Projector

Abstract

To suppress reduction in efficiency for light utilization of a projector.SOLUTION: The projector comprises: a first light source emitting linearly polarized first light; a first light condensing element condensing the first light emitted from the first light source; a first light guide member guiding the first light emitted from the first light condensing element; and a first liquid crystal panel modulating the first light emitted from the first light guide member. The first light guide member has: a first incidence surface to which the first light emitted from the first light condensing element is incident; a first light emission surface emitting the first light toward the first liquid crystal panel; and a first inclination part inclined to a first optical axis of the first light guide member and having a cross-sectional area increasing along a direction for guiding the first light. The first light emission surface of the first light guide member is in contact with a portion of a light incident side of the first liquid crystal panel. Alternatively, an air layer of 3 μm or less is provided between the first light emission surface and the portion of the light incident side of the first liquid crystal panel.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a projector.

Background Art

[0002] Conventionally, a projector including three liquid crystal panels, that is, a three-panel type projector, is known as a light modulation device that generates image light of each of the three primary colors. For example, Patent Document 1 discloses a three-panel type projector. The projector of Patent Document 1 includes three sets of illumination optical systems including a light source and a light guide rod, and three sets of liquid crystal panels in which a microlens array is disposed on the incident side. The light guide rod is disposed so as to face the microlens array with a gap therebetween.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the three-panel type projector disclosed in Patent Document 1, in a method of uniformly illuminating a liquid crystal panel using a tapered rod, the liquid crystal panel is cooled by leaving a space between the light guide rod and the liquid crystal panel and flowing air into the space. However, in the above-described three-panel type projector, there is a problem that a part of the illumination light leaks to the outside from the space due to the space provided between the light guide rod and the liquid crystal panel, resulting in a decrease in light utilization efficiency.

Means for Solving the Problems

[0005] A projector according to one aspect of the present invention includes a first light source that emits first linearly polarized light, a first condenser element that condenses the first light emitted from the first light source, a first light guide member that guides the first light emitted from the first condenser element, and a first liquid crystal panel that modulates the first light emitted from the first light guide member. The first light guide member has a first incident surface on which the first light emitted from the first condenser element is incident, a first emission surface that emits the first light toward the first liquid crystal panel, and a first inclined portion that is inclined with respect to the first optical axis of the first light guide member and has a cross-sectional area that increases in the direction of guiding the first light. The first emission surface of the first light guide member is in contact with a part of the first liquid crystal panel on the light incident side, or an air layer of 3 μm or less is provided between the first emission surface and a part of the first liquid crystal panel on the light incident side.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0007] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, the scale of dimensions may be changed depending on the component in order to make each component easier to view.

[0008] [First Embodiment] First, the first embodiment of the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is a schematic diagram of a projector 501 according to the first embodiment of the present invention. The projector 501 is an image display device including three liquid crystal panels as a light modulation device, and is a so-called three-panel type projector. As shown in FIG. 1, the projector 501 includes a blue light emitting unit 101, a green light emitting unit 102, a red light emitting unit 103, liquid crystal panels 351, 352, 353, a light combining member 200, a projection optical system 450, and cooling fans 481, 482, 483.

[0009] The blue light emitting unit 101 emits blue light LB. In the following description, an axis parallel to the optical axis of the blue light LB emitted from the blue light emitting unit 101 is defined as the Y direction. One side in the Y direction is defined as the -Y side, and the side opposite to the -Y side in the Y direction is defined as the +Y side. A direction orthogonal to the Y direction within a plane including the optical axis of the blue light LB is defined as the X direction. One side in the X direction is defined as the -X side, and the side opposite to the -X side in the X direction is defined as the +X side. A direction orthogonal to the X direction and the Y direction is defined as the Z direction. The Z direction corresponds to the height direction. The blue light LB in the blue light emitting unit 101 travels from the +Y side to the -Y side along the Y direction.

[0010] The blue light emitting unit 101 includes a light source 121, a collimating element 131, a condensing element 141, a diffusing device 151A, and a light guiding member 161. The blue light emitting unit 101 includes, for example, four light sources 121 in the X direction. The number of light sources 121 included in the blue light emitting unit 101 is appropriately set according to, for example, the ratio between the amount of light required for the blue light LB emitted from the blue light emitting unit 101 toward the light combining member 200 and the amount of light of the blue light LB emitted from one light source 121.

[0011] The light source 121 is supported by the substrate 111. The light source 121 is provided on the -Y side plate surface among the plate surfaces parallel to the XZ plane including the X direction and the Z direction on the substrate 111, and is arranged, for example, at intervals in the X direction. The substrate 111 is formed of, for example, metal, alloy, etc., but may be formed of an insulator such as resin. On the -Y side plate surface of the substrate 111, metal wirings and electrodes (not shown) are arranged. The metal wirings and electrodes provided on the substrate 111 are connected to the light source 121.

[0012] The light emitting surface of the light source 121 is arranged substantially parallel to the XZ plane, and is the surface on the opposite side in the Y direction from the surface in contact with the -Y side plate surface of the substrate 111 in the light source 121. The light source 121 corresponds to the first light source and emits blue light LB in the blue wavelength band in the visible wavelength band and linearly polarized. The blue light LB corresponds to the first light. The polarization direction of the blue light LB is along any one direction, and is parallel to, for example, the X direction or the Z direction. The blue light LB is, for example, P polarized light. The blue light LB is emitted from the light emitting surface of the light source 121, and diverges at an angle corresponding to the size of the light emitting surface and the peak wavelength of the blue light LB, etc., around the axis parallel to the Y direction passing through the center of the light emitting surface of the light source 121, and travels toward the -Y side. The blue wavelength band is, for example, a wavelength band of 420 nm to 500 nm.

[0013] The light source 121 is composed of, for example, a laser diode (LD) that emits blue light LB. When the blue light emitting unit 101 has a plurality of light sources 121, two or more light sources 121 may be arranged at intervals in the Z direction in addition to the X direction on the -Y side plate surface of the substrate 111, or may be arranged at intervals only in the Z direction.

[0014] The blue light emitting section 101 has the same number of collimating elements 131 as the light sources 121. One of the plurality of collimating elements 131 is arranged to correspond to one of the plurality of light sources 121. The collimating element 131 is arranged on the optical path of the blue light LB emitted from the light source 121 arranged in a one-to-one correspondence. The collimating element 131 is arranged at a position overlapping the light source 121 in the X direction and the Z direction, and is arranged on the -Y side of the light source 121. The incident surface of the collimating element 131 faces the emitting surface of the light source 121. The collimating element 131 collimates the blue light LB emitted in a radially divergent state about the optical axis parallel to the Y direction from the light source 121, and emits the collimated blue light LB to the -Y side along the Y direction.

[0015] The condensing element 141 is arranged at a position overlapping the region occupied by the same number of collimating elements 131 as the light sources 121 in the X direction and the Z direction, and is arranged on the -Y side of the collimating element 131. The condensing element 141 corresponds to the first condensing element. The condensing element 141 collects the light fluxes of the plurality of blue lights LB emitted along the Y direction from the collimating element 131, emits them to the -Y side along the Y direction, and condenses them on the optical axis in the XZ plane. The condensing element 141 is, for example, a plano-convex lens with a convex surface facing the incident side of the blue light LB, but may be an optical element other than a plano-convex lens such as a biconvex lens capable of condensing the incident blue light LB as described above.

[0016] The diffusion device 151A includes a diffusion substrate 152A and a driving device 153A. The diffusion substrate 152A has a diffusion surface along the XZ plane, is formed in a circular shape when viewed along the Y direction, and has an appropriate thickness in the Y direction. The center of the diffusion substrate 152A in the XZ plane is displaced from the optical axis of the blue light LB emitted from the condenser element 141. For example, it is arranged on the -X side of the optical axis of the blue light LB and is arranged at substantially the same position as the optical axis of the blue light LB in the Z direction. The optical axis of the blue light LB emitted from the condenser element 141 intersects the diffusion substrate 152A between a predetermined position shifted outward from the center in the radial direction with reference to the center of the diffusion substrate 152A in the XZ plane and the outer peripheral end. The aforementioned predetermined position corresponds to a position overlapping the outer edge of the driving device 153A when viewed along the Y direction in the radial direction with reference to the center of the diffusion substrate 152A in the XZ plane.

[0017] A fine concavo-convex structure designed according to the peak wavelength etc. of the incident color light is formed on the diffusion surface of the diffusion device 151A. The concavo-convex structure may be constituted by, for example, a microlens array composed of a plurality of microlenses, or may be formed by blasting. The shape of the concavo-convexities is not particularly limited as long as the incident blue light LB can be diffused in the XZ plane.

[0018] The driving device 153A is arranged on the -X side of the optical path of the blue light LB emitted from the condenser element 141, on the +Y side of the diffusion substrate 152A, and within a range overlapping the optical path of the blue light LB in the Z direction. The driving device 153A is connected to the diffusion substrate 152A coaxially with the rotation axis passing through the center of the XZ plane of the diffusion substrate 152A. The driving device 153A rotates the diffusion substrate 152A at a desired rotational speed in the circumferential direction around the rotation axis of the diffusion substrate 152A. The blue light LB incident on the diffusion substrate 152A from the +Y side converges near the diffusion surface of the diffusion substrate 152A in the Y direction, passes through the diffusion substrate 152A along the Y direction, and is diffused in the XZ plane. The diffused blue light LB is emitted from the diffusion substrate 152A to the -Y side and diverges in the XZ plane.

[0019] The light guide member 161 is disposed on the optical path of the blue light LB emitted from the diffusion substrate 152A of the diffusion device 151A, and is disposed on the -Y side of the diffusion substrate 152A. The light guide member 161 is formed to be long along the Y direction. The central axis of the light guide member 161 in the XZ plane is parallel to the Y direction and overlaps with the optical axis of the blue light LB emitted from the diffusion device 151A. The light guide member 161 corresponds to the first light guide member. The light guide member 161 guides the blue light LB emitted from the condensing element 141 and diffused by the diffusion device 151A to the -Y side, and makes it incident on the liquid crystal panel 351 for blue through the dust-proof glass 311. The detailed configuration of the light guide member 161 will be described later.

[0020] In the optical path of the blue light LB from the light emitting surface of the light source 121 in the blue light emitting unit 101 to the -Y side end surface of the light guide member 161, that is, the light emitting surface 161b described later, the polarization direction of the blue light LB is maintained. Specifically, the polarization direction of the blue light LB emitted from the light source 121 is parallel to the X direction, that is, the long side of the image formation region 355 of the liquid crystal panel 351 described later, or the Z direction, that is, parallel to the short side of the image formation region 355 of the liquid crystal panel 351. In the optical path of the blue light LB, for example, polarization maintaining type elements or members are applied to each of the collimating element 131, the condensing element 141, the diffusion substrate 152A of the diffusion device 151A, and the light guide member 161. Each of the collimating element 131, the condensing element 141, the diffusion substrate 152A, and the light guide member 161 may be formed of quartz, which is a material having excellent polarization maintaining properties, for example. In particular, the fact that the light guide member 161, which occupies a certain length in the optical path of the blue light LB in the blue light emitting unit 101, is formed of quartz is effective for maintaining the polarization direction of the blue light LB.

[0021] The liquid crystal panel 351 is provided on the optical path of the blue light LB emitted from the light guide member 161, is arranged at a position overlapping the light emitting surface 161b of the light guide member 161 in the X direction and the Z direction, and is arranged on the -Y side of the light guide member 161. The liquid crystal panel 351 corresponds to the first liquid crystal panel, and modulates the blue light LB emitted from the light guide member 161 and transmitted through the dustproof glass 311 based on the image information transmitted from an image forming device such as a computer (not shown) connected to the liquid crystal panel 351 from the outside, and generates blue image light IB.

[0022] The liquid crystal panel 351 is, for example, a transmissive liquid crystal panel. The liquid crystal panel 351 has an image forming region 355 in which a plurality of pixels (not shown in detail) are arranged along the X direction and the Z direction in the XZ plane. Each pixel includes a switching element. The switching element is, for example, a polysilicon thin film transistor (Thin Film Transistor; TFT). An electrical signal corresponding to the brightness of the blue light at the relative position of each pixel of the liquid crystal panel 351 in the image projected by the projector 501 is supplied to the switching element of each pixel. Each pixel of the liquid crystal panel 351 modulates the vibration direction of the blue light LB incident from the light guide member 161 through the dustproof glass 311 by the operation of the switching element according to the aforementioned electrical signal, and generates image light IB. The liquid crystal panel 351 emits the image light IB along the Y direction to the -Y side.

[0023] The dust-proof glass 311 has a plate surface parallel to the XZ plane, is disposed at a position overlapping with the light guide member 161 in the X and Z directions, and is disposed on the most +Y side in the liquid crystal panel 351. The plate surface on the +Y side of the dust-proof glass 311 is in contact with the end surface on the -Y side of the light guide member 161, that is, the light-emitting surface 161b. The dust-proof glass 311 prevents a substance that blocks the propagation of blue light LB such as dust to the photosynthesis member 200 from entering the pixel constituent portion of the liquid crystal panel 351 from the +Y side. The pixel constituent portion of the liquid crystal panel 351 will be described later. The dust-proof glass 311 is formed of a material that transmits at least light in the blue wavelength band in the visible wavelength band, and is preferably formed of a material having excellent heat dissipation properties. The dust-proof glass 313 is preferably formed of sapphire, which is a material excellent in light transmittance and heat dissipation properties, for example, but may be formed of quartz, optical glass, or the like.

[0024] The emission-side polarizing plate 361 is provided on the optical path of the image light IB emitted from the liquid crystal panel 351, is disposed at a position overlapping with the liquid crystal panel 351 in the X and Z directions, and is disposed on the most -Y side in the liquid crystal panel 351. The emission-side polarizing plate 361 has a plate surface parallel to the XZ plane. The plate surface on the +Y side of the emission-side polarizing plate 361 is in contact with, for example, the plate surface on the -Y side parallel to the XZ plane in the liquid crystal panel 351, that is, the light-emitting surface from which the image light IB is emitted to the -Y side. The emission-side polarizing plate 361 emits a predetermined polarization component of the image light IB emitted from the liquid crystal panel 351 to the -Y side along the Y direction, and shields components other than the predetermined polarization of the image light IB. The predetermined polarization is, for example, P polarization. That is, the predetermined polarization is linearly polarized light having a polarization direction in the Y direction or the X direction. The emission-side polarizing plate 361 is, for example, an absorption-type or reflection-type polarizing plate having a transmission axis with respect to the predetermined polarization. When it is desired to suppress the return light and stray light to the liquid crystal panel 351, it is preferable to use an absorption-type polarizing plate as the emission-side polarizing element 361.

[0025] The green light emitting unit 102 is disposed on the -X side and -Y side of the blue light emitting unit 101 and is disposed in a region overlapping the blue light emitting unit 101 in the Z direction. The green light emitting unit 102 emits green light LG. The green light LG in the green light emitting unit 102 travels from the -X side to the +X side along the X direction.

[0026] The green light emitting unit 102 includes a light source 122, a collimating element 132, a condensing element 142, a diffusing device 151B, and a light guiding member 162. The green light emitting unit 102 includes, for example, four light sources 122 in the Y direction. The number of light sources 122 included in the green light emitting unit 102 is appropriately set according to, for example, the ratio between the amount of green light LG required for the green light LG emitted from the green light emitting unit 102 toward the photosynthetic member 200 and the amount of green light LG emitted from one light source 122.

[0027] The light source 122 is supported by a substrate 112. The light source 122 is provided on the +X side plate surface among the plate surfaces parallel to the YZ plane including the Y direction and the Z direction on the substrate 112, and is arranged, for example, at intervals in the Y direction. The substrate 112 is formed of, for example, metal or alloy, but may be formed of an insulator such as resin like the substrate 111. Metal wirings and electrodes (not shown) are arranged on the +X side plate surface of the substrate 112. The metal wirings and electrodes provided on the substrate 112 are connected to the light source 122.

[0028] The light emitting surface of the light source 122 is arranged substantially parallel to the YZ plane, and is the surface on the opposite side in the X direction from the surface in contact with the +X side plate surface of the substrate 112 in the light source 122. The light source 122 corresponds to a second light source and emits green light LG in the green wavelength band in the visible wavelength band and linearly polarized. The green light LG corresponds to a second light. The polarization direction of the green light LG is along any one direction, and is parallel to, for example, the Y direction or the Z direction. The green light LG is, for example, P-polarized light. The green light LG is emitted from the light emitting surface of the light source 122, and diverges at an angle corresponding to the size of the light emitting surface and the peak wavelength of the green light LG, etc. around an axis parallel to the X direction passing through the center of the light emitting surface of the light source 122, and travels toward the +X side. The green wavelength band is, for example, a wavelength band of 520 nm to 620 nm.

[0029] The light source 122 is composed of, for example, an LD that emits green light LG. When the green light emitting unit 102 has a plurality of light sources 122, two or more light sources 122 may be arranged at intervals in the Z direction in addition to the Y direction on the plate surface on the +X side of the substrate 112, or may be arranged at intervals only in the Z direction.

[0030] The green light emitting unit 102 has the same number of collimating elements 132 as the light sources 122. One of the plurality of collimating elements 132 is arranged to correspond to one of the plurality of light sources 122. The collimating element 132 is arranged on the optical path of the green light LG emitted from the light source 122 arranged in a one-to-one correspondence. The collimating element 132 is arranged at a position overlapping the light source 122 in the Y direction and the Z direction, and is arranged on the +X side of the light source 122. The incident surface of the collimating element 132 faces the emitting surface of the light source 122. The collimating element 132 collimates the green light LG emitted in a radially divergent state around the optical axis parallel to the X direction from the light source 122, and emits the collimated green light LG to the +X side along the X direction.

[0031] The condensing element 142 is arranged at a position overlapping the region occupied by the same number of collimating elements 132 as the light sources 122 in the Y direction and the Z direction, and is arranged on the +X side of the collimating element 132. The condensing element 142 corresponds to the second condensing element. The condensing element 142 collects the light beams of the plurality of green lights LG emitted along the X direction from the collimating element 132, emits them to the +X side along the X direction, and condenses them on the optical axis in the YZ plane. The condensing element 142 is, for example, a plano-convex lens with a convex curved surface facing the incident side of the green light LG, but may be an optical element other than a plano-convex lens such as a biconvex lens that can condense the incident green light LG as described above.

[0032] The diffusion device 151B includes a diffusion substrate 152B and a driving device 153B. The diffusion substrate 152B has a diffusion surface along the YZ plane, is formed in a circular shape when viewed along the X direction, and has an appropriate thickness in the X direction. The center of the diffusion substrate 152B in the YZ plane is deviated from the optical axis of the green light LG emitted from the condenser element 142. For example, it is arranged on the +Y side of the optical axis of the green light LG and is arranged at substantially the same position as the optical axis of the green light LG in the Z direction. The optical axis of the green light LG emitted from the condenser element 142 intersects the diffusion substrate 152B between a predetermined position shifted outward from the center in the radial direction with respect to the center of the diffusion substrate 152B in the YZ plane and the outer peripheral end. The aforementioned predetermined position corresponds to a position overlapping the outer edge of the driving device 153B when viewed along the X direction in the radial direction with respect to the center of the diffusion substrate 152B in the YZ plane.

[0033] The driving device 153B is arranged on the +Y side of the optical path of the green light LG emitted from the condenser element 142, on the -X side of the diffusion substrate 152B, and within a range overlapping the optical path of the green light LG in the Z direction. The driving device 153B is connected to the diffusion substrate 152B coaxially with the rotation axis passing through the center of the YZ plane of the diffusion substrate 152B. The green light LG incident on the diffusion substrate 152B from the -X side converges near the diffusion surface of the diffusion substrate 152B in the X direction, passes through the diffusion substrate 152B along the X direction, and is diffused in the YZ plane. The diffused green light LG is emitted from the diffusion substrate 152B to the +X side and diverges in the YZ plane. A fine concavo-convex structure is formed on the diffusion surface of the diffusion substrate 152B, similar to the diffusion surface of the diffusion substrate 152A.

[0034] The light guide member 162 is provided on the optical path of the green light LG emitted from the diffusion substrate 152B of the diffusion device 151B, and is disposed on the +X side with respect to the diffusion substrate 152B. The light guide member 162 is formed to be long along the X direction. The central axis of the light guide member 162 on the YZ plane is parallel to the X direction and overlaps with the optical axis of the green light LG emitted from the diffusion device 151B. The light guide member 162 corresponds to the second light guide member. The light guide member 162 guides the green light LG emitted from the condensing element 142 and diffused by the diffusion device 151B to the +X side, and causes it to enter the liquid crystal panel 352 for green through the dust-proof glass 312.

[0035] In the optical path of the green light LG from the light emitting surface of the light source 122 in the green light emitting unit 102 to the end face on the +X side of the light guide member 162, that is, the light emitting face 162b, the polarization direction of the green light LG is maintained. Specifically, the polarization direction of the green light LG emitted from the light source 122 is parallel to the Y direction, that is, the direction parallel to the long side of the image formation region 356 of the liquid crystal panel 352 described later, or the Z direction, that is, the direction parallel to the short side of the image formation region 356 of the liquid crystal panel 352. In the optical path of the green light LG, polarization maintaining type elements or members are applied to each of the collimating element 132, the condensing element 142, the diffusion substrate 152B of the diffusion device 151B, and the light guide member 162. Each of the collimating element 132, the condensing element 142, the diffusion substrate 152B, and the light guide member 162 may be formed of quartz, which is a material having excellent polarization maintaining properties, for example. In particular, the fact that the light guide member 162, which occupies a certain length in the optical path of the green light LG in the green light emitting unit 102, is formed of quartz is effective for maintaining the polarization direction of the green light LG.

[0036] The liquid crystal panel 352 is provided on the optical path of the green light LG emitted from the light guide member 162, is disposed at a position overlapping the light emitting surface 162b of the light guide member 162 in the Y direction and the Z direction, and is disposed on the +X side of the light guide member 162. The liquid crystal panel 352 corresponds to the second liquid crystal panel, and modulates the green light LG emitted from the light guide member 162 and transmitted through the dust-proof glass 312 based on image information transmitted from an image forming device such as a computer (not shown) connected to the liquid crystal panel 352 from the outside, and generates green image light IG.

[0037] The liquid crystal panel 352 is, for example, a transmissive liquid crystal panel. The liquid crystal panel 352 has an image forming region 356 in which a plurality of pixels (not shown) are arranged along the Y direction and the Z direction on the YZ plane. Each pixel includes a switching element such as a TET. An electrical signal corresponding to the brightness of the green light at the relative position of each pixel of the liquid crystal panel 352 in the image projected by the projector 501 is supplied to the switching element of each pixel. Each pixel of the liquid crystal panel 352 modulates the vibration direction of the green light LG incident from the light guide member 162 through the dust-proof glass 312 by the operation of the switching element according to the aforementioned electrical signal, and generates image light IG. The liquid crystal panel 352 emits the image light IG in the +X direction along the X direction.

[0038] The dust-proof glass 312 has a plate surface parallel to the YZ plane, is disposed at a position overlapping the light guide member 162 in the Y direction and the Z direction, and is disposed on the most -X side in the liquid crystal panel 352. The -X side plate surface of the dust-proof glass 312 is in contact with the +X side end surface of the light guide member 162, that is, the light emitting surface 162b. The dust-proof glass 312 prevents a substance that blocks the propagation of the green light LG such as dust from entering the liquid crystal panel 352. The dust-proof glass 312 is formed of a material that transmits at least light in the green wavelength band among the visible wavelength bands, and is preferably formed of a material having excellent heat dissipation properties. The dust-proof glass 312 is preferably formed of sapphire, which is a material having excellent light transmittance and heat dissipation properties, for example, but may also be formed of quartz, optical glass, or the like.

[0039] The emission-side polarizing plate 362 is provided on the optical path of the image light IG emitted from the liquid crystal panel 352, is disposed at a position overlapping the liquid crystal panel 352 in the Y direction and the Z direction, and is disposed on the most +X side of the liquid crystal panel 352. The emission-side polarizing plate 362 has a plate surface parallel to the YZ plane. The -X side plate surface of the emission-side polarizing plate 362 is in contact with, for example, the +X side plate surface parallel to the YZ plane in the liquid crystal panel 352, that is, the emission surface from which the image light IG is emitted to the +X side. The emission-side polarizing plate 362 emits a predetermined polarization component of the image light IG emitted from the liquid crystal panel 352 to the +X side along the X direction, and shields components other than the predetermined polarization of the image light IG. The predetermined polarization is, for example, P polarization. The emission-side polarizing plate 362 is, for example, an absorption-type or reflection-type polarizing plate having a transmission axis for the predetermined polarization. When it is desired to suppress the return light and stray light to the liquid crystal panel 352, it is preferable to use an absorption-type polarizing plate as the emission-side polarizing element 362.

[0040] The red light emission unit 103 is disposed in a region overlapping the blue light emission unit 101 in the X direction and the Z direction, and is disposed on the +X side of the green light emission unit 102. The red light emission unit 103 emits red light LR. The red light LG in the red light emission unit 103 travels from the -Y side to the +Y side along the Y direction.

[0041] The red light emission unit 103 includes a light source 123, a collimating element 133, a condensing element 143, a diffusing device 151C, and a light guide member 163. The red light emission unit 103 includes, for example, four light sources 123 in the X direction. The number of light sources 123 included in the red light emission unit 103 is appropriately set according to, for example, the ratio between the amount of red light LR required for the red light LR emitted from the red light emission unit 103 toward the photosynthesis member 200 and the amount of red light LR emitted from one light source 123.

[0042] The light source 123 is supported by the substrate 113. The light source 123 is provided on the +Y side plate surface among the plate surfaces parallel to the XZ plane on the substrate 113, and is, for example, arranged at intervals in the Y direction. The substrate 113 is formed of, for example, metal, alloy, etc., but may be formed of an insulator such as resin like the substrates 111 and 112. Metal wirings and electrodes (not shown) are arranged on the +Y side plate surface of the substrate 113. The metal wirings and electrodes provided on the substrate 113 are connected to the light source 123.

[0043] The light emitting surface of the light source 123 is arranged substantially parallel to the XZ plane, and is the surface on the opposite side in the Y direction from the surface that contacts the +Y side plate surface of the substrate 113 in the light source 123. The light source 123 corresponds to the third light source and emits red light LR in the red wavelength band in the visible wavelength band and linearly polarized red light. The red light LR corresponds to the third light. The polarization direction of the red light LR is parallel to the X direction or the Z direction. The red light LR is, for example, P-polarized light. The red light LR is emitted from the light emitting surface of the light source 123, and diverges at an angle corresponding to the size of the light emitting surface and the peak wavelength of the red light LR, etc. around the axis parallel to the Y direction passing through the center of the light emitting surface of the light source 123, and travels in the +Y direction. The red wavelength band is, for example, a wavelength band of 600 nm to 680 nm.

[0044] The light source 123 is composed of, for example, an LD that emits red light LR. When the red light emitting unit 103 has a plurality of light sources 123, two or more light sources 123 may be arranged at intervals in the Z direction in addition to the X direction on the +Y side plate surface of the substrate 113, or may be arranged at intervals only in the Z direction.

[0045] The red light emitting unit 103 has the same number of collimating elements 133 as the light sources 123. One of the plurality of collimating elements 133 is arranged to correspond to one of the plurality of light sources 123. The collimating element 133 is arranged on the optical path of the red light LR emitted from the light source 123 arranged in a one-to-one correspondence. The collimating element 133 is arranged at a position overlapping the light source 123 in the X direction and the Z direction, and is arranged on the +Y side of the light source 123. The incident surface of the collimating element 133 faces the emission surface of the light source 123. The collimating element 133 collimates the red light LR emitted in a radially diverging state around the optical axis parallel to the Y direction from the light source 123, and emits the collimated red light LR to the +Y side along the Y direction.

[0046] The condensing element 143 is arranged at a position overlapping the region occupied by the same number of collimating elements 133 as the light sources 123 in the X direction and the Z direction, and is arranged on the +Y side of the collimating element 133. The condensing element 143 corresponds to the third condensing element. The condensing element 143 collects the light fluxes of the plurality of red lights LR emitted along the Y direction from the collimating element 133, emits them to the +Y side along the Y direction, and condenses them on the optical axis in the XZ plane. The condensing element 143 is, for example, a plano-convex lens with a convex surface facing the incident side of the red light LR, but may be an optical element other than a plano-convex lens such as a biconvex lens capable of condensing the incident red light LR as described above.

[0047] The diffusion device 151C includes a diffusion substrate 152C and a driving device 153C. The diffusion substrate 152C has a diffusion surface along the XZ plane, is formed in a circular shape when viewed along the Y direction, and has an appropriate thickness in the Y direction. The center of the diffusion substrate 152C in the XZ plane is offset from the optical axis of the red light LR emitted from the condenser element 143. For example, it is arranged on the -X side of the optical axis of the red light LR and is arranged at substantially the same position as the optical axis of the red light LR in the Z direction. The optical axis of the red light LR emitted from the condenser element 143 intersects the diffusion substrate 152C between a predetermined position that has moved outward from the center in the radial direction with respect to the center of the XZ plane of the diffusion substrate 152C and the outer peripheral end. The aforementioned predetermined position corresponds to a position that overlaps with the outer edge of the driving device 153C when viewed along the Y direction in the radial direction with respect to the center of the XZ plane of the diffusion substrate 152C.

[0048] The driving device 153C is arranged on the -X side of the optical path of the red light LR emitted from the condenser element 143, on the -X side of the diffusion substrate 152C, and within a range that overlaps the optical path of the red light LR in the Z direction. The driving device 153C is connected to the diffusion substrate 152C coaxially with the rotation axis passing through the center of the XZ plane of the diffusion substrate 152C. The red light LR incident on the diffusion substrate 152C from the -Y side converges near the diffusion surface of the diffusion substrate 152C in the Y direction, passes through the diffusion substrate 152C along the Y direction, and is diffused in the XZ plane. The diffused red light LR is emitted from the diffusion substrate 152C to the +Y side and diverges in the XZ plane. A fine uneven structure is formed on the diffusion surface of the diffusion substrate 152C, similar to the diffusion surface of the diffusion substrate 151A.

[0049] The light guide member 163 is provided on the optical path of the red light LR emitted from the diffusion substrate 152C of the diffusion device 151C, and is disposed on the +Y side of the diffusion substrate 152C. The light guide member 163 is formed to be long along the Y direction. The central axis of the light guide member 163 in the XZ plane is parallel to the Y direction and overlaps with the optical axis of the red light LR emitted from the diffusion device 151C. The light guide member 163 corresponds to the third light guide member. The light guide member 163 guides the red light LR emitted from the condensing element 143 and diffused by the diffusion device 151C to the +Y side, and makes it incident on the liquid crystal panel 353 for red through the dust-proof glass 313.

[0050] In the optical path of the red light LR from the light emitting surface of the light source 123 in the red light emitting section 103 to the end face on the +Y side of the light guide member 163, that is, the light emitting face 163b, the polarization direction of the red light LR is maintained. Specifically, the polarization direction of the red light LR emitted from the light source 123 is parallel to the X direction, that is, the direction parallel to the long side of the image formation region 357 of the liquid crystal panel 353 described later, or the Z direction, that is, the direction parallel to the short side of the image formation region 357 of the liquid crystal panel 353. In the optical path of the red light LR, polarization maintaining type elements or members are applied to the collimating element 133, the condensing element 143, the diffusion substrate 152C of the diffusion device 151C, and the light guide member 163, which are disposed at a stage subsequent to the light source 123, respectively. Each of the collimating element 133, the condensing element 143, the diffusion substrate 152C, and the light guide member 163 may be formed of quartz, which is a material having excellent polarization maintaining properties, for example. In particular, the fact that the light guide member 163, which occupies a certain length in the optical path of the red light LR in the red light emitting section 103, is formed of quartz is effective for maintaining the polarization direction of the red light LR.

[0051] The liquid crystal panel 353 is provided on the optical path of the red light LR emitted from the light guide member 163, is disposed at a position overlapping the light emitting surface 163b of the light guide member 163 in the X direction and the Z direction, and is disposed on the +Y side of the light guide member 163. The liquid crystal panel 353 corresponds to the third liquid crystal panel, and modulates the red light LR emitted from the light guide member 163 and transmitted through the dustproof glass 313 based on image information transmitted from an image forming device such as a computer (not shown) connected to the liquid crystal panel 353 from the outside to generate red image light IR.

[0052] The liquid crystal panel 353 is, for example, a transmissive liquid crystal panel. The liquid crystal panel 353 has an image forming region 357 in which a plurality of pixels (not shown) are arranged along the X direction and the Z direction in the XZ plane. Each pixel includes a switching element such as a TET. An electrical signal corresponding to the brightness of the red light at the relative position of each pixel of the liquid crystal panel 353 in the image projected by the projector 501 is supplied to the switching element of each pixel. Each pixel of the liquid crystal panel 353 modulates the vibration direction of the red light LR incident from the light guide member 163 through the dustproof glass 313 by the operation of the switching element according to the aforementioned electrical signal to generate image light IR. The liquid crystal panel 353 emits the image light IR in the +Y direction along the Y direction.

[0053] The dustproof glass 313 has a plate surface parallel to the XZ plane, is disposed at a position overlapping the light guide member 163 in the X direction and the Z direction, and is disposed on the most -Y side in the liquid crystal panel 353. The -Y side plate surface of the dustproof glass 313 is in contact with the +Y side end surface of the light guide member 163, that is, the light emitting surface 163b. The dustproof glass 313 prevents substances that block the propagation of the red light LR such as dust from entering the liquid crystal panel 353. The dustproof glass 313 is formed of a material that transmits at least light in the red wavelength band in the visible wavelength band, and is preferably formed of a material with excellent heat dissipation. The dustproof glass 313 is preferably formed of sapphire, which is a material with excellent light transmittance and heat dissipation, for example, but may also be formed of quartz, optical glass, or the like.

[0054] The emission-side polarizing plate 363 is provided on the optical path of the image light IR emitted from the liquid crystal panel 353, is disposed at a position overlapping the liquid crystal panel 353 in the X direction and the Z direction, and is disposed on the most +Y side in the liquid crystal panel 353. The emission-side polarizing plate 363 has a plate surface parallel to the XZ plane. The plate surface on the -Y side of the emission-side polarizing plate 363 is in contact with, for example, the plate surface on the +Y side parallel to the XZ plane in the liquid crystal panel 353, that is, the emission surface from which the image light IR is emitted to the +Y side. The emission-side polarizing plate 363 emits a predetermined polarization component of the image light IR emitted from the liquid crystal panel 353 to the +Y side along the Y direction, and blocks components other than the predetermined polarization of the image light IR. The predetermined polarization is, for example, P polarization. The emission-side polarizing plate 363 is, for example, an absorption-type or reflection-type polarizing plate having a transmission axis for the predetermined polarization. When it is desired to suppress the return light and stray light to the liquid crystal panel 353, it is preferable to use an absorption-type polarizing plate as the emission-side polarizing element 363.

[0055] The light synthesizing member 200 is disposed in a region where the optical path of the blue image light IB emitted from the emission-side polarizing plate 361, the optical path of the green image light IG emitted from the emission-side polarizing plate 362, and the optical path of the red image light IR emitted from the emission-side polarizing plate 363 intersect. The light synthesizing member 200 synthesizes the image lights IB, IG, and IR, and emits the generated image light IM to the +X side along the X direction.

[0056] The light synthesizing member 200 is, for example, a cross dichroic prism 210. The cross dichroic prism 210 has an incident surface 210c facing the emission surface of the emission-side polarizing plate 361, an incident surface 210d facing the emission surface of the emission-side polarizing plate 362, an incident surface 210e facing the emission surface of the emission-side polarizing plate 363, an emission surface 210b, and two reflection films 211 and 212. The incident surfaces 210c and 210e are parallel to the XZ plane and overlap each other in the X direction and the Z direction. The incident surface 210e is located on the -Y side of the incident surface 210c. The incident surface 210d and the emission surface 210b are parallel to the YZ plane and overlap each other in the Y direction and the Z direction. The emission surface 210b is located on the +X side of the incident surface 210d and on the +X side of the incident surfaces 210c and 210e.

[0057] The reflective film 211 is arranged such that when viewed along the Z direction, it moves from the +X side to the -X side as it moves from the -Y side to the +Y side. The reflective film 212 is arranged such that when viewed along the Z direction, it moves from the -X side to the +X side as it moves from the -Y side to the +Y side. The reflective films 211 and 212 overlap the incident surfaces 210c and 210e in the X direction, overlap the incident surface 210d and the exit surface 210b in the Y direction, and overlap the incident surfaces 210c, 210d, 210e and the exit surface 210b in the Z direction. The reflective film 211 reflects light in the blue wavelength band and transmits light in the green and red wavelength bands. The reflective film 212 reflects light in the red wavelength band and transmits light in the blue and green wavelength bands.

[0058] The cross-dichroic prism 210 is formed of a transparent material that transmits light in the visible wavelength band. The reflective films 211 and 212 are constituted by, for example, dielectric multilayer films.

[0059] A predetermined polarization of the image light IB emitted from the exit-side polarizing plate 361 travels along the Y direction to the -Y side, enters the cross-dichroic prism 210 from the incident surface 210c, passes through the reflective film 212, is reflected by the reflective film 211, is deflected in the X direction, and travels to the +X side. A predetermined polarization of the image light IG emitted from the exit-side polarizing plate 362 travels along the X direction to the +X side, enters the cross-dichroic prism 210 from the incident surface 210d, passes through the reflective films 211 and 212, and travels straight to the +X side. A predetermined polarization of the image light IR emitted from the exit-side polarizing plate 363 travels along the Y direction to the +Y side, enters the cross-dichroic prism 210 from the incident surface 210e, passes through the reflective film 211, is reflected by the reflective film 212, is deflected in the X direction, and travels to the +X side.

[0060] The image lights IB, IG, and IR emitted from the reflection films 211 and 212 of the cross-dichroic prism 210 to the +X side are synthesized with each other, and a full-color image light IM is generated. The cross-dichroic prism 210 emits the image light IM from the emission surface 210b along the X direction to the +X side.

[0061] The projection optical system 450 is disposed on the optical path of the image light IM emitted from the light synthesis member 200. The projection optical system 450 projects the image light IM onto a screen SC disposed on the +X side of the projection optical system 450, and enlarges and displays the image transmitted from an image forming apparatus (not shown) to the liquid crystal panels 351, 352, and 353 on the screen SC. The projection optical system 450 is constituted by, for example, one or more optical lenses arranged along the X direction. The optical lenses include, for example, a plano-convex lens, a plano-concave lens, a biconvex lens, a biconcave lens, a meniscus lens, an aspherical lens, a free-form surface lens, and the like.

[0062] Next, taking the blue light emission unit 101 as an example, the configuration of the light guide member of each color light emission unit and the like will be described. FIG. 2 is an enlarged view of a part of the projector 501, and is a schematic view when the blue light emission unit 101 and the liquid crystal panel 351 are viewed from the +X side toward the -X side along the X direction. In FIG. 2, the substrate 111 is omitted.

[0063] As shown in FIG. 2, the light guide member 161 has an incident surface 161a, an emission surface 161b, and a side surface 161s connecting the incident surface 161a and the emission surface 161b.

[0064] The incident surface 161a is an end surface on the +Y side of the light guide member 161, is parallel to the XZ plane, and is substantially similar to the spot shape of the blue light LB condensed by the condenser element 141 in the present embodiment. Note that the shape of the incident surface 161a does not have to be similar to the spot shape of the blue light LB. The shape of the incident surface 161a when viewed along the Y direction is, for example, a rectangular shape having a long side parallel to the X direction and a short side parallel to the Z direction, but may be a square shape.

[0065] The emitting surface 161b is the -Y side end face of the light guide member 161, is parallel to the XZ plane, and is substantially similar to the shape of the image forming region 355 of the liquid crystal panel 351. The shape of the emitting surface 161b when viewed along the Y direction is, for example, a rectangular shape having a long side parallel to the X direction and a short side parallel to the Z direction. The dimension of the image forming region 355 in the X direction is larger than the dimension of the image forming region 355 in the Z direction. The aspect ratio of the dimension of the emitting surface 161b in the X direction to the dimension in the Z direction corresponds to the aspect ratio of the dimension of the image forming region 355 in the X direction to the dimension in the Z direction, and is, for example, 3:4, 4:5, 9:16, etc.

[0066] The virtual line connecting the center of the incident surface 161a and the center of the emitting surface 161b is substantially parallel to the Y direction. The dimension of the emitting surface 161b in the X direction of the emitting surface 161b is larger than the dimension of the incident surface 161a in the X direction. The dimension of the emitting surface 161b in the Z direction is larger than the dimension of the incident surface 161a in the Z direction. The area of the emitting surface 161b is larger than the area of the incident surface 161a.

[0067] The light guide member 161 has four side surfaces 161s. Among the four side surfaces 161s, the first side surface 161s connects the +Z-side long side of the two long sides parallel to the X direction of the incident surface 161a and the +Z-side long side of the two long sides parallel to the X direction of the emission surface 161b, and has a trapezoidal shape when viewed from a direction orthogonal to the first side surface 161s. Among the four side surfaces 161s, the second side surface 161s connects the -Z-side long side of the two long sides parallel to the X direction of the incident surface 161a and the -Z-side long side of the two long sides parallel to the X direction of the emission surface 161b, and has a trapezoidal shape when viewed from a direction orthogonal to the second side surface 161s. Among the four side surfaces 161s, the third side surface 161s connects the +X-side long side of the two short sides parallel to the Z direction of the incident surface 161a and the +X-side short side of the two short sides parallel to the Z direction of the emission surface 161b, and has a trapezoidal shape when viewed from a direction orthogonal to the third side surface 161s. Among the four side surfaces 161s, the fourth side surface 161s connects the -X-side long side of the two short sides parallel to the Z direction of the incident surface 161a and the -X-side short side of the two short sides parallel to the Z direction of the emission surface 161b, and has a trapezoidal shape when viewed from a direction orthogonal to the fourth side surface 161s.

[0068] Each of the four side surfaces 161s is inclined in the Y direction as a whole with respect to the optical axis AX1 of the blue light LB in the light guide member 161. The optical axis AX1 corresponds to the first optical axis. The inclination angle of the side surface 161s with respect to the optical axis AX1 is a so-called taper angle, which is determined by the dimensions of the incident surface 161a and the emission surface 161b, and the length of the light guide member 161 in the Y direction.

[0069] FIG. 3 is a perspective view of the light guide member 161. As shown in FIG. 3, the light guide member 161 is a solid frustum of a square pyramid surrounded by an incident surface 161a, an exit surface 161b, and four side surfaces 161s. The solid light guide member 161 is made of a transparent material that has light transmittance and heat dissipation properties with respect to the blue light LB as described above, can well maintain the polarization direction of the blue light LB, and has an appropriately high refractive index with respect to the air around the light guide member 161. The incident surface 161a corresponds to the upper surface of the frustum of the square pyramid. The exit surface 161b corresponds to the bottom surface of the frustum of the square pyramid. The length of the light guide member 161 in the Y direction corresponds to the height of the frustum of the square pyramid.

[0070] The light guide member 161 is composed of an incident surface 161a, an exit surface 161b, and an inclined portion 161t. The inclined portion 161t connects the incident surface 161a and the exit surface 161b in the Y direction and is surrounded by the four side surfaces 161s in the XZ plane. The central axes of the frustum of the square pyramid-shaped light guide member 161 and the inclined portion 161t are parallel to the Y direction and parallel to the entire optical axis AX1 of the blue light LB that enters the incident surface 161a from the +Y side, is totally reflected by the side surface 161s, and propagates through the inclined portion 161t. As described above, since the exit surface 161b is larger than the incident surface 161a and the centers of the incident surface 161a and the exit surface 161b overlap each other in the XY plane, the area of the cross-section parallel to the XZ plane that intersects the Y direction and the optical axis AX1 of the inclined portion 161t, that is, the cross-sectional area of the inclined portion 161t, increases as it advances from the +Y side to the -Y side.

[0071] Returning to FIG. 1, the blue light LB that is condensed by the condensing element 141 and emitted from the diffusion substrate 152A of the diffusion device 151A enters the light guide member 161 as described above. The blue light LB enters the incident surface 161a of the light guide member 161 along the Y direction from the +Y side. At this time, the blue light LB diverges around the optical axis parallel to the Y direction. Therefore, the incident angle of the blue light LB to the incident surface 161a and the angle formed with respect to the optical axis of the blue light LB that enters the inside of the light guide member 161 from the incident surface 161a are not constant and have a range corresponding to the power of the condensing element 141 and the like.

[0072] As described above, the light guide member 161 is formed of a transparent member having a refractive index higher than that of the surrounding air. Among the blue light LB incident from the incident surface 161a into the light guide member 161, the blue light LB whose angle with respect to the optical axis AX1 is equal to or less than the taper angle of the side surface 161s directly reaches the emission surface 161b. Among the blue light LB incident from the incident surface 161a into the light guide member 161, the blue light LB whose angle with respect to the optical axis AX1 is larger than the taper angle of the side surface 161s is totally reflected by the side surface 161s and reaches the emission surface 161b. When the blue light LB is totally reflected by the side surface 161s, the amount of the reflected blue light LB is improved as compared with the case where it is reflected by a reflection film made of a dielectric multilayer film or the like (not shown) at the side surface 161s. The number of times the blue light LB whose angle with respect to the optical axis AX1 is larger than the taper angle of the side surface 161s is totally reflected by the side surface 161b varies depending on the angle with respect to the optical axis AX1. At the emission surface 161b, as a result of the blue light LB having different paths and incident angles entering, the illuminance distribution of the blue light LB is made uniform.

[0073] The blue light LB whose illuminance distribution is made uniform in the XZ plane is emitted from the emission surface 161b toward the -Y side and directly enters the dust-proof glass 311. The size of the emission surface 161b in the XZ plane is ensured to be wider than the image formation region 355 by the amount of the illumination margin around the image formation region 355 of the liquid crystal panel 351. The illumination margin in the blue light emission unit 101 depends on the sizes of the dust-proof glass 311 and the counter substrate 391 in the Y direction, that is, the thickness of the dust-proof glass 311 and the thickness of the counter substrate 391.

[0074] In order to efficiently totally reflect the blue light LB at the side surface 161s in the light guide member 161 and to make the illuminance distribution of the blue light LB uniform at the emission surface 161b, the taper angle of the side surface 161s is appropriately set according to the refractive index of the transparent material of the light guide member 161 and the like. Examples of the transparent material of the light guide member 161 include quartz, optical glass, etc. as described above, and quartz is preferable because of its excellent light transmittance and polarization retention. When the light guide member 161 is formed of quartz, the taper angle of the side surface 161s is, for example, about 9° to 12°.

[0075] As shown in FIG. 2, the liquid crystal panel 351 includes a dustproof glass 311, a counter substrate 391, a liquid crystal layer 392, an element substrate 393, and an emission-side polarizing plate 361, which are sequentially stacked and arranged from the +Y side to the -Y side in the Y direction. The dustproof glass 311 is disposed on the incident side of blue light LB with respect to the counter substrate 391 and corresponds to an incident-side dustproof member. The counter substrate 391, the liquid crystal layer 392, and the element substrate 393 are pixel configuration portions of the liquid crystal panel 351 and constitute a plurality of pixels.

[0076] The plate surface of the dustproof glass 311 is larger than the emission surface 161b of the light guide member 161 in the X and Z directions. The +Z side end of the dustproof glass 311 is located further on the +Z side than the +Z side end of the emission surface 161b of the light guide member 161 and the +Z side end of the liquid crystal panel 351. The -Z side end of the dustproof glass 311 is located further on the -Z side than the -Z side end of the emission surface 161b of the light guide member 161 and the -Z side end of the liquid crystal panel 351. Similarly, the ±X side ends of the dustproof glass 311 are located further on the ±X side than the ±X side ends of the emission surface 161b of the light guide member 161 and the ±X side ends of the liquid crystal panel 351. The center of the plate surface of the dustproof glass 311 overlaps the optical axis AX1 of the blue light LB.

[0077] The counter substrate 391 corresponds to the first substrate. The plate surface of the counter substrate 391 is slightly larger than the emission surface 161b of the light guide member 161 in the X and Z directions, smaller than the plate surface of the dustproof glass 311, and at least larger than the image formation region 355. The center of the plate surface of the counter substrate 391 overlaps the optical axis AX1 of the blue light LB. The +Y side plate surface of the counter substrate 391 is in contact with the -Y side plate surface of the dustproof glass 311. Counter electrodes and the like corresponding to each of the plurality of pixels are formed on the -Y side plate surface of the counter substrate 391.

[0078] The liquid crystal layer 392 is disposed in the image forming region 355 of the liquid crystal panel 351, is arranged in a rectangular shape that constitutes the image forming region 355 when viewed along the Y direction, and is sandwiched between the counter substrate 391 and the element substrate 393 in the Y direction. The liquid crystal layer 392 contains a plurality of liquid crystal molecules (not shown). Around the liquid crystal layer 392 in the XZ plane, there are arranged layer structures (not shown) that constitute the peripheral region of the electro-optical device constituting the liquid crystal panel 351, and a sealing material (not shown) for sealing the liquid crystal layer 392 within the image forming region 355.

[0079] The element substrate 393 corresponds to the second substrate. The plate surface of the element substrate 393 has the same size as the counter substrate 391 in the X direction and the Z direction, and overlaps the counter substrate 391 when viewed along the Y direction. The center of the plate surface of the element substrate 393 overlaps the optical axis AX1 of the blue light LB. On the -Y side plate surface of the element substrate 393, pixel electrodes corresponding to each of a plurality of pixels, TFTs constituting switching elements, a liquid crystal alignment film, etc. are formed. The +Y side plate surface of the element substrate 393 is in contact with the -Y side plate surface of the emission side polarizing plate 361. The element substrate 393 and the counter substrate 391 are formed to have the same size and rectangular shape as each other when viewed along the Y direction, and are formed larger than the image forming region 355 in each of the X direction and the Z direction. The element substrate 393 and the counter substrate 391 sandwich and support the liquid crystal layer 392 and the peripheral region structure including layer structures and sealing materials (not shown) that constitute the peripheral region (not shown) in the Y direction.

[0080] The emission side polarizing plate 361 is disposed on the emission side of the blue light LB with respect to the element substrate 393. The plate surface of the emission side polarizing plate 361 has the same size as the counter substrate 391 and the element substrate 393 in the X direction and the Z direction, and overlaps the counter substrate 391 and the element substrate 393 when viewed along the Y direction. The center of the plate surface of the emission side polarizing plate 361 overlaps the optical axis AX1 of the blue light LB. By disposing the emission side polarizing plate 361, it is possible to prevent substances that block the propagation of the blue light LB, such as dust, from entering the pixel constituent portion of the liquid crystal panel 351 from the -Y side into the photosynthesis member 200. The emission side polarizing plate 361 corresponds to the emission side dust-proof member.

[0081] FIG. 4 is an image showing the result of calculating, by numerical simulation, the illuminance distribution on the incident surface on the +Y side of the liquid crystal layer 392 of the liquid crystal panel 351 when parameters regarding the dimensions and materials of each element and the light guide member 161 in the blue light emitting unit 101 having the above-described configuration are appropriately set. FIG. 5 is an image showing the result of calculating, by numerical simulation, the illuminance distribution on the incident surface on the +Y side of the liquid crystal layer 392 of the liquid crystal panel 351 when the length of the light guide member 161 in the Y direction is reduced and the light emitting surface 161b of the light guide member 161 is moved to the +Y side under the same conditions as the numerical simulation for obtaining the image of FIG. 4. The setting of the numerical simulation for obtaining the image of FIG. 5 is the same as the setting of the numerical simulation for obtaining the image of FIG. 4 in a state where a gap having a distance greater than at least 3 μm in the Y direction is provided between the light emitting surface 161b of the light guide member 161 and the plate surface on the +Y side of the dust-proof glass 311.

[0082] In each of the image of FIG. 4 and the image of FIG. 5, there are an effective irradiation portion LAA and a peripheral portion LAC. The effective irradiation portion LAA is a portion including the central portion of the irradiation region of the blue light LB on the XZ plane, and means a portion where the illuminance of the blue light LB within a predetermined illuminance range to be irradiated to the image formation region 355 of the liquid crystal panel 351 is obtained. The peripheral portion LAC is generated around the effective irradiation portion LAA on the XZ plane, and means a portion where the illuminance of the blue light LB is lower than the above-described predetermined illuminance range.

[0083] In the blue light emitting unit 101 and the projector 501 of the first embodiment, since the light emitting surface 161b of the light guide member 161 is in contact with the plate surface on the +Y side of the dust-proof glass 311, the separation distance in the Y direction between the light emitting surface 161b and the incident surface on the +Y side of the liquid crystal layer 392 of the liquid crystal panel 351 is suppressed to be equal to the sum of the dimension in the Y direction of the dust-proof glass 311, that is, the thickness, and the dimension in the Y direction of the counter substrate 391 of the liquid crystal layer 392, that is, the thickness. As can be seen from the comparison between the image of FIG. 4 and the image of FIG. 5, in the configuration of the blue light emitting unit 101 and the projector 501 shown in FIG. 4, a relatively wide effective irradiation portion LAA of the blue light LB is ensured, and the peripheral portion LAC is relatively suppressed to be narrow.

[0084] As shown in FIG. 5, similar to the conventional projector, when a gap is generated between the light-emitting surface 161b of the light guide member 161 and the +Y-side plate surface of the dust-proof glass 311, it was confirmed that the effective irradiation portion LAA of the blue light LB becomes relatively narrow and the peripheral portion LAC relatively spreads. When a gap is generated between the light-emitting surface 161b of the light guide member 161 and the +Y-side plate surface of the dust-proof glass 311, in order to obtain the effective irradiation portion LAA having the same dimensions and area as in the case where no gap is generated as in the first embodiment, it is necessary to expand the light-emitting surface 161b of the light guide member 161 in the X direction and the Z direction. If the taper angle of the side surface 161s of the light guide member 161 is substantially constant, an increase in the size of the light guide member 161 is required. Further, when a gap is generated between the light-emitting surface 161b of the light guide member 161 and the +Y-side plate surface of the dust-proof glass 311, since the peripheral portion LAC is relatively wide with respect to the irradiation region of the blue light LB as compared with the case where no gap is generated, the utilization efficiency of the blue light LB may decrease.

[0085] From the results of the above numerical simulation, since the light-emitting surface 161b of the light guide member 161 is in contact with the +Y-side plate surface of the dust-proof glass 311, an increase in the size of the light guide member 161 is suppressed, the effective irradiation portion LAA of the blue light LB is relatively wide, and the peripheral portion LVC of the blue light LB is relatively narrow, and the utilization efficiency of the blue light LB, that is, the amount of light irradiated to the image formation region 355 of the liquid crystal panel 351 and converted into the image light IB with respect to the amount of light of the blue light LB emitted from the light source 121 is improved.

[0086] Returning to FIG. 2, the cooling fan 481 mainly supplies the cold air W toward the extending portion that extends further on the -Z side than the -Z-side end of the light-emitting surface 161b of the light guide member 161 in the dust-proof glass 311. By the extending portion on the -Z side of the dust-proof glass 311 receiving the cold air W from the cooling fan 481, it is cooled from the -Z side to the +Z side, -X side, and +X side. The cold air W from the cooling fan 481 may be directly supplied from the +Y side and the -Z side to the extending portion on the -Z side of the dust-proof glass 311, or may be supplied from the +Y side and the -Z side via a duct or the like (not shown).

[0087] Note that the dust-proof glass 311 extends beyond the light-emitting surface 161b of the light guide member 161 on the +Z side and the ±X sides. The cooling fan 481 may supply cold air W toward an extending portion that extends beyond the light-emitting surface 161b of the dust-proof glass 311 on either the +Z side or the ±X side when viewed along the Y direction. The arrangement of the cooling fan 481 is appropriately determined within a housing (not shown) or an exterior body of the projector 501.

[0088] The blue light LB emitted from the light guide member 161 through the dust-proof glass 311 is converted into image light IB in the image formation region 355 of the liquid crystal panel 351. At this time, heat is generated in the liquid crystal panel 351, and the counter substrate 391 is heated. The counter substrate 391 exchanges heat with the dust-proof glass 311 that is cooled by the cold air W from the cooling fan 481 as described above. The dust-proof glass 311 is cooled from the -Z side end by the cold air W, and is efficiently cooled as a whole toward the +Z side end by heat dissipation. As a result of the heat exchange between the dust-proof glass 311 and the counter substrate 391 of the liquid crystal panel 351, the counter substrate 391 is cooled.

[0089] When the image light IB is generated in the image formation region 355 of the liquid crystal panel 351, the element substrate 393 is further heated compared to the counter substrate 391. The element substrate 393 is cooled by a dedicated cooling fan (not shown) or the like in the same manner as in the prior art. Since the element substrate 393 is cooled and the counter substrate 391 is also cooled as described above, excessive temperature rise and performance degradation of the liquid crystal panel 351 are suppressed, and the conversion efficiency of the blue light LB into the image light IB is improved.

[0090] A part of the cold air W from the cooling fan 481 is supplied to the -Z side surface 161s of the light guide member 161 from the -Z side. As a result, in addition to the dust-proof glass 311, the light guide member 161 is also cooled.

[0091] Although not shown, the green light emitting unit 102 and the red light emitting unit 103 are configured according to the same guidelines as the blue light emitting unit 101 described above. The description of the green light emitting unit 102 is made by replacing, in the description of the blue light emitting unit 101, the light source 121 with the light source 122, the collimating element 131 with the collimating element 132, the condensing element 141 with the condensing element 142, the diffusing device 151A with the diffusing device 151B, the light guiding member 161 with the light guiding member 162, the light emitting surface 161b with the light emitting surface 162b, the blue light LB with the green light LG, the Y direction with the X direction, the XZ plane with the YZ plane, the +Y side with the -X side, and the -Y side with the +X side, respectively.

[0092] The liquid crystal panel 352 is configured according to the same guidelines as the liquid crystal panel 351 described above. The description of the liquid crystal panel 352 is made by replacing, in the description of the liquid crystal panel 351, the dust-proof glass 311 with the dust-proof glass 312, the emitting-side polarizing plate 361 with the emitting-side polarizing plate 362, the Y direction with the X direction, the XZ plane with the YZ plane, the +Y side with the -X side, and the -Y side with the +X side, respectively. Between the dust-proof glass 312 and the emitting-side polarizing plate 362, the counter substrate, the liquid crystal layer, and the element substrate of the liquid crystal panel 352 are sequentially arranged from the -X side to the +X side.

[0093] The description of the red light emitting unit 103 is made by replacing, in the description of the blue light emitting unit 101, the light source 121 with the light source 123, the collimating element 131 with the collimating element 133, the condensing element 141 with the condensing element 143, the diffusing device 151A with the diffusing device 151C, the light guiding member 161 with the light guiding member 163, the light emitting surface 163b with the light emitting surface 163b, the blue light LB with the green light LG, the +Y side with the -Y side, and the -Y side with the +Y side, respectively.

[0094] The liquid crystal panel 353 is configured according to the same guidelines as the liquid crystal panel 351 described above. The description of the liquid crystal panel 353 is made by replacing the dust-proof glass 311 with the dust-proof glass 313, the injection-side polarizing plate 361 with the injection-side polarizing plate 363, the +Y side with the -Y side, and the -Y side with the +Y side in the description of the liquid crystal panel 351. Between the dust-proof glass 313 and the injection-side polarizing plate 363, the counter substrate, the liquid crystal layer, and the element substrate of the liquid crystal panel 353 are sequentially arranged from the -Y side toward the +Y side.

[0095] Returning to FIG. 1, the cooling fan 482 mainly supplies cold air (air) toward an extending portion that extends further to the -Z side than the -Z side end of the light-emitting surface 162b of the light guide member 162 in the dust-proof glass 312. By the extending portion on the -Z side of the dust-proof glass 312 receiving the cold air from the cooling fan 482, the dust-proof glass 312 is cooled. The cold air from the cooling fan 482 may be directly supplied to the extending portion on the -Z side of the dust-proof glass 312 from the -X side and the -Z side, or may be supplied from the -X side and the -Z side via a duct or the like (not shown). Further, the cooling fan 482 may supply cold air toward an extending portion that extends to either the +Z side or the ±X side of the light-emitting surface 162b in the dust-proof glass 312 when viewed along the X direction. The arrangement of the cooling fan 482 is appropriately determined in a housing (not shown) or an exterior body of the projector 501 in the same manner as the cooling fan 481.

[0096] The dust-proof glass 312 is cooled from the -Z side end by the cold air from the cooling fan 482 and is efficiently cooled as a whole toward the +Z side end. Heat exchange occurs between the dust-proof glass 312 and the counter substrate of the liquid crystal panel 352, and the counter substrate of the liquid crystal panel 352 is cooled.

[0097] When the image light IG is generated in the image forming region 356 of the liquid crystal panel 352, the element substrate of the liquid crystal panel 352 is further heated than the counter substrate. The element substrate of the liquid crystal panel 352 is cooled by a dedicated cooling fan or the like (not shown) in the same manner as in the prior art. Since the element substrate and the counter substrate of the liquid crystal panel 352 are cooled, excessive temperature rise and performance degradation of the liquid crystal panel 352 are suppressed, and the conversion efficiency of the green light LG to the image light IG is improved.

[0098] Since part of the cold air from the cooling fan 482 is supplied from the -Z side to the -Z side surface of the light guide member 162, in addition to the dust-proof glass 312, the light guide member 162 is also cooled.

[0099] The cooling fan 483 mainly supplies cold air (air) toward an extension portion that extends further to the -Z side than the -Z side end of the light emitting surface 163b of the light guide member 163 in the dust-proof glass 313. By the extension portion on the -Z side of the dust-proof glass 313 receiving the cold air from the cooling fan 483, the dust-proof glass 313 is cooled. The cold air from the cooling fan 483 may be directly supplied to the extension portion on the -Z side of the dust-proof glass 313 from the -X side and the -Z side, or may be supplied from the -X side and the -Z side via a duct or the like (not shown). Further, the cooling fan 483 may supply cold air toward an extension portion that extends either on the +Z side or the ±X side with respect to the light emitting surface 163b in the dust-proof glass 313 when viewed in the Y direction. The arrangement of the cooling fan 483, similar to the cooling fan 481, is appropriately determined inside or outside a housing (not shown) of the projector 501.

[0100] The dust-proof glass 313 is cooled from the -Z side end by the cold air from the cooling fan 483 and is efficiently cooled overall toward the +Z side end. Heat exchange occurs between the dust-proof glass 313 and the counter substrate of the liquid crystal panel 353, and the counter substrate of the liquid crystal panel 353 is cooled.

[0101] When the image light IG is generated in the image formation region 357 of the liquid crystal panel 353, the element substrate of the liquid crystal panel 353 is further heated than the counter substrate. The element substrate of the liquid crystal panel 353 is cooled by a dedicated cooling fan or the like (not shown) in the same manner as in the prior art. Since the element substrate and the counter substrate of the liquid crystal panel 353 are cooled, excessive temperature rise and performance degradation of the liquid crystal panel 353 are suppressed, and the conversion efficiency of the green light LG into the image light IG is improved.

[0102] Since a part of the cold air from the cooling fan 483 is supplied from the -Z side to the -Z side surface of the light guide member 163, in addition to the dust-proof glass 313, the light guide member 163 is also cooled.

[0103] The projector 501 of the first embodiment described above includes a light source (first light source) 121, a condenser element (first condenser element) 141, a light guide member (first light guide member) 161, and a liquid crystal panel (first liquid crystal panel) 351. The light source 121 emits linearly polarized blue light (first light) LB. The condenser element 141 condenses the blue light LB emitted from the light source 121. The light guide member 161 guides the blue light LB emitted from the condenser element 141. The liquid crystal panel 351 modulates the blue light LB emitted from the light guide member 161 to generate image light IB. The light guide member 161 has an incident surface 161a, an emission surface 161b, and an inclined portion 161t. The blue light LB emitted from the condenser element 141 is incident on the incident surface 161a. The blue light LB is emitted from the emission surface 161b toward the liquid crystal panel 351. The inclined portion 161t has a side surface (inclined surface) 161s that is inclined with respect to the optical axis (first optical axis) AX1 of the light guide member 161. The area (cross-sectional area) of the cross-section intersecting the Y direction parallel to the optical axis AX1 of the inclined portion 161t increases as it proceeds in the -Y side along the Y direction (the direction in which the first light is guided) that guides the blue light LB. In the projector 501 of the first embodiment, the emission surface 161b of the light guide member 161 and a part (a part on the light incident side) of the liquid crystal panel 351 on the incident side of the blue light LB are in contact with each other. For example, a part of the liquid crystal panel 351 on the incident side of the blue light LB is a part of the +Y side plate surface where the blue light LB is incident on the dust-proof glass 311, and is a region (a part) that overlaps the emission surface 161b of the light guide member 161 including the center of the +Y side plate surface of the dust-proof glass 311 when viewed along the Y direction.

[0104] In the projector 501 according to the first embodiment, the blue light LB emitted from the light source 121, the green light LG emitted from the light source 122, and the red light LR emitted from the light source 123 are not synthesized with each other. The blue light LB enters the liquid crystal panel 351 for blue through the optical system including the light guide member 161. The green light LG enters the liquid crystal panel 352 for green through the optical system including the light guide member 162. The red light LR enters the liquid crystal panel 353 for red through the optical system including the light guide member 163.

[0105] In the projector 501 according to the first embodiment, since the emission surface 161b on the -Y side of the light guide member 161 and a part of the plate surface on the +Y side of the dust-proof glass 311 of the liquid crystal panel 351 are in contact with each other, leakage of the blue light LB from the light guide member 161 and the liquid crystal panel 351 to the outside in the Y direction and the XZ plane is suppressed, and the blue light LB emitted from the light guide member 161 efficiently enters the liquid crystal panel 351.

[0106] In the projector 501 according to the first embodiment, the state in which the emission surface 161b of the light guide member 161 and a part of the plate surface on the +Y side of the dust-proof glass 311 are in contact with each other includes a state in which each of the emission surface 161b and the part of the plate surface on the +Y side of the dust-proof glass 311 has the same flatness and the same fine unevenness in the XZ plane, and the entire surfaces of each other are in contact. The state in which the emission surface 161b and a part of the plate surface on the +Y side of the dust-proof glass 311 are in contact with each other includes a state in which one surface of the emission surface 161b and the part of the plate surface on the +Y side of the dust-proof glass 311 has a different flatness from the other surface and different fine unevenness in the XZ plane from the other surface, and there is a variation in the separation distance in the Y direction between the emission surface 161b and the part of the plate surface on the +Y side of the dust-proof glass 311. In this case, the separation distance is, for example, 0 μm or more and 3 μm or less, preferably 1 μm or less.

[0107] According to the projector 501 of the first embodiment, the light utilization efficiency of the blue light LB emitted from the light source 121 can be increased. In the following description, the description of the operation and effect of the blue light emitting unit 101 and the cooling fan 481 of the projector 501 of the first embodiment is also applicable to each of the green light emitting unit 102 and the red light emitting unit 103 configured in the same manner as the blue light emitting unit 101. Therefore, according to the projector 501 of the first embodiment, in addition to the blue light LB emitted from the light source 121, the light utilization efficiency of each of the green light LG emitted from the light source 122 and the red light LR emitted from the light source 123 can be increased.

[0108] In a conventionally known first projector, for example, a light emitting diode (LED) is used as a light source, the parallelism of the light emitted from each of a plurality of LEDs is increased by a tapered rod member (light guide member), and the light emitted from the rod member is polarization-separated by a polarization conversion unit including a polarization beam splitter. The polarization-separated light is synthesized with each other by a photosynthetic member, enters a liquid crystal cell (liquid crystal panel), is converted into image light, and is projected by a projection optical system or the like (for example, Japanese Patent Application Laid-Open No. 2008-083661). In the first projector, the emission surface of the rod member and the incident surface of the cube-shaped polarization beam splitter of the polarization conversion unit are in contact with each other.

[0109] In the conventional first projector, a gap is provided between the emission surface of the polarization beam splitter and the incident surface of the liquid crystal cell. Therefore, in the optical path of the light emitted from the LED, the separation distance between the emission surface of the rod member and the incident surface of the liquid crystal cell is at least the sum of the thickness of the polarization beam splitter and the separation distance between the emission surface of the polarization beam splitter and the incident surface of the liquid crystal cell, and is considerably larger than the thicknesses of components such as a known dust-proof glass, an incident-side polarizing plate, and a counter substrate of the liquid crystal cell. As a result, in the conventional first projector, there is a possibility that light leaks from the gap between the polarization beam splitter and the liquid crystal cell, and the illumination margin for the image formation region of the liquid crystal cell is relatively large.

[0110] In the blue light emitting section 101 of the projector 501 according to the first embodiment, as described above, the emission surface 161b on the -Y side of the light guide member 161 and a part of the plate surface on the +Y side of the dustproof glass 311 of the liquid crystal panel 351 are in contact with each other. Therefore, the separation distance between the emission surface 161b and the liquid crystal layer 392 of the liquid crystal panel 351 in the Y direction can be suppressed to be equivalent to the sum of the thickness of the dustproof glass 311 and the thickness of the counter substrate 391. The illumination margin for the image formation region 355 is relatively small compared to the conventional first projector. Similarly, the illumination margins for the image formation regions 356 of the green light emitting section 102 and 357 of the red light emitting section 102 are relatively small compared to the conventional first projector. According to the projector 501 of the first embodiment, leakage of color light between each of the light guide members 161, 162, 163 and each of the dustproof glasses 311, 312, 313 of the liquid crystal panels 351, 352, 353 is prevented, the illumination margins for each of the image formation regions 355, 356, 357 are suppressed to be small, and the light utilization efficiency of the blue light LB, green light LG, and red light LR can be increased.

[0111] In a conventional second projector, for example, the illuminance distributions of blue light, green light, and red light emitted from a blue LED light source, a green LED light source, and a red LED light source, respectively, are made uniform by individual tapered rod lenses (light guide members). Each color light emitted from the tapered rod lens enters a liquid crystal light valve (liquid crystal panel) through a reflective polarizing element composed of a WGP (Wire Grid Polarizer), is converted into image light, and is projected by a projection optical system or the like (for example, Japanese Patent Application Laid-Open No. 2005-234440). In the second projector, the emission side end surface of the tapered rod lens and the WGP are in contact with each other.

[0112] In the conventional second projector, since light leakage from the gap between the end face and the WGP can be prevented in the direction along the optical path, a decrease in light utilization efficiency due to light leakage from the aforementioned gap can be suppressed. However, since the colored light emitted from the tapered rod lens passes through the WGP, a decrease in light utilization efficiency due to the WGP occurs.

[0113] In the blue light emitting section 101 of the projector 501 according to the first embodiment, as described above, the emission surface 161b on the -Y side of the light guide member 161 and a part of the plate surface on the +Y side of the dust-proof glass 311 of the liquid crystal panel 351 are in contact with each other, and a polarizing plate is not disposed between the light guide member 161 and the +Y side substrate of the liquid crystal panel, that is, the counter substrate 391. According to the projector 501 of the first embodiment, since polarizing plates are not disposed on the incident sides of the liquid crystal panels 351, 352, and 353, a decrease in light utilization efficiency due to light loss caused by absorption and reflection by the polarizing plate does not occur on the incident side of the liquid crystal panel as in the conventional second projector, and the light utilization efficiency of the blue light LB, the green light LG, and the red light LR can be increased.

[0114] The conventional third projector includes, for example, a light source section having an LD light source, a phosphor as a wavelength conversion element that converts the wavelength of the light emitted from the light source section, a light guide (light guide member) that guides the light emitted from the phosphor, a reflective polarizing element that aligns the polarization direction of the light emitted from the light guide, and a reflection mirror disposed so as to surround a portion on the incident side rather than the intermediate position of the light guide. In the conventional third projector, the light emitted from the reflective polarizing element enters the inside of the light guide from the emission surface, propagates toward the incident surface, and contributes to the re-excitation of the phosphor. The emission surface of the light guide is not in contact with the reflective polarizing element and is disposed away from the reflective polarizing element.

[0115] In a conventional third projector, a liquid crystal light valve (liquid crystal panel) is disposed at a distance from a reflective polarizing element on the side opposite to the light guide. Therefore, in the optical path of the light emitted from the light source unit, the separation distance between the light emitting surface of the light guide and the incident surface of the liquid crystal light valve is at least the sum of the separation distance between the light emitting surface of the light guide and the incident surface of the reflective polarizing element, the thickness of the reflective polarizing element, and the separation distance between the light emitting surface of the reflective polarizing element and the incident surface of the liquid crystal light valve, and is considerably larger than the thicknesses of components such as a known dust-proof glass, an incident-side polarizing plate, and a counter substrate of the liquid crystal light valve. As a result, in the conventional third projector, light may leak from the gaps between the light guide and the reflective polarizing element and between the reflective polarizing element and the liquid crystal light valve, and the illumination margin for the image formation regions of the liquid crystal cells is relatively large. Further, in the conventional third projector, since the reflective polarizing element is disposed on the incident side of the liquid crystal light valve and a part of the incident light is reflected by the reflective polarizing element and does not enter the liquid crystal light valve, a reduction in light utilization efficiency occurs.

[0116] According to the projector 501 of the first embodiment, as described above, leakage of color light between each of the light guide members 161, 162, 163 and each of the dust-proof glasses 311, 312, 313 of the liquid crystal panels 351, 352, 353 is prevented, the illumination margin for each of the image formation regions 355, 356, 357 is suppressed to be small, and loss of color light in the polarizing element on the incident side of the liquid crystal panels 351, 352, 353 does not need to be assumed. Therefore, the light utilization efficiency of the blue light LB, the green light LG, and the red light LR can be increased.

[0117] In the projector 501 of the first embodiment, the polarization direction of the linearly polarized blue light LB emitted from the light source 121 is not changed, for example, by a polarizing plate or a polarizing element other than the polarizing plate between the light source 121 and the liquid crystal panel 351, and enters the liquid crystal panel 351 without changing between the light source 121 and the liquid crystal panel 351. That is, the polarization direction of the blue light LB is maintained between the light emitting surface of the light source 121 and the incident surface of the liquid crystal layer 392 of the liquid crystal panel 351.

[0118] According to the projector 501 of the first embodiment, the loss of the light quantity of the blue light LB incident on the liquid crystal layer 392 of the liquid crystal panel 351 can be minimized.

[0119] In the projector 501 of the first embodiment, the shape of the cross section orthogonal to the optical axis AX1 of the light guide member 161 is rectangular. The shape of the light emitting surface 161b of the light guide member 161 is rectangular. The polarization direction of the linearly polarized blue light LB is a direction along one of the X direction (long side direction) and the Z direction (short side direction) in the rectangle of the light emitting surface 161b.

[0120] In the projector 501 of the first embodiment, when the blue light LB is emitted from the light source 121 and enters the light guide member 161, the polarization direction of the blue light LB is along the X direction or the Z direction, which is suitable as the polarization direction of the blue light LB incident on the image forming region 355 of the liquid crystal panel 351. According to the projector 501 of the first embodiment, the loss of the light quantity of the blue light LB until it is guided by the light guide member 161 and enters the liquid crystal layer 392 of the liquid crystal panel 351 is minimized, and the blue light LB can be easily controlled at each pixel of the image forming region 355 of the liquid crystal panel 351 to generate the image light LB.

[0121] In the projector 501 of the first embodiment, the liquid crystal panel 351 has an image forming region 355 in which a plurality of pixels are arranged. The liquid crystal panel 351 includes a counter substrate (first substrate) 391, a liquid crystal layer 392, an element substrate (second substrate) 393, a dustproof glass (incident side dustproof member) 311, and an emission side polarizing plate (emission side dustproof member) 361. The element substrate 393 faces the counter substrate 391 with the liquid crystal layer 392 interposed therebetween. The dustproof glass 311 is disposed on the +Y side (light incident side) with respect to the counter substrate 391. The emission side polarizing plate 361 is disposed on the -Y side (light emission side) with respect to the element substrate 393. In the projector 501 of the first embodiment, the light emitting surface 161b of the light guide member 161 is in contact with the dustproof glass 311.

[0122] In the projector 501 of the first embodiment, specifically, in the XY plane of the dust-proof glass 311 disposed on the most +Y side in the liquid crystal panel 351, the portion overlapping the light-emitting surface 161b of the light guide member 161 when viewed along the Y direction is in contact with the light-emitting surface 161b. According to the projector 501 of the first embodiment, in the Y direction parallel to the optical axis AX1 of the blue light LB, the gap between the light-emitting surface 161b of the light guide member 161 and the incident surface of the liquid crystal layer 392 of the liquid crystal panel 351 can be suppressed to be equal to the sum of the thickness of the dust-proof glass 311 and the thickness of the counter substrate 391. As a result, leakage of color light between the light guide member 161 and the dust-proof glass 311 can be favorably prevented, and the illumination margin for the image formation region 355 can be suppressed to be small.

[0123] The projector 501 of the first embodiment further includes a cooling fan 481 that sends cool air (air) W to the liquid crystal panel 351. In the projector 501 of the first embodiment, the planar size of the dust-proof glass 311 when viewed along the optical axis AX1 of the blue light LB and the Y direction, that is, the size in the XY plane, is larger than the respective planar sizes of the counter substrate 391, the element substrate 393, and the emission-side polarizing plate 361. The cooling fan 481 sends cool air W to the dust-proof glass 311.

[0124] In the projector 501 of the first embodiment, the cool air W from the cooling fan 481 is sent to an extending portion that is larger than the counter substrate 391, the element substrate 393, and the emission-side polarizing plate 361 when viewed along the Y direction in the dust-proof glass 311. By the cool air W from the cooling fan 481, mainly the dust-proof glass 311 is directly cooled, and the light guide member 161 and the counter substrate 391 in contact with the dust-proof glass 311 are indirectly cooled. The element substrate 393 is cooled by the same method as in the prior art. As a result, excessive temperature rise and malfunction of the liquid crystal panel 351 due to irradiation with the blue light LB are prevented. According to the projector 501 of the first embodiment, performance degradation of the liquid crystal panel 351 can be effectively suppressed, and long-term use of the liquid crystal panel 351 is enabled.

[0125] In the projector 501 of the first embodiment, the cooling fan 481 also sends cool air W to the light guide member 161.

[0126] In the projector 501 of the first embodiment, the light guide member 161 is cooled by a part of the cold air W from the cooling fan 481. According to the projector 501 of the first embodiment, heat is received from the dust-proof glass 311 of the liquid crystal panel 351 in contact with the light guide member 161, and heat can be efficiently dissipated from the light guide member 161 having a surface area larger than that of the dust-proof glass 311. Further, according to the projector 501 of the first embodiment, the disturbance of the polarization direction of the blue light LB propagating inside the light guide member 161 can be suppressed.

[0127] The projector 501 of the first embodiment further includes a diffusion device (first diffusion device) 151A. The diffusion device 151A includes a diffusion substrate 152A that diffuses and emits the incident blue light LB, and a drive device 153A that rotates the diffusion substrate 152A. The diffusion device 151A is disposed between the condenser element 141 and the light guide member 161 in the Y direction parallel to the optical axis AX1 of the blue light LB.

[0128] In the projector 501 of the first embodiment, the illuminance distribution of the blue light LB incident on the light guide member 161 in the XZ plane is diffused by the diffusion substrate 152A that rotates in the diffusion device 151A. According to the projector 501 of the first embodiment, the uniformity of the illuminance of the blue light LB incident on the light guide member 161 can be achieved in advance, and the uniformity of the illuminance distribution of the blue light LB emitted from the light emitting surface 161b of the light guide member 161 can be enhanced.

[0129] The projector 501 of the first embodiment further includes a light source (second light source) 122, a condenser element (second condenser element) 142, a light guide member (second light guide member) 162, and a liquid crystal panel (second liquid crystal panel) 352. The light source 122 emits linearly polarized green light (second light) LG having a green wavelength band (second wavelength band) different from the blue wavelength band of the blue light LB. The condenser element 142 condenses the green light LG emitted from the light source 122. The light guide member 162 guides the green light LG emitted from the condenser element 142. The liquid crystal panel 352 modulates the green light LG emitted from the light guide member 162 to generate image light IG. Although not shown, the light guide member 162 has an incident surface parallel to the YZ plane, an emission surface (second emission surface) 162b, and an inclined portion (second inclined portion). The green light LG emitted from the condenser element 142 is incident on the incident surface of the light guide member 162. The green light LG is emitted from the emission surface 162b toward the liquid crystal panel 352. The inclined portion of the light guide member 162 has an inclined surface that is inclined with respect to the optical axis (second optical axis) parallel to the X direction of the light guide member 162 and the XY plane. The cross-sectional area of the second inclined portion in the X direction increases as it advances toward the +X side along the X direction (the direction in which the second light is guided) in which the green light LG is guided. In the projector 501 of the first embodiment, the emission surface 162b of the light guide member 162 and a part (a part on the light incident side) of the liquid crystal panel 352 on the incident side of the green light LG are in contact with each other. For example, a part of the liquid crystal panel 352 on the incident side of the green light LG is a part of the plate surface on the -X side where the green light LG is incident on the dust-proof glass 312, and when viewed along the X direction, it is a region (a part) that overlaps with the emission surface 162b of the light guide member 162 including the center of the plate surface on the -X side of the dust-proof glass 321.

[0130] The projector 501 of the first embodiment further includes a light source 123 that emits red light LR, a condensing element 143, a light guide member 163, and a liquid crystal panel 353. Although not shown, the light guide member 163 has an incident surface parallel to the XZ plane, an emission surface 163b, and an inclined portion. Red light LR emitted from the condensing element 143 is incident on the incident surface of the light guide member 163. Red light LR is emitted from the emission surface 163b toward the liquid crystal panel 353. The inclined portion of the light guide member 163 has an inclined surface that is inclined with respect to the optical axis of the red light LR parallel to the Y direction of the light guide member 163 and the XY plane. The cross-sectional area of the light guide member 163 in the Y direction increases as it advances toward the +Y side along the Y direction in which the red light LR is guided. In the projector 501 of the first embodiment, the emission surface 163b of the light guide member 163 and a part of the incident side of the liquid crystal panel 353 for the red light LR are in contact with each other. For example, a part of the incident side of the liquid crystal panel 353 for the red light LR is a part of the -X side plate surface on which the red light LR is incident on the dust-proof glass 313, and when viewed along the X direction, it is a region that overlaps the emission surface 162b of the light guide member 162 including the center of the -X side plate surface of the dust-proof glass 321.

[0131] In the projector 501 of the first embodiment, since the emission surface 161b on the +X side of the light guide member 162 and a part of the -X side plate surface of the dust-proof glass 312 of the liquid crystal panel 352 are in contact with each other, leakage of the green light LG from the light guide member 162 and the liquid crystal panel 352 to the outside in the X direction and the YZ plane is suppressed, and the green light LG emitted from the light guide member 162 efficiently enters the liquid crystal panel 352. Also, since the emission surface 163b on the +Y side of the light guide member 163 and a part of the -Y side plate surface of the dust-proof glass 313 of the liquid crystal panel 353 are in contact with each other, leakage of the red light LR from the light guide member 163 and the liquid crystal panel 353 to the outside in the Y direction and the XZ plane is suppressed, and the red light LR emitted from the light guide member 163 efficiently enters the liquid crystal panel 353. Therefore, according to the projector 501 of the first embodiment, the light utilization efficiency of the blue light LB emitted from the light source 121, the green light LG emitted from the light source 122, and the red light LR emitted from the light source 123 is increased, and the colored light including the blue light LB, the green light LG, and the red light LR can be brightened.

[0132] (Modification of the First Embodiment) Next, a modification of the first embodiment of the present invention will be described. Although not shown, in a modification of the projector 501 of the first embodiment, in the Y direction, an air layer is provided between the +Y side plate surface of the dust-proof glass 311 of the liquid crystal panel 351 and the -Y side end surface of the light guide member 161 of the blue light emitting unit 101, that is, the light emitting surface 161b. Note that the air layer is not shown in this specification.

[0133] The thickness of the air layer in the Y direction, that is, the separation distance between the light emitting surface 161b and the +Y side plate surface of the dust-proof glass 311, is 3 μm or less, preferably 1 μm or less. The upper limit value of the separation distance of 3 μm is such that the leakage of the blue light LB is suppressed in the same manner as when the light guide member 161 and the dust-proof glass 311 are in contact with each other, that is, when the separation distance is 0 μm, and heat transfer and heat dissipation phenomena occur in the same manner as when the separation distance is 0 μm, and it is a dimension obtained by the intensive study and knowledge of the present inventors using numerical simulations and the like as a separation distance that can be regarded as substantially the same as the state of being in contact with each other.

[0134] The modification of the projector 501 of the first embodiment includes a state in which at least the portions (partial portions) that overlap with each other when viewed along the Y direction on the light emitting surface 161b and the +Y side plate surface of the dust-proof glass 311 have the same flatness as each other, and have the same fine unevenness on the XZ plane, and the entire surfaces of each other are in contact. Similar to the first embodiment, the modification of the projector 501 includes a state in which one surface of the light emitting surface 161b and a partial portion of the +Y side plate surface of the dust-proof glass 311 has a flatness different from that of the other surface, and has fine unevenness on the XZ plane different from that of the other surface, and a variation occurs in the separation distance in the Y direction between the light emitting surface 161b and a partial portion of the +Y side plate surface of the dust-proof glass 311. In this case, the separation distance is, for example, greater than 0 μm and 3 μm or less, preferably 1 μm or less.

[0135] A modified example of the projector 501 according to the first embodiment includes a light source (first light source) 121, a condensing element (first condensing element) 141, a light guide member (first light guide member) 161, and a liquid crystal panel (first liquid crystal panel) 351. In the modified example of the projector 501 according to the first embodiment, an air layer of 3 μm or less is provided between the light emitting surface 161b of the light guide member 161 and a part on the incident side of the blue light LB in the liquid crystal panel 351 (a part on the light incident side).

[0136] In a modified example of the projector 501 according to the first embodiment, since the thickness of the air layer between the light emitting surface 161b of the light guide member 161 and a part of the +Y side plate surface of the dust-proof glass 311 of the liquid crystal panel 351 is 3 μm or less, leakage of the blue light LB from the light guide member 161 and the liquid crystal panel 351 to the outside in the Y direction and the XZ plane is suppressed in substantially the same manner as when the light emitting surface 161b and a part of the +Y side plate surface of the dust-proof glass 311 are in contact with each other. Also, when the image light IB is generated, heat is generated in the liquid crystal panel 351 and the counter substrate 391 is heated. Since the thickness of the air layer between the light emitting surface 161b and a part of the +Y side plate surface of the dust-proof glass 311 is suppressed to 3 μm or less, heat exchange and heat dissipation between the counter substrate 391, the dust-proof glass 311, and the light guide member 141 are performed in substantially the same manner as when the light emitting surface 161b and a part of the +Y side plate surface of the dust-proof glass 311 are in contact with each other, and the dust-proof glass 311 is efficiently cooled as a whole, such as at the -Z side end portion. Further, in the modified example of the projector 501 according to the first embodiment, the illumination margin for each of the image formation regions 355, 356, 357 is preferably suppressed. Also, since polarizing plates are not arranged on the incident sides of the liquid crystal panels 351, 352, 353, respectively, a decrease in light utilization efficiency due to the polarizing plates does not occur on the incident sides of the liquid crystal panels 351, 352, 353, respectively. From these facts, in the modified example of the projector 501 according to the first embodiment, the blue light LB emitted from the light guide member 161 is efficiently incident on the liquid crystal panel 351, the green light LG emitted from the light guide member 162 is efficiently incident on the liquid crystal panel 352, and the red light LR emitted from the light guide member 163 is efficiently incident on the liquid crystal panel 353. According to the modified example of the projector 501 according to the first embodiment, the light utilization efficiency of each of the blue light LB, the green light LG, and the red light LR can be increased.

[0137] According to the modified example of the projector 501 according to the first embodiment, the operational effects achieved by the configuration common to the projector 501 can be obtained.

[0138] (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. 6. In the description of the second embodiment and its modification, the content common to the first embodiment and its modification is omitted, and the same reference numerals as the corresponding components in the projector 501 of the first embodiment are used for the components common to the projector 501 of the first embodiment. In the description of the second embodiment and its modification, only the components and content different from those already described in the first embodiment and its modification are described.

[0139] Although not shown, the projector of the second embodiment of the present invention includes, similarly to the projector 501 of the first embodiment, a blue light emitting unit 101, a green light emitting unit 102, a red light emitting unit 103, a liquid crystal panel 371 for blue light LB, a liquid crystal panel for green light LG, a liquid crystal panel for red light LR, a light synthesizing member 200, a projection optical system 450, and cooling fans 481, 482, 483.

[0140] FIG. 6 is an enlarged view of a part of the projector of the second embodiment, and is a schematic view when the blue light emitting unit 101 and the liquid crystal panel 371 are viewed from the +X side to the -X side along the X direction. In FIG. 2, the substrate 111 is omitted.

[0141] As shown in FIG. 6, the liquid crystal panel 371 in the second embodiment is obtained by deleting the dust-proof glass 311 of the liquid crystal panel 351 for blue light LB in the projector 501 of the first embodiment and expanding the counter substrate 391 in the X direction and the Z direction, and includes a counter substrate 491, a liquid crystal layer 392, an element substrate 393, and an emission-side polarizing plate 361, which are sequentially stacked and arranged from the +Y side to the -Y side in the Y direction.

[0142] In the second embodiment, the counter substrate 491 is disposed at a position overlapping the light guide member 161 in the X direction and the Z direction, and is disposed on the most +Y side in the liquid crystal panel 371. The plate surface on the +Y side of the counter substrate 491 is in contact with the end surface on the -Y side of the light guide member 161, that is, the light emitting surface 161b. The counter substrate 491 prevents a substance that blocks the propagation of the blue light LB such as dust from entering the pixel constituent portion of the liquid crystal panel 371 from the +Y side. The base substrate of the counter substrate 491 is formed of a material that transmits light in at least the blue wavelength band of the visible wavelength band, and is preferably formed of a material having excellent heat dissipation properties. The material of the counter substrate 491 is, for example, quartz, optical glass, etc., and is preferably sapphire having excellent light transmittance and heat dissipation properties.

[0143] The counter substrate 491 corresponds to the first substrate. The plate surface of the counter substrate 491 is clearly larger than the light emitting surface 161b of the light guide member 161 in the X direction and the Z direction, has the same size as the plate surface of the dustproof glass 311 in the first embodiment, and is at least larger than the image forming region 355. The center of the plate surface of the counter substrate 491 overlaps the optical axis AX1 of the blue light LB.

[0144] The counter substrate 491 extends beyond the light emitting surface 161b of the light guide member 161 in the ±Z side and the ±X side. The cooling fan 481 supplies the cold air W toward the extending portion that extends beyond the light emitting surface 161b in the -Z side when viewed along the Y direction in the counter substrate 491 when viewed along the Y direction. Note that the cooling fan 481 may supply the cold air W toward the extending portion that extends beyond the light emitting surface 161b in either the +Z side or the ±X side when viewed along the Y direction in the counter substrate 491.

[0145] The blue light LB emitted from the light guide member 161 passes through the counter substrate 491 of the liquid crystal panel 371 and is converted into image light IB in the liquid crystal layer 392 of the image forming region 355. At this time, the counter substrate 391 is heated from the -Y side, but is cooled from the +Y side and the -Z side by the cold air W from the cooling fan 481, and is efficiently cooled as a whole toward the end on the +Z side by heat exchange and heat dissipation. Since the element substrate 393 and the counter substrate 491 are cooled, excessive temperature rise and performance degradation of the liquid crystal panel 371 are suppressed, and the conversion efficiency of the blue light LB into the image light IB is improved.

[0146] The illumination margin in the blue light emitting unit 101 of the second embodiment is suppressed by the size of the counter substrate 391 in the Y direction, that is, the thickness of the counter substrate 391.

[0147] Although not shown, in the projector of the second embodiment, a single dust-proof glass is not arranged on the liquid crystal panel for the green light LG, and the plate surface on the -X side of the counter substrate is in contact with the light emitting surface 162b of the light guide member 162. The counter substrate of the liquid crystal panel for the green light LG has an extending portion that extends more than the light emitting surface 162b to the ±Y side and the ±Z side when viewed along the X direction. The cooling fan 482 sends cold air to the counter substrate of the liquid crystal panel for the green light LG and the light guide member 162.

[0148] In the projector of the second embodiment, a single dust-proof glass is not arranged on the liquid crystal panel for the red light LR, and the plate surface on the -Y side of the counter substrate is in contact with the light emitting surface 163b of the light guide member 163. The counter substrate of the liquid crystal panel for the red light LR has an extending portion that extends more than the light emitting surface 163b to the ±X side and the ±Z side when viewed along the Y direction. The cooling fan 483 sends cold air to the counter substrate of the liquid crystal panel for the red light LR and the light guide member 163.

[0149] The projector according to the second embodiment described above includes a light source (first light source) 121, a condenser element (first condenser element) 141, a light guide member (first light guide member) 161, and a liquid crystal panel (first liquid crystal panel) 371. The liquid crystal panel 371 modulates the blue light LB emitted from the light guide member 161 to generate image light IB. In the projector of the second embodiment, the light emitting surface 161b of the light guide member 161 and a part of the liquid crystal panel 371 on the incident side of the blue light LB (a part on the light incident side) are in contact with each other. For example, a part of the liquid crystal panel 371 on the incident side of the blue light LB is a part of the +Y side plate surface on which the blue light LB is incident on the counter substrate 491, and when viewed along the Y direction, it is a region (a part) that overlaps the light emitting surface 161b of the light guide member 161 including the center of the +Y side plate surface of the counter substrate 491.

[0150] In the projector of the second embodiment, since the light emitting surface 161b of the light guide member 161 and a part of the +Y side plate surface of the counter substrate 491 of the liquid crystal panel 371 are in contact with each other, leakage of the blue light LB from the light guide member 161 and the liquid crystal panel 371 to the outside in the Y direction and the XZ plane is suppressed. Also, in the projector of the second embodiment, the illumination margin for the image formation regions 355, 356, 357 is well suppressed. Furthermore, since polarizing plates are not arranged on the incident sides of the liquid crystal panels 351, 352, 353, a decrease in light utilization efficiency due to the polarizing plates does not occur on the incident sides of the liquid crystal panels 351, 352, 353. From these facts, in the projector of the second embodiment, the blue light LB emitted from the light guide member 161 efficiently enters the liquid crystal panel 371, the green light LG emitted from the light guide member 162 efficiently enters the liquid crystal panel 372, and the red light LG emitted from the light guide member 163 efficiently enters the liquid crystal panel 373. According to the projector 501 of the second embodiment, the light utilization efficiency of each of the blue light LB, the green light LG, and the red light LR can be increased.

[0151] In the projector of the second embodiment, the operational effects achieved by the configuration common to the projector 501 of the first embodiment can be obtained.

[0152] In the projector according to the second embodiment, the liquid crystal panel 371 has an image forming region 355 in which a plurality of pixels are arranged. The liquid crystal panel 371 includes a counter substrate (first substrate) 491, a liquid crystal layer 392, an element substrate (second substrate) 393, and an emission-side polarizing plate (emission-side dustproof member) 361. In the projector according to the second embodiment, the light emitting surface 161b of the light guide member 161 is in contact with the counter substrate 491.

[0153] In the projector according to the second embodiment, in the XY plane of the counter substrate 491 that is arranged on the most +Y side in the liquid crystal panel 351, when viewed along the Y direction, the portion that overlaps with the light emitting surface 161b of the light guide member 161 is in contact with the light emitting surface 161. According to the projector of the second embodiment, in the Y direction, the gap between the light emitting surface 161b of the light guide member 161 and the incident surface of the liquid crystal layer 392 of the liquid crystal panel 351 can be suppressed to be equal to the thickness of the counter substrate 391. As a result, the leakage of color light between the light guide member 161 and the counter substrate 491 can be prevented well, and the illumination margin for the image forming region 355 can be suppressed to be small.

[0154] The projector according to the second embodiment further includes a cooling fan 481 that sends cold air (air) W to the liquid crystal panel 351. In the projector according to the second embodiment, the optical axis AX1 of the blue light LB and the planar size of the counter substrate 491 when viewed along the Y direction, that is, the size in the XY plane, are larger than the respective planar sizes of the element substrate 393 and the emission-side polarizing plate 361. The cooling fan 481 sends cold air W to the counter substrate 491.

[0155] In the projector of the second embodiment, the cold air W from the cooling fan 481 is sent to the element substrate 393 and the extending portion protruding from the injection-side polarizing plate 361 when viewed along the Y direction on the opposing substrate 491. By the cold air W from the cooling fan 481, mainly the opposing substrate 491 is directly cooled, and the light guide member 161 in contact with the opposing substrate 491 is indirectly cooled. The element substrate 393 is cooled by the same method as in the prior art. As a result, the performance degradation of the liquid crystal panel 351 due to the irradiation of the blue light LB is suppressed. According to the projector of the second embodiment, the performance degradation of the liquid crystal panel 351 is effectively suppressed, enabling the long-term use of the liquid crystal panel 351.

[0156] In the projector of the second embodiment, the cooling fan 481 also sends the cold air W to the light guide member 161.

[0157] In the projector of the second embodiment, the light guide member 161 is cooled by a part of the cold air W from the cooling fan 481. According to the projector of the second embodiment, the disturbance of the polarization direction of the blue light LB propagating inside the light guide member 161 can be suppressed. According to the projector of the second embodiment, heat can be efficiently dissipated from the light guide member 161, which has a larger surface area than the dust-proof glass 311, and receives heat from the dust-proof glass 311 of the liquid crystal panel 351 in contact with the light guide member 161.

[0158] (Modification of the Second Embodiment) Next, a modification of the second embodiment of the present invention will be described. Although not shown, in a modification of the projector of the second embodiment, an air layer is provided between the +Y-side plate surface of the opposing substrate 491 of the liquid crystal panel 371 and the -Y-side end surface of the light guide member 161 of the blue light emitting portion 101, that is, the light emitting surface 161b in the Y direction. The thickness of the air layer in the Y direction, that is, the separation distance between the light emitting surface 161b and the +Y-side plate surface of the opposing substrate 491, is 3 μm or less, preferably 1 μm or less.

[0159] In the modified example of the projector according to the second embodiment, each of the part (a part) overlapping the emission surface 161b at least in the Y direction on the +Y side plate surface of the emission surface 161b and the opposing substrate 491 has the same flatness as each other, and has the same fine unevenness in the XZ plane, and a state where the entire surfaces of each other are in contact is included. In the modified example of the projector according to the second embodiment, one of the emission surface 161b and a part of the +Y side plate surface of the opposing substrate 491 has a flatness different from that of the other surface, and has fine unevenness in the XZ plane different from that of the other surface, and a state where there is a variation in the separation distance in the Y direction between the emission surface 161b and a part of the +Y side plate surface of the opposing substrate 491 is also included. The separation distance in this case is, for example, greater than 0 μm and 3 μm or less, preferably 1 μm or less.

[0160] The modified example of the projector according to the second embodiment includes a light source (first light source) 121, a condensing element (first condensing element) 141, a light guide member (first light guide member) 161, and a liquid crystal panel (first liquid crystal panel) 371. In the modified example of the projector according to the second embodiment, an air layer of 3 μm or less is provided between the emission surface 161b of the light guide member 161 and a part on the incident side of the blue light LB in the liquid crystal panel 371 (a part on the light incident side).

[0161] In a modified example of the projector according to the second embodiment, since the thickness of the air layer between the light-emitting surface 161b of the light guide member 161 and a part of the +Y side plate surface of the counter substrate 491 of the liquid crystal panel 371 is 3 μm or less, leakage of the blue light LB from the light guide member 161 and the liquid crystal panel 351 to the outside in the Y direction and the XZ plane can be suppressed in substantially the same manner as in the state where the light-emitting surface 161b and a part of the +Y side plate surface of the counter substrate 491 are in contact with each other. Also, when the image light IB is generated, heat is generated in the liquid crystal panel 371 and the counter substrate 491 is heated. Since the thickness of the air layer between the light-emitting surface 161b and a part of the +Y side plate surface of the counter substrate 491 is suppressed to 3 μm or less, heat exchange and heat dissipation between the counter substrate 491 and the light guide member 141 are performed in substantially the same manner as in the state where the light-emitting surface 161b and a part of the +Y side plate surface of the counter substrate 491 are in contact with each other, and the counter substrate 491 is efficiently cooled as a whole, such as at the -Z side end portion. Further, in the modified example of the projector according to the second embodiment, the illumination margins for the respective image formation regions 355, 356, 357 are favorably suppressed. Also, since polarizing plates are not arranged on the incident sides of the respective liquid crystal panels 351, 352, 353, a decrease in light utilization efficiency due to the polarizing plates does not occur on the incident sides of the respective liquid crystal panels 351, 352, 353. From these facts, in the modified example of the projector according to the second embodiment, the blue light LB emitted from the light guide member 161 efficiently enters the liquid crystal panel 351, the green light LG emitted from the light guide member 162 efficiently enters the liquid crystal panel 352, and the red light LR emitted from the light guide member 163 efficiently enters the liquid crystal panel 353. According to the modified example of the projector according to the second embodiment, the light utilization efficiency of each of the blue light LB, the green light LG, and the red light LR can be increased.

[0162] According to a modified example of the projector according to the second embodiment, the operational effects achieved by the configuration common to the projector according to the second embodiment can be obtained.

[0163] As described above, the preferred embodiments of the present invention have been described in detail. However, the present invention is not limited to such specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

[0164] For example, in the above-described embodiment, a three-panel projector using three-color lights of blue light LB, green light LG, and red light LR is exemplified. However, the projector of the present invention may be, for example, a single-panel projector using one-color light of linearly polarized light, or a projector using four or more colors of linearly polarized light and capable of synthesizing a plurality of color lights with each other by a plurality of photosynthetic members.

[0165] [Summary of the present disclosure] Hereinafter, a summary of the present disclosure will be appended. (Appendix 1) A projector comprising: a first light source that emits a first light of linearly polarized light; a first condenser element that condenses the first light emitted from the first light source; a first light guide member that guides the first light emitted from the first condenser element; and a first liquid crystal panel that modulates the first light emitted from the first light guide member, wherein the first light guide member has a first incident surface on which the first light emitted from the first condenser element is incident, a first emission surface that emits the first light toward the first liquid crystal panel, and a first inclined portion that is inclined with respect to a first optical axis of the first light guide member and has a cross-sectional area that increases in a direction of guiding the first light, and the first emission surface of the first light guide member is in contact with a part of the light incident side of the first liquid crystal panel, or an air layer of 3 μm or less is provided between the first emission surface and the part.

[0166] According to the configuration of Appendix 1, leakage between the first light guide member and the first liquid crystal panel of the first light emitted from the first light source is suppressed, the illumination margin with respect to the image formation region of the first liquid crystal panel is suppressed, and the loss of the first light due to the polarizing plate on the incident side of the first liquid crystal panel does not need to be considered, so that the light utilization efficiency of the first light can be increased.

[0167] (Appendix 2) The projector according to Appendix 1, wherein the linearly polarized first light emitted from the first light source is incident on the first liquid crystal panel without a change in the polarization direction between the first light source and the first liquid crystal panel.

[0168] According to the configuration of Supplementary Note 2, since the fluctuation of the polarization direction of the first light until it enters the first liquid crystal panel and the rotation of the polarization direction with respect to the first optical axis in the plane orthogonal to the first optical axis are suppressed, the loss of the light amount of the first light incident on the first liquid crystal panel can be minimized.

[0169] (Supplementary Note 3) The shape of the cross-section of the first light guide member orthogonal to the first optical axis is rectangular, the shape of the first light emitting surface is rectangular, and the polarization direction of the first light of linearly polarized light is a direction along one of the long side direction and the short side direction in the rectangle, the projector according to Supplementary Note 1 or Supplementary Note 2.

[0170] According to the configuration of Supplementary Note 3, when the first light enters the first light guide member, since the polarization direction of the first light is along a direction suitable as the polarization direction incident on a plurality of pixels of the first liquid crystal panel, the loss of the light amount of the first light guided by the first light guide member until it enters the first liquid crystal panel can be minimized, and the first light can be easily controlled by each pixel of the first liquid crystal panel to generate image light.

[0171] (Supplementary Note 4) The first liquid crystal panel has an image forming region in which a plurality of pixels are arranged, the first liquid crystal panel includes a first substrate, a second substrate facing the first substrate via a liquid crystal layer, an incident side dustproof member disposed on the light incident side with respect to the first substrate, and an emission side dustproof member disposed on the light emission side with respect to the second substrate, and the first light emitting surface is in contact with the incident side dustproof member, or an air layer is provided between the first light emitting surface and the incident side dustproof member, the projector according to any one of Supplementary Notes 1 to 3.

[0172] According to the configuration of Supplementary Note 4, the separation distance between the first light guide member and the liquid crystal layer of the first liquid crystal panel can be suppressed to be equal to the sum of the thickness of the incident side dustproof member and the first substrate, the leakage of the first light between the first light guide member and the incident side dustproof member can be well prevented, the illumination margin with respect to the image forming region of the first liquid crystal panel can be suppressed to be small, and the light utilization efficiency of the first light can be increased.

[0173] (Appendix 5) The projector according to Appendix 4 further includes a cooling fan that sends air to the first liquid crystal panel, and the planar size of the incident-side dust-proof member when viewed along the first optical axis is larger than the planar sizes of the first substrate, the second substrate, and the emission-side dust-proof member, and the cooling fan sends the air to the incident-side dust-proof member.

[0174] According to the configuration of Appendix 5, the incident-side dust-proof member of the first liquid crystal panel to which air is supplied from the cooling fan is cooled, and excessive temperature rise and malfunction of the first liquid crystal panel due to irradiation with the first light are prevented. Therefore, the performance degradation of the first liquid crystal panel can be effectively suppressed, and long-term use of the first liquid crystal panel can be enabled.

[0175] (Appendix 6) The projector according to Appendix 5, wherein the cooling fan also sends the air to the first light guide member.

[0176] According to the configuration of Appendix 6, since the first light guide member having a surface area larger than that of the incident-side dust-proof member of the first liquid crystal panel is cooled by a part of the air supplied from the cooling fan, the heat transmitted from the first liquid crystal panel can be efficiently dissipated.

[0177] (Appendix 7) The first liquid crystal panel has an image formation region in which a plurality of pixels are arranged, and the first liquid crystal panel includes a first substrate, a second substrate facing the first substrate via a liquid crystal layer, and an emission-side dust-proof member disposed on the light emission side with respect to the second substrate, and the first emission surface is in contact with the first substrate or an air layer is provided between the first emission surface and the first substrate. The projector according to any one of Appendix 1 to Appendix 3.

[0178] According to the configuration of Appendix 7, the separation distance between the first light guide member and the liquid crystal layer of the first liquid crystal panel can be suppressed to be equivalent to the thickness of the first substrate, the leakage of the first light between the first light guide member and the incident-side dust-proof member can be well prevented, the illumination margin for the image formation region of the first liquid crystal panel can be suppressed to be small, and the light utilization efficiency of the first light can be increased.

[0179] (Supplementary Note 8) The projector according to Supplementary Note 7 further includes a cooling fan that sends air to the first liquid crystal panel, and the planar size of the first substrate when viewed along the first optical axis is larger than the planar sizes of the second substrate and the injection-side dust-proof member, and the cooling fan sends the air to the first substrate.

[0180] According to the configuration of Supplementary Note 8, the first substrate of the first liquid crystal panel to which air is supplied from the cooling fan is cooled, and excessive temperature rise and malfunction of the first liquid crystal panel due to irradiation with the first light are prevented. Therefore, deterioration of the performance of the first liquid crystal panel can be effectively suppressed, and long-term use of the first liquid crystal panel can be enabled.

[0181] (Supplementary Note 9) The projector according to Supplementary Note 8, wherein the cooling fan also sends the air to the first light guide member.

[0182] According to the configuration of Supplementary Note 9, since the first light guide member having a surface area larger than that of the first substrate of the first liquid crystal panel is cooled by a part of the air supplied from the cooling fan, heat transmitted from the first liquid crystal panel can be efficiently dissipated.

[0183] (Supplementary Note 10) The projector according to any one of Supplementary Notes 1 to 9 further includes a first diffusion device having a first diffusion substrate that diffuses and emits the incident first light and a first driving device that rotates the first diffusion substrate, and the first diffusion device is disposed between the first condenser element and the first light guide member.

[0184] According to the configuration of Supplementary Note 10, since the illuminance distribution of the first light incident on the first light guide member is diffused by the diffusion substrate of the first diffusion device, the uniformity of the illuminance distribution of the first light emitted from the first light guide member can be enhanced.

[0185] (Appendix 11) A second light source that emits second light that is linearly polarized and has a second wavelength band different from the first wavelength band of the first light, a second condenser element that condenses the second light emitted from the second light source, a second light guide member that guides the second light emitted from the second condenser element, a second liquid crystal panel that modulates the second light emitted from the second light guide member, and a light combining member that combines the first light and the second light to emit combined light. The second light guide member has a second incident surface on which the second light emitted from the second condenser element is incident, a second emission surface that emits the second light toward the second liquid crystal panel, and a second inclined portion that is inclined with respect to the second optical axis of the second light guide member and has a cross-sectional area that increases in the direction of guiding the second light. The second emission surface of the second light guide member is in contact with a part of the light incident side of the second liquid crystal panel, or an air layer of 3 μm or less is provided between the second emission surface and the part. The projector according to any one of Appendices 1 to 10.

[0186] According to the configuration of Appendix 11, the light utilization efficiency of each of the first light emitted from the first light source 121 and the second light emitted from the second light source can be increased, and the color light including the first light and the second light projected from the projector can be brightened.

Description of Reference Numerals

[0187] 121... Light source (first light source), 122... Light source (second light source), 141... Condenser element (first condenser element), 142... Condenser element (second condenser element), 161... Light guide member (first light guide member), 162... Light guide member (second light guide member), 351... Liquid crystal panel (first liquid crystal panel), 352... Liquid crystal panel (second liquid crystal panel), 501... Projector.

Claims

1. A first light source that emits a first linearly polarized light, A first condenser element that condenses the first light emitted from the first light source, A first light guide member that guides the first light emitted from the first condenser element, A first liquid crystal panel that modulates the first light emitted from the first light guide member, Comprising, The first light guide member, A first incident surface on which the first light emitted from the first condenser element is incident, A first emission surface that emits the first light toward the first liquid crystal panel, A first inclined portion that is inclined with respect to the first optical axis of the first light guide member and has a cross-sectional area that increases in accordance with the direction in which the first light is guided, Having, The first emission surface of the first light guide member is in contact with a part of the light incident side of the first liquid crystal panel, or an air layer of 3 μm or less is provided between the first emission surface and the part, A projector.

2. The first linearly polarized light emitted from the first light source is incident on the first liquid crystal panel without a change in the polarization direction between the first light source and the first liquid crystal panel, The projector according to claim 1.

3. The shape of a cross section orthogonal to the first optical axis of the first light guide member is rectangular, The shape of the first emission surface is rectangular, The polarization direction of the first linearly polarized light is a direction along one of the long side direction and the short side direction in the rectangle, The projector according to claim 1 or claim 2.

4. The first liquid crystal panel has an image formation region in which a plurality of pixels are arranged, The first liquid crystal panel, A first substrate, A second substrate facing the first substrate via a liquid crystal layer, An incident side dustproof member disposed on the light incident side with respect to the first substrate, An emission side dustproof member disposed on the light emission side with respect to the second substrate, Comprising, The first emission surface is in contact with the incident side dustproof member, or the air layer is provided between the first emission surface and the incident side dustproof member, The projector according to claim 1 or claim 2.

5. Further comprising a cooling fan that sends air to the first liquid crystal panel, The planar size of the incident side dustproof member when viewed along the first optical axis is larger than the planar sizes of the first substrate, the second substrate, and the emission side dustproof member, The cooling fan sends the air to the incident side dustproof member, The projector according to claim 4.

6. The cooling fan also sends the air to the first light guide member, The projector according to claim 5.

7. The first liquid crystal panel has an image formation region in which a plurality of pixels are arranged, The first liquid crystal panel, A first substrate, A second substrate facing the first substrate via a liquid crystal layer, An emission-side dustproof member disposed on the light emission side with respect to the second substrate, And comprising, The first emission surface is in contact with the first substrate, or an air layer is provided between the first emission surface and the first substrate, The projector according to claim 1 or claim 2.

8. The projector further includes a cooling fan that sends air to the first liquid crystal panel, When viewed along the first optical axis, the planar size of the first substrate is larger than the planar sizes of the second substrate and the emission-side dustproof member, The cooling fan sends the air to the first substrate, The projector according to claim 7.

9. The cooling fan also sends the air to the first light guide member, The projector according to claim 8.

10. The projector further includes a first diffusion device having a first diffusion substrate that diffuses and emits the incident first light and a first driving device that rotates the first diffusion substrate, The first diffusion device is disposed between the first condenser element and the first light guide member, The projector according to claim 1 or claim 2.

11. A second light source that emits second light that is linearly polarized and has a second wavelength band different from the first wavelength band of the first light, A second condenser element that condenses the second light emitted from the second light source, A second light guide member that guides the second light emitted from the second condenser element, A second liquid crystal panel that modulates the second light emitted from the second light guide member, And a light combining member that combines the first light and the second light to emit combined light, And further comprising, The second light guide member, A second incident surface on which the second light emitted from the second condenser element is incident, A second emission surface that emits the second light toward the second liquid crystal panel, A second inclined portion that is inclined with respect to the second optical axis of the second light guide member and has an increasing cross-sectional area in the direction of guiding the second light, And having, The second emission surface of the second light guide member is in contact with a part of the light incident side of the second liquid crystal panel, or an air layer of 3 μm or less is provided between the second emission surface and the part, The projector according to claim 1 or claim 2.

Images