited to those in the above embodiment and can be modified as appropriate.

[0092] For example, in the above embodiment, a mirror having a concave reflective surface 62a was used as the first reflective mirror 62, but the present invention is also applicable to a projection optical device using a reflective mirror having a convex or planar reflective surface.

[0093] In the above embodiment, the protrusion that is a part of the heat dissipation member protrudes to the outside of the lens unit housing, but the entire heat dissipation member may be housed inside the lens unit housing. In the projection optical device having this configuration, the heat dissipation of the reflection mirror is improved by providing the heat dissipation member, so that a high-quality image can be projected in which partial pixel movement of the projection image caused by the heat of the reflection mirror is suppressed.

[0094] In the above embodiment, the projection optical device 6 used in the projector 1 that projects visible light onto the screen as image light has been taken as an example. Therefore, the light projected by the projection optical device 6 is visible light, but a film that reflects near-infrared light or infrared light may be used as the dielectric film that constitutes the reflective layer 621 depending on the type and application of the light source of the projector.

[0095] Moreover, the light modulation device 11R, the light modulation device 11G, and the light modulation device 11B are not limited to a transmissive liquid crystal panel. A reflective light modulation device such as a reflective liquid crystal panel may be adopted as the light modulation device 11R, the light modulation device 11G, and the light modulation device 11B. A digital micromirror device that modulates the light emitted from the light source 21 by controlling the emission direction of the incident light for each micromirror as a pixel may be adopted. Furthermore, the present invention is not limited to a configuration in which a light modulation device is provided for each of a plurality of color lights, and a configuration in which a single light modulation device modulates a plurality of color lights in a time-division manner may be adopted.

[0096] In the above embodiment, the light source device according to the present invention is applied to a projector, but the present invention is not limited to this. The light source device according to the present invention can also be applied to lighting fixtures such as automobile headlights.

[0097] The following is a summary of this disclosure. (Appendix 1) an optical system into which image light is incident; A reflecting element that reflects the light emitted from the optical system; a housing that accommodates the optical system and at least a portion of the reflecting element; The reflective element is A substrate having a first surface onto which the image light is incident and a second surface opposite to the first surface; a reflective layer provided on the first surface of the substrate; a heat dissipation member provided on the second surface of the base material and including a protruding portion protruding from the second surface, A projection optical device comprising:

[0098] With a projection optical device having this configuration, the reflective element that reflects light has a heat dissipation member on the opposite side of the reflective layer, so that the heat dissipation member can absorb heat from the reflective layer and dissipate it from the protrusion, thereby lowering the temperature of the reflective element. Furthermore, even if light with an uneven illuminance distribution, including locally strong illuminance, is incident on the reflective layer, the temperature of the reflective layer can be effectively reduced, thereby preventing local temperature unevenness from occurring in the reflective layer. Therefore, according to the projection optical device having this configuration, the reflective layer of the reflective element is unlikely to become locally hot, and deformation of the high-temperature portion of the reflective element is suppressed, so that a high-quality image can be projected by suppressing partial movement of the projected image light caused by the heat of the reflective element.

[0099] (Appendix 2) an illuminance distribution formed by the light on the reflective layer includes a first region in which the illuminance is higher than a predetermined value; The heat dissipation member is provided at least in a second region of the second surface corresponding to the first region. 2. The projection optical device according to claim 1,

[0100] According to this configuration, since the thermally conductive layer is provided at least in the second region of the second surface as described above, heat can be efficiently dissipated from the first region, which is the hottest region on the surface of the reflective layer, to the thermally conductive layer side. Therefore, the temperature of the first region, which is the hottest region, is efficiently reduced, and the temperature of the reflective element can be efficiently reduced.

[0101] (Appendix 3) the heat dissipation member is a heat sink including a heat dissipation fin as the protrusion, At least a portion of the heat dissipation fin is exposed to the outside of the housing. 3. The projection optical device according to claim 1 or 2,

[0102] According to this configuration, the heat sink can efficiently dissipate the heat absorbed from the reflective layer from the portion exposed to the outside of the housing. This improves the cooling performance of the reflective element. In addition, since the heat sink does not dissipate heat inside the housing, the temperature rise inside the housing can be suppressed.

[0103] (Appendix 4) the heat dissipation member includes a heat pipe as the protruding portion, At least a portion of the heat pipe is exposed to the outside of the housing. 3. The projection optical device according to claim 1 or 2,

[0104] According to this configuration, the heat pipe can efficiently release the heat absorbed from the reflective layer from the portion exposed to the outside of the housing. This improves the cooling performance of the reflective element. In addition, since the heat pipe does not release heat inside the housing, the temperature rise inside the housing can be suppressed.

[0105] (Appendix 5) The heat pipe is provided with a heat dissipation fin on a portion exposed to the outside of the housing. 5. The projection optical device according to claim 4,

[0106] According to this configuration, the heat dissipation performance of the heat pipe is improved by the heat dissipation fins, so that the cooling performance of the reflective element can be further improved.

[0107] (Appendix 6) the housing has a sealed structure that seals an accommodation space that accommodates the optical system and the reflecting element; 6. The projection optical device according to claim 1,

[0108] With this configuration, by preventing dust from entering the storage space inside the housing, it is possible to prevent the deterioration of optical properties of the optical system and reflective element due to dust adhesion, and deformation or damage to the optical system and reflective element due to heat generation or ignition by dust.

[0109] (Appendix 7) The substrate is made of a plastic material. 7. The projection optical device according to claim 1,

[0110] According to this configuration, the processability of the reflective element can be improved, and the reflective element can be easily processed into a desired shape.

[0111] (Appendix 8) The reflective layer has a concave shape. 8. The projection optical device according to claim 1,

[0112] According to this configuration, a single focus type projection optical device can be provided by providing a reflective element having a concave reflective layer.

[0113] (Appendix 9) The heat dissipation member also serves as a cover member that covers an opening provided in the housing. 9. The projection optical device according to claim 1,

[0114] According to this configuration, since the heat dissipation member also serves as a cover member for covering the opening of the housing, it is possible to reduce the number of parts constituting the projection optical device, thereby reducing the cost of the projection optical device.

[0115] (Appendix 10) The image light emitted from the reduction-side conjugate surface is incident on the optical system, The reflecting element projects the reflected image light onto a magnification side conjugate plane. 10. The projection optical device according to claim 1,

[0116] According to this configuration, it is possible to provide a single focus type projection optical device that projects a display image on the reduction-side conjugate plane onto the enlargement-side conjugate plane to generate projected image light.

[0117] (Appendix 11) A light source device that emits light; a light modulation device that modulates light from the light source device; and a projection optical device according to any one of Supplementary Note 1 to Supplementary Note 10, which projects image light modulated by the light modulation device. A projector characterized by:

[0118] A projector of this configuration is equipped with a projection optical device that suppresses partial movement of the projected image light caused by heat from the reflective element, making it possible to provide a single-focus projector that projects high-quality images onto a screen from a close distance. In addition, since a projector of this configuration can suppress partial movement of the image light projected onto the screen, it is ideal for use as a projector with an interactive function that reflects position information detected on the screen in the projected image. [Explanation of symbols]

[0119] 1...projector, 2...light source device, 6,106,206,306...projection optical device, 11B,11G,11R...light modulation device, 21...light source, 61...lens group (optical system), 62...first reflecting mirror (reflecting element), 63...first lens unit housing (housing), 66...heat dissipation section, 67,625b...heat dissipation fins, 162...second reflecting mirror (reflecting element), 163...second lens unit housing (housing), 262...third reflecting mirror (reflecting element), 263...third lens unit housing (housing), 362...fourth reflecting mirror (reflecting element), 363...fourth lens unit housing (housing), 620...base material, 621...reflective layer, 624...heat pipe, S...housing space, SP...illuminance distribution, SP1...first region, SP2...second region.

Claims

1. an optical system into which image light is incident; a reflecting element that reflects the image light emitted from the optical system; a housing that accommodates the optical system and at least a portion of the reflecting element; The reflective element is A substrate having a first surface onto which the image light is incident and a second surface opposite to the first surface; a reflective layer provided on the first surface of the substrate; a heat dissipation member provided on the second surface of the base material and including a protruding portion protruding from the second surface, A projection optical device comprising:

2. an illuminance distribution formed on the reflective layer by the image light includes a first region in which the illuminance is higher than a predetermined value; The heat dissipation member is provided at least in a second region of the second surface corresponding to the first region.

2. The projection optical device according to claim 1.

3. the heat dissipation member is a heat sink having heat dissipation fins as the protrusions, At least a portion of the heat dissipation fin is exposed to the outside of the housing.

2. The projection optical device according to claim 1.

4. the heat dissipation member includes a heat pipe as the protruding portion, At least a portion of the heat pipe is exposed to the outside of the housing.

4. The projection optical device according to claim 1, wherein the projection optical device is a projection optical device having a projection lens.

5. The heat pipe is provided with a heat dissipation fin on a portion exposed to the outside of the housing.

5. The projection optical device according to claim 4.

6. the housing has a sealed structure that seals an accommodation space that accommodates the optical system and the reflecting element; 4. The projection optical device according to claim 1, wherein the projection optical device is a projection optical device having a projection lens.

7. The substrate is made of a plastic material.

4. The projection optical device according to claim 1, wherein the projection optical device is a projection optical device having a projection lens.

8. The reflective layer has a concave shape.

4. The projection optical device according to claim 1, wherein the projection optical device is a projection optical device having a projection lens.

9. The heat dissipation member also serves as a cover member that covers at least a portion of an opening provided in the housing.

4. The projection optical device according to claim 1, wherein the projection optical device is a projection optical device having a projection lens.

10. The image light emitted from the reduction-side conjugate surface is incident on the optical system, The reflecting element projects the reflected image light onto a magnification side conjugate plane.

4. The projection optical device according to claim 1, wherein the projection optical device is a projection optical device having a projection lens.

11. A light source device that emits light; a light modulation device that modulates light from the light source device; a projection optical device according to any one of claims 1 to 3, which projects image light modulated by the light modulation device; A projector characterized by:

Images