Projector

Abstract

Provided is a projector that suppresses a decrease in light utilization efficiency in the projector. The projector includes: a first light source that emits linearly polarized first light; a first light-condensing 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 light collecting 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 light collecting element is incident; a first emission surface that emits 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 that has a cross-sectional area that increases in a direction in which the first light is guided. The first emission surface of the first light guide member is in contact with a portion of the first liquid crystal panel on the light incident side, or an air layer of 3 [mu] m or less is provided between the first emission surface and the portion of the first liquid crystal panel on the light incident side.

Description

Technical Field

[0001] The present invention relates to a projector. Background Art

[0002] Conventionally, a projector having a light modulation device that generates image light of each of the three primary colors using three liquid crystal panels, that is, a three-panel type projector, has been known. For example, a three-panel type projector is disclosed in Patent Document 1. 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.

[0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2010-276757

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

[0005] A projector according to one aspect of the present invention includes: a first light source that emits linearly polarized first 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 into 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 a cross-sectional area of the first inclined portion increases as it faces the direction in which the first light is guided. 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. Brief Description of the Drawings

[0006] Figure 1 is a schematic diagram of a projector according to the first embodiment.

[0007] Figure 2 is Figure 1 a schematic diagram of a blue light emission unit and a blue liquid crystal panel of the projector.

[0008] Figure 3Yes Figure 1 A perspective view of a light guide member of a blue light emitting portion of a projector.

[0009] Figure 4 It shows the result of calculating the illuminance distribution of the blue light emitted from the Figure 1 blue light emitting portion of the projector by numerical simulation.

[0010] Figure 5 It is an image showing the result of calculating the illuminance distribution of the blue light emitted from the blue light emitting portion of a conventional projector by numerical simulation.

[0011] Figure 6 It is a schematic diagram of the blue light emitting portion and the blue liquid crystal panel of the projector according to the second embodiment.

[0012] Reference numeral description

[0013] 121: Light source (first light source); 122: Light source (second light source); 141: Condensing element (first condensing element); 142: Condensing element (second condensing 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. Detailed embodiments

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, in order to easily observe each component, the scale of the dimensions may be changed according to the component.

[0015] First embodiment

[0016] First, refer to Figures 1 to 5 to describe the first embodiment of the present invention. Figure 1 It 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 having three liquid crystal panels as a light modulation device, and is a so-called three-panel projector. As Figure 1 shown, the projector 501 includes a blue light emitting portion 101, a green light emitting portion 102, a red light emitting portion 103, liquid crystal panels 351, 352, 353, a light combining member 200, a projection optical system 450, and cooling fans 481, 482, 483.

[0017] The blue light emitting unit 101 emits blue light LB. In the following description, the 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. One direction orthogonal to the Y direction in the plane containing 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. The 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 along the Y direction from the +Y side to the -Y side.

[0018] The blue light emitting unit 101 includes a light source 121, a collimating element 131, a condensing element 141, a diffusion device 151A, and a light guiding member 161. The blue light emitting unit 101 has, 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 the ratio of the required light amount of the blue light LB emitted from the blue light emitting unit 101 toward the photosynthesis member 200 to the light amount of the blue light LB emitted from one light source 121, etc.

[0019] The light source 121 is supported by a substrate 111. The light source 121 is disposed on the -Y side plate surface in the plate surface parallel to the XZ plane including the X direction and the Z direction in the substrate 111, and is arranged at intervals in the X direction, for example. The substrate 111 is formed of, for example, metal, alloy, etc., but may also be formed of an insulator such as resin. Metal wirings and electrodes (not shown) are disposed on the -Y side plate surface of the substrate 111. The metal wirings and electrodes provided on the substrate 111 are connected to the light source 121.

[0020] The light emitting surface of the light source 121 is arranged substantially parallel to the XZ plane, and is the surface on the side opposite to the surface in contact with the -Y side plate surface of the substrate 111 in the light source 121 in the Y direction. 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 light. The blue light LB corresponds to the first light. The polarization direction of the blue light LB is along any one direction, for example, parallel to 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, diverges at an angle corresponding to the size of the light emitting surface and the peak wavelength of the blue light LB, etc., with the axis passing through the center of the light emitting surface of the light source 121 and parallel to the Y direction as the center, and travels toward the -Y side. The blue wavelength band is, for example, a band of 420 nm to 500 nm.

[0021] The light source 121 is constituted by, for example, a laser diode (LD) that emits blue light LB. In addition, when there are a plurality of light sources 121 in the blue light emitting unit 101, 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 surface of the substrate 111, or may be arranged at intervals only in the Z direction.

[0022] The blue light emitting unit 101 has the same number of collimating elements 131 as the light sources 121. One collimating element 131 among the plurality of collimating elements 131 is arranged corresponding to one light source 121 among 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 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 at a position closer to the -Y side than the light source 121. The incident surface of the collimating element 131 faces the emission surface of the light source 121. The collimating element 131 collimates the blue light LB emitted from the light source 121 in a state of radially diverging around the optical axis parallel to the Y direction, and emits the collimated blue light LB along the Y direction to the -Y side.

[0023] 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 at a position closer to the -Y side than the collimating element 131. The condensing element 141 corresponds to the first condensing element. The condensing element 141 collects the light beams of the plurality of blue light LBs emitted along the Y direction from the collimating element 131, emits them along the Y direction to the -Y side, 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 also be an optical element other than a plano-convex lens such as a biconvex lens that can condense the incident blue light LB as described above.

[0024] 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 circular when viewed along the Y direction, and has an appropriate thickness in the Y direction. The center in the XZ plane of the diffusion substrate 152A is deviated from the optical axis of the blue light LB emitted from the condensing element 141, and is arranged, for example, at a position closer to the -X side than the optical axis of the blue light LB, and is arranged at a position substantially the same as the optical axis of the blue light LB in the Z direction. The optical axis of the blue light LB emitted from the condensing element 141 intersects between a specified position moved outward from the center in the radial direction with respect to the center in the XZ plane of the diffusion substrate 152A and the outer peripheral end. The above-mentioned specified position corresponds to a position overlapping the outer edge of the driving device 153A in the radial direction with respect to the center in the XZ plane of the diffusion substrate 152A when viewed along the Y direction.

[0025] On the diffusion surface of the diffusion device 151A, a fine concavo-convex structure designed according to the peak wavelength of the incident color light, etc., is formed. The concavo-convex structure can be constituted by, for example, a microlens array composed of a plurality of microlenses, or can be formed by sandblasting. The shape of the concavo-convexities is not particularly limited as long as it can diffuse the incident blue light LB in the XZ plane.

[0026] The driving device 153A is arranged at a position on the -X side of the optical path of the blue light LB emitted from the condensing element 141, at a position on the +Y side of the diffusion substrate 152A, and is arranged in the Z direction within a range overlapping the optical path of the blue light LB. The driving device 153A is coaxially connected to the diffusion substrate 152A 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 centered on the rotation axis of the diffusion substrate 152A. The blue light LB incident 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 diffuses 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.

[0027] The light guide member 161 is arranged on the optical path of the blue light LB emitted from the diffusion substrate 152A of the diffusion device 151A, at a position on the -Y side of the diffusion substrate 152A. The light guide member 161 is formed in a long strip shape along the Y direction. The central axis of the light guide member 161 on 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 is incident on the liquid crystal panel 351 for blue via the dust-proof glass 311. The detailed structure of the light guide member 161 will be described later.

[0028] 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 direction parallel to the long side of the image forming region 355 of the liquid crystal panel 351 described later, or parallel to the Z direction, that is, the direction parallel to the short side of the image forming region 355 of the liquid crystal panel 351. In the optical path of the blue light LB, polarization maintaining type elements or components are respectively applied to the collimating element 131, the condensing element 141, the diffusion substrate 152A of the diffusion device 151A, and the light guide member 161 disposed at a position subsequent to the light source 121. The collimating element 131, the condensing element 141, the diffusion substrate 152A, and the light guide member 161 may also be formed of quartz, 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.

[0029] The liquid crystal panel 351 is disposed on the optical path of the blue light LB emitted from the light guide member 161, and is disposed 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 disposed at a position on the -Y side with respect to 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 according to 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.

[0030] 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) 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 electric 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 via the dustproof glass 311 by the operation of the switching element corresponding to the above electric signal, and generates the image light IB. The liquid crystal panel 351 emits the image light IB along the Y direction to the -Y side.

[0031] The dust-proof glass 311 has a plate surface parallel to the XZ plane, is disposed in a position overlapping with the light guide member 161 in the X direction and the Z direction, and is disposed on the +Y side most closely at the liquid crystal panel 351. The plate surface on the +Y side of the dust-proof glass 311 contacts 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 substances such as dust from blocking the blue light LB from entering the pixel constituting portion in the liquid crystal panel 351 from the +Y side. The pixel constituting 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 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 having excellent light transmittance and heat dissipation properties, for example, but may also be formed of quartz, optical glass, or the like.

[0032] The emission-side polarizing plate 361 is disposed on the optical path of the image light IB emitted from the liquid crystal panel 351, is disposed in a position overlapping with the liquid crystal panel 351 in the X direction and the Z direction, and is disposed on the -Y side most closely at 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 contacts, 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 specified polarization component in 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 specified polarization in the image light IB. The specified polarized light is, for example, P polarized light. That is, the specified polarized light is a 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 a reflection type polarizing plate having a transmission axis with respect to the specified polarized light. In addition, 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 plate 361.

[0033] The green light emitting unit 102 is disposed at a position on the -X side and the -Y side with respect to the blue light emitting unit 101, and is disposed in a region overlapping with 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.

[0034] The green light emitting unit 102 includes a light source 122, a collimating element 132, a condensing element 142, a diffusion device 151B, and a light guide member 162. The green light emitting unit 102 has, 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 the ratio of the required light amount of the green light LG emitted from the green light emitting unit 102 toward the photosynthesis unit 200 to the light amount of the green light LG emitted from one light source 122, and the like.

[0035] The light source 122 is supported by the substrate 112. The light source 122 is disposed on the +X side surface of the substrate 112 in a plane parallel to the YZ plane including the Y direction and the Z direction, and is arranged, for example, at intervals in the Y direction. The substrate 112 is formed of, for example, metal, alloy, etc., but may also be formed of an insulator such as resin like the substrate 111. Metal wirings and electrodes (not shown) are disposed on the +X side surface of the substrate 112. The metal wirings and electrodes provided on the substrate 112 are connected to the light source 122.

[0036] 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 of the surface of the light source 122 that contacts the +X side surface of the substrate 112 in the X direction. The light source 122 corresponds to the second light source and emits green light LG in the visible band and linearly polarized light. The green light LG corresponds to the second light. The polarization direction of the green light LG is along any one direction, for example, parallel to 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, diverges at an angle corresponding to the size of the light emitting surface and the peak wavelength of the green light LG, etc., with the axis passing through the center of the light emitting surface of the light source 122 and parallel to the X direction as the center, and travels toward the +X side. The green band is, for example, a band of 520 nm to 620 nm.

[0037] The light source 122 is constituted by, for example, an LD that emits the green light LG. In addition, when there are a plurality of light sources 122 in the green light emitting unit 102, two or more light sources 122 may be arranged at intervals in the Z direction in addition to the Y direction on the +X side surface of the substrate 112, or may be arranged at intervals only in the Z direction.

[0038] The green light emitting unit 102 has the same number of parallelizing elements 132 as the light sources 122. One of the plurality of parallelizing elements 132 is arranged corresponding to one of the plurality of light sources 122. The parallelizing element 132 is disposed on the optical path of the green light LG emitted from the light source 122 corresponding one by one. The parallelizing element 132 is disposed at a position overlapping the light source 122 in the Y direction and the Z direction, and is disposed at a position closer to the +X side than the light source 122. The incident surface of the parallelizing element 132 faces the emission surface of the light source 122. The parallelizing element 132 parallelizes the green light LG emitted from the light source 122 in a state of diverging radially with the optical axis parallel to the X direction, and emits the parallelized green light LG along the X direction toward the +X side.

[0039] The condensing element 142 is disposed at a position overlapping the area occupied by the same number of collimating elements 132 as the light source 122 in the Y direction and the Z direction, and is disposed on the +X side with respect to the collimating elements 132. The condensing element 142 corresponds to the second condensing element. The condensing element 142 sums up the light beams of a plurality of green lights LG emitted along the X direction from the collimating elements 132, emits them along the X direction to the +X side, 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 surface facing the incident side of the green light LG, but may also 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.

[0040] 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 circular when viewed along the X direction, and has an appropriate thickness in the X direction. The center of the YZ plane of the diffusion substrate 152B is offset from the optical axis of the green light LG emitted from the condensing element 142. For example, it is disposed on the +Y side with respect to the optical axis of the green light LG, and is disposed 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 condensing element 142 intersects between a specified position shifted outward from the center in the radial direction with respect to the center of the YZ plane of the diffusion substrate 152B and the outer peripheral end. The above-mentioned specified position corresponds to the position overlapping the outer edge of the driving device 153B in the radial direction with respect to the center of the YZ plane of the diffusion substrate 152B when viewed along the X direction.

[0041] The driving device 153B is disposed on the +Y side with respect to the optical path of the green light LG emitted from the condensing element 142, is disposed on the -X side with respect to the diffusion substrate 152B, and is disposed within a range overlapping the optical path of the green light LG in the Z direction. The driving device 153B is coaxially connected to the diffusion substrate 152B with respect to the rotation axis passing through the center of the YZ plane of the diffusion substrate 152B. The green light LG incident 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 diffuses 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 in the same manner as the diffusion surface of the diffusion substrate 152A.

[0042] The light guide member 162 is disposed on the optical path of the green light LG emitted from the diffusion substrate 152B of the diffusion device 151B, and is arranged at a position on the +X side with respect to the diffusion substrate 152B. The light guide member 162 is formed in a long strip shape along the X direction. The central axis in the YZ plane of the light guide member 162 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 that is emitted from the condenser element 142 and diffused by the diffusion device 151B to the +X side, and is incident on the liquid crystal panel 352 for green via the dust-proof glass 312.

[0043] In the optical path of the green light LG from the light emitting surface of the light source 122 in the green light emitting section 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 parallel to 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 components are respectively applied to the parallelizing element 132, the condenser element 142, the diffusion substrate 152B of the diffusion device 151B, and the light guide member 162, which are arranged at positions subsequent to the light source 122. The parallelizing element 132, the condenser element 142, the diffusion substrate 152B, and the light guide member 162 may also 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 section 102, is formed of quartz is effective for maintaining the polarization direction of the green light LG.

[0044] The liquid crystal panel 352 is disposed on the optical path of the green light LG emitted from the light guide member 162, and is arranged at a position overlapping the light emitting face 162b of the light guide member 162 in the Y direction and the Z direction, and is arranged at a position on the +X side with respect to the light guide member 162. The liquid crystal panel 352 corresponds to the second liquid crystal panel, and modulates the green light LG that is emitted from the light guide member 162 and passes through the dust-proof glass 312 according to 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 a green image light IG.

[0045] 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 in the Y direction and the Z direction along 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 via the dust-proof glass 312 by the operation of the switching element corresponding to the above 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.

[0046] 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 -X side most closely to the liquid crystal panel 352. The -X side plate surface of the dust-proof glass 312 contacts the +X side end surface, i.e., the light emitting surface 162b, of the light guide member 162. The dust-proof glass 312 prevents substances such as dust from entering the liquid crystal panel 352 that block the propagation of the green light LG to the light synthesis member 200. The dust-proof glass 312 is formed of a material that transmits at least light in the green wavelength band in the visible wavelength band, 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.

[0047] The emission-side polarizing plate 362 is disposed 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 +X side most closely to 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 contacts, for example, the +X side plate surface parallel to the YZ plane in the liquid crystal panel 352, i.e., the light emitting surface from which the image light IG is emitted in the +X direction. The emission-side polarizing plate 362 emits a specified polarization component in the image light IG emitted from the liquid crystal panel 352 in the +X direction along the X direction, and shields components other than the specified polarization in the image light IG. The specified polarized light is, for example, P polarized light. The emission-side polarizing plate 362 is, for example, an absorption type or reflection type polarizing plate having a transmission axis with respect to the specified polarized light. In addition, 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 plate 362.

[0048] The red light emitting section 103 is disposed in a region overlapping the blue light emitting section 101 in the X direction and the Z direction, and is disposed on the +X side with respect to the green light emitting section 102. The red light emitting section 103 emits red light LR. The red light LR in the red light emitting section 103 travels in the +Y direction from the -Y side along the Y direction.

[0049] The red light emitting section 103 includes a light source 123, a collimating element 133, a condensing element 143, a diffusing device 151C, and a light guiding member 163. The red light emitting section 103 has, for example, four light sources 123 in the X direction. The number of light sources 123 included in the red light emitting section 103 is appropriately set according to the ratio of the required light amount of the red light LR emitted from the red light emitting section 103 toward the photosynthesis member 200 to the light amount of the red light LR emitted from one light source 123, etc.

[0050] The light source 123 is supported by a substrate 113. The light source 123 is disposed on the +Y side plate surface in the plate surface parallel to the XZ plane in the substrate 113, and is arranged, for example, at intervals in the Y direction. The substrate 113 is formed of, for example, metal, alloy, etc., but may also be formed of an insulator such as resin like the substrates 111 and 112. Metal wirings and electrodes (not shown) are disposed on the +Y side plate surface of the substrate 113. The metal wirings and electrodes disposed on the substrate 113 are connected to the light source 123.

[0051] The light emitting surface of the light source 123 is arranged substantially parallel to the XZ plane, and is the surface on the side opposite to the surface that contacts the +Y side plate surface of the substrate 113 in the light source 123 in the Y direction. The light source 123 corresponds to the third light source, and emits the red light LR in the red wavelength band in the visible wavelength band and linearly polarized 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, diverges at an angle corresponding to the size of the light emitting surface and the peak wavelength of the red light LR, etc., with the axis passing through the center of the light emitting surface of the light source 123 and parallel to the Y direction as the center, and travels toward the +Y side. The red wavelength band is, for example, a band of 600 nm to 680 nm.

[0052] The light source 123 is constituted by, for example, an LD that emits the red light LR. In addition, in the case where the red light emitting section 103 includes 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.

[0053] The red light emitting section 103 has the same number of collimating elements 133 as the light sources 123. One of the plurality of collimating elements 133 is arranged corresponding 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 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 at a position 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 from the light source 123 in a state of radially diverging around the optical axis parallel to the Y direction, and emits the collimated red light LR along the Y direction to the +Y side.

[0054] 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 at a position 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 beams of the plurality of red lights LR emitted along the Y direction from the collimating element 133, emits them along the Y direction to the +Y side, 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 it can also be an optical element other than a plano-convex lens such as a biconvex lens that can condense the incident red light LR as described above.

[0055] The diffusion device 151C has a diffusion substrate 152C and a driving device 153C. The diffusion substrate 152C has a diffusion surface along the XZ plane, is circular when observed along the Y direction, and has an appropriate thickness in the Y direction. The center of the XZ plane of the diffusion substrate 152C is deviated from the optical axis of the red light LR emitted from the condensing element 143, and is arranged, for example, at a position on the -X side of the optical axis of the red light LR, and is arranged at a position substantially the same as the optical axis of the red light LR in the Z direction. The optical axis of the red light LR emitted from the condensing element 143 intersects between a specified position after moving 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 above-mentioned specified position corresponds to the position overlapping the outer edge of the driving device 153C in the radial direction with respect to the center of the XZ plane of the diffusion substrate 152C when observed along the Y direction.

[0056] The driving device 153C is disposed at a position on the -X side of the optical path of the red light LR emitted from the condensing element 143, at a position on the -X side of the diffusion substrate 152C, and within a range overlapping the optical path of the red light LR in the Z direction. The driving device 153C is coaxially connected to the diffusion substrate 152C with respect to 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 diffuses 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. On the diffusion surface of the diffusion substrate 152C, a fine concavo-convex structure is formed in the same manner as the diffusion surface of the diffusion substrate 152A.

[0057] The light guide member 163 is disposed on the optical path of the red light LR emitted from the diffusion substrate 152C of the diffusion device 151C, at a position on the +Y side of the diffusion substrate 152C. The light guide member 163 is formed in a long strip shape along the Y direction. The central axis in the XZ plane of the light guide member 163 is parallel to the Y direction and overlaps 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 is incident on the liquid crystal panel 353 for red via the dust-proof glass 313.

[0058] In the optical path of the red light LR from the light emitting surface of the light source 123 in the red light emitting unit 103 to the end surface on the +Y side of the light guide member 163, that is, the emitting surface 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 forming region 357 of the liquid crystal panel 353 described later, or parallel to the Z direction, that is, the direction parallel to the short side of the image forming region 357 of the liquid crystal panel 353. In the optical path of the red light LR, polarization maintaining type elements or components are respectively applied to the parallelizing element 133, the condensing element 143, the diffusion substrate 152C of the diffusion device 151C, and the light guide member 163 disposed at a position subsequent to the light source 123. The parallelizing element 133, the condensing element 143, the diffusion substrate 152C, and the light guide member 163 may also be formed of quartz, 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 unit 103, is formed of quartz is effective for maintaining the polarization direction of the red light LR.

[0059] The liquid crystal panel 353 is disposed on the optical path of the red light LR emitted from the light guide member 163, and is arranged 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 arranged on the +Y side with respect to 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 dust-proof glass 313 according to the 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 a red image light IR.

[0060] 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 electric 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 via the dust-proof glass 313 by the operation of the switching element corresponding to the above electric signal, to generate the image light IR. The liquid crystal panel 353 emits the image light IR along the Y direction to the +Y side.

[0061] The dust-proof glass 313 has a plate surface parallel to the XZ plane, and is arranged at a position overlapping the light guide member 163 in the X direction and the Z direction, and is arranged on the -Y side closest to the liquid crystal panel 353. The -Y side plate surface of the dust-proof 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 dust-proof glass 313 prevents substances such as dust from entering the liquid crystal panel 353, which block the propagation of the red light LR to the light synthesizing member 200. The dust-proof glass 313 is formed of a material that transmits at least the red light band in the visible band, and is preferably formed of a material with excellent heat dissipation. The dust-proof 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, etc.

[0062] The emission-side polarizing plate 363 is disposed on the optical path of the image light IR emitted from the liquid crystal panel 353, and is disposed at a position overlapping the liquid crystal panel 353 in the X direction and the Z direction, and is disposed on the +Y side closest to 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 toward the +Y side. The emission-side polarizing plate 363 emits a specified polarization component in the image light IR emitted from the liquid crystal panel 353 toward the +Y side along the Y direction, and blocks components other than the specified polarization in the image light IR. The specified polarized light is, for example, P-polarized light. The emission-side polarizing plate 363 is, for example, an absorption-type or reflection-type polarizing plate having a transmission axis with respect to the specified polarized light. In addition, 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 plate 363.

[0063] The photosynthesis component 200 is disposed in a region where the optical paths of the blue image light IB emitted from the emission-side polarizing plate 361, the green image light IG emitted from the emission-side polarizing plate 362, and the red image light IR emitted from the emission-side polarizing plate 363 intersect. The photosynthesis component 200 synthesizes the image lights IB, IG, and IR, and emits the generated image light IM toward the +X side along the X direction.

[0064] The photosynthesis component 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 with respect to 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 with respect to the incident surface 210d, and is located on the +X side with respect to the incident surfaces 210c and 210e.

[0065] When viewed along the Z direction, the reflection film 211 is arranged in such a manner that it moves from the +X side to the -X side as it moves from the -Y side to the +Y side. When viewed along the Z direction, the reflection film 212 is arranged in such a manner that it moves from the -X side to the +X side as it moves from the -Y side to the +Y side. The reflection films 211 and 212 overlap with the incident surfaces 210c and 210e in the X direction, overlap with the incident surface 210d and the exit surface 210b in the Y direction, and overlap with the incident surfaces 210c, 210d, 210e and the exit surface 210b in the Z direction. The reflection film 211 reflects light in the blue wavelength band and allows light in the green and red wavelength bands to pass through. The reflection film 212 reflects light in the red wavelength band and allows light in the blue and green wavelength bands to pass through.

[0066] The dichroic prism 210 is formed of a transparent material that transmits light in the visible wavelength band. The reflection films 211 and 212 are formed of, for example, dielectric multilayer films.

[0067] The specified polarized light of the image light IB emitted from the exit-side polarizing plate 361 travels along the Y direction toward the -Y side, enters the interior of the dichroic prism 210 from the incident surface 210c, passes through the reflection film 212, is reflected by the reflection film 211, deflects in the X direction, and travels toward the +X side. The specified polarized light of the image light IG emitted from the exit-side polarizing plate 362 travels along the X direction toward the +X side, enters the interior of the dichroic prism 210 from the incident surface 210d, passes through the reflection films 211 and 212, and travels straight toward the +X side. The specified polarized light of the image light IR emitted from the exit-side polarizing plate 363 travels along the Y direction toward the +Y side, enters the interior of the dichroic prism 210 from the incident surface 210e, passes through the reflection film 211, is reflected by the reflection film 212, deflects in the X direction, and travels toward the +X side.

[0068] The image lights IB, IG, and IR emitted from the reflection films 211 and 212 of the dichroic prism 210 toward the +X side are synthesized with each other to generate a full-color image light IM. The dichroic prism 210 emits the image light IM from the exit surface 210b toward the +X side along the X direction.

[0069] The projection optical system 450 is disposed on the optical path of the image light IM emitted from the light synthesis unit 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 magnifies and displays the image sent from an image forming device (not shown) to the liquid crystal panels 351, 352, and 353 on the screen SC. The projection optical system 450 is formed of, for example, one or more optical lenses arranged along the X direction. The optical lenses include, for example, plano-convex lenses, plano-concave lenses, biconvex lenses, biconcave lenses, meniscus lenses, aspherical lenses, free-form lenses, and the like.

[0070] Next, taking the blue light emitting section 101 as an example, the structure of the light guiding member of the light emitting section for each color light and the like will be described. Figure 2 is an enlarged view of a part of the projector 501, and is a schematic view when observing the blue light emitting section 101 and the liquid crystal panel 351 from the +X side toward the -X side along the X direction. In addition, in Figure 2 the substrate 111 is omitted.

[0071] As Figure 2 shown, the light guiding 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.

[0072] The incident surface 161a is the end surface on the +Y side of the light guiding member 161, is parallel to the XZ plane, and in the present embodiment, is substantially similar to the spot shape of the blue light LB converged by the condenser element 141. In addition, the shape of the incident surface 161a may not be similar to the spot shape of the blue light LB. The shape of the incident surface 161a when observed 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 also be a square shape.

[0073] The emission surface 161b is the end surface on the -Y side of the light guiding 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 emission surface 161b when observed 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 size of the image forming region 355 in the X direction is larger than the size of the image forming region 355 in the Z direction. The aspect ratio of the size of the emission surface 161b in the X direction to the size in the Z direction corresponds to the aspect ratio of the size of the image forming region 355 in the X direction to the size in the Z direction, and is, for example, 3:4, 4:5, 9:16, etc.

[0074] The imaginary line connecting the center of the incident surface 161a and the center of the emission surface 161b is substantially parallel to the Y direction. The size of the emission surface 161b in the X direction is larger than the size of the incident surface 161a in the X direction. The size of the emission surface 161b in the Z direction is larger than the size of the incident surface 161a in the Z direction. The area of the emission surface 161b is larger than the area of the incident surface 161a.

[0075] The light guide member 161 has four side surfaces 161s. The first side surface 161s among the four side surfaces 161s connects the long side on the +Z side of the two long sides parallel to the X direction of the incident surface 161a and the long side on the +Z 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. The second side surface 161s among the four side surfaces 161s connects the long side on the -Z side of the two long sides parallel to the X direction of the incident surface 161a and the long side on the -Z 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. The third side surface 161s among the four side surfaces 161s connects the short side on the +X side of the two short sides parallel to the Z direction of the incident surface 161a and the short side on the +X 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 perpendicular to the third side surface 161s. The fourth side surface 161s among the four side surfaces 161s connects the short side on the -X side of the two short sides parallel to the Z direction of the incident surface 161a and the short side on the -X 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.

[0076] The four side surfaces 161s are each inclined as a whole in the Y direction 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 cone 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.

[0077] Figure 3 is a perspective view of the light guide member 161. As Figure 3 shown, the light guide member 161 is a solid frustum of a quadrangular pyramid surrounded by the incident surface 161a, the emission surface 161b, and the four side surfaces 161s. As described above, the solid light guide member 161 is formed of a transparent material that has light transmittance and heat dissipation properties for the blue light LB, well maintains 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 quadrangular pyramid. The emission surface 161b corresponds to the bottom surface of the frustum of the quadrangular pyramid. The length of the light guide member 161 in the Y direction corresponds to the height of the frustum of the quadrangular pyramid.

[0078] The light guide member 161 is composed of an incident surface 161a, an emission surface 161b, and an inclined portion 161t. The inclined portion 161t connects between the incident surface 161a and the emission surface 161b in the Y direction and is surrounded by four side surfaces 161s on the XZ plane. The central axis of the light guide member 161 in the shape of a frustum of a square pyramid and the inclined portion 161t is parallel to the Y direction and parallel to the optical axis AX1 of the entire blue light LB that is incident on the incident surface 161a from the +Y side and totally reflected on the side surface 161s and propagates in the inclined portion 161t. As described above, the emission surface 161b is larger than the incident surface 161a, and the centers of the incident surface 161a and the emission surface 161b overlap each other in the XY plane. Therefore, the area of the cut surface parallel to the XZ plane that intersects the inclined portion 161t and the Y direction and the optical axis AX1, that is, the cross-sectional area of the inclined portion 161t increases as it advances from the +Y side to the -Y side.

[0079] Return Figure 1 , as described above, the blue light LB that is converged by the condenser lens 141 and emitted from the diffusion substrate 152A of the diffusion device 151A is incident on the light guide member 161. The blue light LB is incident on the incident surface 161a of the light guide member 161 from the +Y side along the Y direction. 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 by the blue light LB incident on the inside of the light guide member 161 from the incident surface 161a with respect to the optical axis are not constant and have a range corresponding to the refractive power of the condenser lens 141 and the like.

[0080] 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 on the inside of the light guide member 161 from the incident surface 161a, the blue light LB whose angle formed with respect to the optical axis AX1 is below the cone angle of the side surface 161s directly reaches the emission surface 161b. Among the blue light LB incident on the inside of the light guide member 161 from the incident surface 161a, the blue light LB whose angle formed with respect to the optical axis AX1 is larger than the cone angle of the side surface 161s is totally reflected by the side surface 161s and reaches the emission surface 161b. By the total reflection of the blue light LB on the side surface 161s, the amount of light of the reflected blue light LB is increased compared with the case where it is reflected by a reflection film composed of a dielectric multilayer film or the like (not shown) on the side surface 161s. The number of times the blue light LB whose angle formed with respect to the optical axis AX1 is larger than the cone angle of the side surface 161s is totally reflected by the side surface 161b varies according to the angle formed with respect to the optical axis AX1. At the emission surface 161b, blue light LB with different paths and incident angles is incident, and as a result, the illuminance distribution of the blue light LB is homogenized.

[0081] Blue light LB with a uniform illuminance distribution 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 larger than the image formation region 355 of the liquid crystal panel 351 by an amount of illumination margin in such a way that the illumination margin is included 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.

[0082] In order to efficiently total reflect the blue light LB on the side surface 161s in the light guide member 161 and achieve uniformization of the illuminance distribution of the blue light LB 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. As the transparent material of the light guide member 161, as described above, quartz, optical glass, etc. can be cited, and quartz is preferably used from the aspect of 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°.

[0083] As Figure 2 shown, the liquid crystal panel 351 has a dust-proof glass 311, a counter substrate 391, a liquid crystal layer 392, an element substrate 393, and an emission-side polarizing plate 361 that are sequentially stacked and arranged in the Y direction from the +Y side toward the -Y side. The dust-proof glass 311 is disposed on the incident side of the blue light LB with respect to the counter substrate 391 and serves as an incident-side dust-proof member. The counter substrate 391, the liquid crystal layer 392, and the element substrate 393 are pixel constituent parts of the liquid crystal panel 351 and constitute a plurality of pixels.

[0084] The plate surface of the dust-proof glass 311 is larger than the emission surface 161b of the light guide member 161 in the X direction and the Z direction. The +Z-side end of the dust-proof glass 311 is closer to 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 dust-proof glass 311 is closer to 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 dust-proof glass 311 are located at positions closer to the ±X sides 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 dust-proof glass 311 overlaps with the optical axis AX1 of the blue light LB.

[0085] The opposed substrate 391 corresponds to the first substrate. The surface of the opposed substrate 391 is slightly larger than the light-emitting surface 161b of the light guide member 161 in the X direction and the Z direction, smaller than the surface of the dust-proof glass 311, and at least larger than the image formation region 355. The center of the surface of the opposed substrate 391 overlaps with the optical axis AX1 of the blue light LB. The +Y side surface of the opposed substrate 391 contacts the -Y side surface of the dust-proof glass 311. Opposed electrodes corresponding to the respective pixels and the like are formed on the -Y side surface of the opposed substrate 391.

[0086] The liquid crystal layer 392 is disposed in the image formation region 355 of the liquid crystal panel 351 and is configured in a rectangular shape that constitutes the image formation region 355 when viewed along the Y direction, and is sandwiched between the opposed substrate 391 and the element substrate 393 in the Y direction. A plurality of liquid crystal molecules (not shown) are included in the liquid crystal layer 392. Around the liquid crystal layer 392 in the XZ plane, a layer structure (not shown) that forms a 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 formation region 355 are disposed.

[0087] The element substrate 393 corresponds to the second substrate. The surface of the element substrate 393 has the same size as the opposed substrate 391 in the X direction and the Z direction, and overlaps with the opposed substrate 391 when viewed along the Y direction. The center of the surface of the element substrate 393 overlaps with the optical axis AX1 of the blue light LB. Pixel electrodes corresponding to the respective pixels, TFTs constituting switching elements, a liquid crystal alignment film, and the like are formed on the -Y side surface of the element substrate 393. The +Y side surface of the element substrate 393 contacts the -Y side surface of the emission-side polarizing plate 361. When viewed along the Y direction, the element substrate 393 and the opposed substrate 391 are formed in the same size and rectangular shape, and are respectively formed larger than the image formation region 355 in the X direction and the Z direction. The element substrate 393 and the opposed substrate 391 sandwich the liquid crystal layer 392, the layer structure (not shown) constituting the peripheral region, and the peripheral region structure including the sealing material and support them.

[0088] 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 surface of the emission-side polarizing plate 361 has the same size as the opposed substrate 391 and the element substrate 393 in the X direction and the Z direction, and overlaps with the opposed substrate 391 and the element substrate 393 when viewed along the Y direction. The center of the surface of the emission-side polarizing plate 361 overlaps with the optical axis AX1 of the blue light LB. By disposing the emission-side polarizing plate 361, substances such as dust that block the propagation of the blue light LB to the photosynthesis member 200 are prevented from entering the pixel constituting portion in the liquid crystal panel 351 from the -Y side. The emission-side polarizing plate 361 corresponds to the emission-side dust-proof member.

[0089] Figure 4 This is an image showing the result of calculating the illuminance distribution on the incident surface on the +Y side of the liquid crystal layer 392 of the liquid crystal panel 351 through numerical simulation under the condition that parameters related to the dimensions and materials of each element and the light guide member 161 are appropriately set in the blue light emitting portion 101 having the above structure. Figure 5 This is showing that under the same conditions as the numerical simulation for obtaining the Figure 4 image, when the length of the light guide member 161 in the Y direction is reduced and the emission surface 161b of the light guide member 161 is moved toward the +Y side, this is an image showing the result of calculating the illuminance distribution on the incident surface on the +Y side of the liquid crystal layer 392 of the liquid crystal panel 351 through numerical simulation. For obtaining the Figure 5 image, the setting of the numerical simulation is the same as that in the numerical simulation for obtaining the Figure 4 image, in a state where there is a gap with a distance of at least more than 3 μm in the Y direction between the emission surface 161b of the light guide member 161 and the +Y side plate surface of the dust-proof glass 311.

[0090] In Figure 4 the image and Figure 5 the image, there are respectively an effective irradiation portion LAA and a peripheral portion LAC. The effective irradiation portion LAA is the portion including the central portion of the irradiation region in the XZ plane of the blue light LB, and refers to the portion where the illuminance of the blue light LB within a specified illuminance range that should be irradiated onto the image formation region 355 of the liquid crystal panel 351 is obtained. The peripheral portion LAC refers to the portion that is generated around the effective irradiation portion LAA in the XZ plane and where the illuminance of the blue light LB is lower than the aforementioned specified illuminance range.

[0091] In the blue light emitting portion 101 and the projector 501 of the first embodiment, since the emission surface 161b of the light guide member 161 is in contact with the +Y side plate surface of the dust-proof glass 311, the separation distance in the Y direction between the emission 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 thickness in the Y direction of the dust-proof glass 311 and the thickness in the Y direction of the counter substrate 391 of the liquid crystal layer 392. According to the comparison between Figure 4 the image and Figure 5 the image, it can be seen that in the structure of the blue light emitting portion 101 and the projector 501 shown in Figure 4 , the effective irradiation portion LAA of the blue light LB is ensured to be relatively wide, and the peripheral portion LAC is suppressed to be relatively narrow.

[0092] As Figure 5As shown, it was confirmed that, as with conventional projectors, 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, the effective irradiation portion LAA of the blue light LB becomes relatively narrow and the peripheral portion LAC expands relatively. 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 an effective irradiation portion LAA having the same size 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, enlargement of the light guide member 161 is required. In addition, 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, the peripheral portion LAC is relatively wider with respect to the irradiation region of the blue light LB than in the case where no gap is generated. Therefore, the utilization efficiency of the blue light LB may decrease.

[0093] According to the results of the above numerical simulation, by bringing the light-emitting surface 161b of the light guide member 161 into contact with the +Y-side plate surface of the dust-proof glass 311, enlargement 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. The utilization efficiency of the blue light LB, that is, the amount of light that is irradiated onto the image formation region 355 of the liquid crystal panel 351 and converted into image light IB with respect to the amount of blue light LB emitted from the light source 121 is increased.

[0094] Return Figure 2 , the cooling fan 481 mainly supplies the cold air W to the extension portion that extends more toward the -Z side than the -Z-side end portion of the light-emitting surface 161b of the light guide member 161 at the dust-proof glass 311. The -Z-side extension portion of the dust-proof glass 311 receives the cold air W from the cooling fan 481, and thus is cooled from the -Z side to the +Z side, the -X side, and the +X side. The cold air W from the cooling fan 481 can be directly supplied from the +Y side and the -Z side to the -Z-side extension portion of the dust-proof glass 311, or can be supplied from the +Y side and the -Z side via a pipe (not shown) or the like.

[0095] In addition, the dust-proof glass 311 extends more toward the +Z side and the ±X side than the light-emitting surface 161b of the light guide member 161. The cooling fan 481 can also supply the cold air W to the extension portion that extends toward any one of the +Z side or the ±X side in the dust-proof glass 311 when viewed along the Y direction and is more extended than the light-emitting surface 161b. The arrangement of the cooling fan 481 is appropriately determined inside or outside a housing (not shown) of the projector 501.

[0096] 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. As described above, the counter substrate 391 exchanges heat with the dust-proof glass 311 cooled by the cold air W from the cooling fan 481. 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.

[0097] When the image light IB is generated in the image formation region 355 of the liquid crystal panel 351, the element substrate 393 is heated more than 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 past. Since the element substrate 393 is cooled and, as described above, the counter substrate 391 is also cooled, excessive temperature rise and performance deterioration of the liquid crystal panel 351 are suppressed, and the conversion efficiency of the blue light LB into the image light IB is improved.

[0098] A part of the cold air W from the cooling fan 481 is supplied from the -Z side to the -Z side surface 161s of the light guide member 161. Thereby, in addition to the dust-proof glass 311, the light guide member 161 is also cooled.

[0099] Although not shown, the green light emitting portion 102 and the red light emitting portion 103 are configured in the same manner as the blue light emitting portion 101 described above. The description of the green light emitting portion 102 is obtained by replacing the light source 121 with the light source 122, the parallelizing element 131 with the parallelizing element 132, the condensing element 141 with the condensing element 142, the diffusion device 151A with the diffusion device 151B, the light guide member 161 with the light guide member 162, the emission surface 161b with the emission 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 in the description of the blue light emitting portion 101.

[0100] The liquid crystal panel 352 is configured in the same manner as the liquid crystal panel 351 described above. The description of the liquid crystal panel 352 is obtained by replacing the dust-proof glass 311 with the dust-proof glass 312, the emission-side polarizing plate 361 with the emission-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 in the description of the liquid crystal panel 351. Between the dust-proof glass 312 and the emission-side polarizing plate 362, the counter substrate, the liquid crystal layer, and the element substrate of the liquid crystal panel 352 are arranged in order from the -X side toward the +X side.

[0101] The description of the red light emitting unit 103 is obtained by replacing the light source 121 with the light source 123, the parallelizing element 131 with the parallelizing element 133, the condensing element 141 with the condensing element 143, the diffusion device 151A with the diffusion device 151C, the light guide member 161 with the light guide member 163, the light emitting surface 161b with the light emitting surface 163b, the blue light LB with the red light LR, the +Y side with the -Y side, and the -Y side with the +Y side in the description of the blue light emitting unit 101.

[0102] The liquid crystal panel 353 has the same pointer configuration as the liquid crystal panel 351 described above. The description of the liquid crystal panel 353 is obtained by replacing the dust-proof glass 311 with the dust-proof glass 313, the emission-side polarizing plate 361 with the emission-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 emission-side polarizing plate 363, the counter substrate, the liquid crystal layer, and the element substrate of the liquid crystal panel 353 are arranged in order from the -Y side toward the +Y side.

[0103] Return Figure 1 The cooling fan 482 mainly supplies cold air (air) to the 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. The -Z side extending portion of the dust-proof glass 312 receives the cold air from the cooling fan 482, whereby the dust-proof glass 312 is cooled. The cold air from the cooling fan 482 can be directly supplied to the -Z side extending portion of the dust-proof glass 312 from the -X side and the -Z side, or can be supplied from the -X side and the -Z side via a pipe (not shown) or the like. Also, the cooling fan 482 can supply cold air to the extending portion that extends to either the +Z side or either the ±X side in the dust-proof glass 312 when viewed along the X direction than the light emitting surface 162b. The arrangement of the cooling fan 482 is the same as that of the cooling fan 481, and is appropriately determined inside or outside the housing (not shown) of the projector 501.

[0104] The dust-proof glass 312 is cooled from the -Z side end by the cold air from the cooling fan 482, and the entire +Z side end is efficiently cooled. Heat exchange is performed 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.

[0105] When generating image light IG in the image formation region 356 of the liquid crystal panel 352, the element substrate of the liquid crystal panel 352 is further heated compared to the counter substrate. The element substrate of the liquid crystal panel 352 is cooled by a dedicated cooling fan (not shown) as in the past. 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 green light LG to image light IG is improved.

[0106] A 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. Therefore, in addition to the dust-proof glass 312, the light guide member 162 is also cooled.

[0107] The cooling fan 483 mainly supplies cold air (air) to the 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. The -Z side extension portion of the dust-proof glass 313 receives the cold air from the cooling fan 483, whereby the dust-proof glass 313 is cooled. The cold air from the cooling fan 483 can be directly supplied from the -X side and the -Z side to the -Z side extension portion of the dust-proof glass 313, or can be supplied from the -X side and the -Z side via a pipe (not shown) or the like. Also, the cooling fan 483 can supply cold air to the extension portion that extends to either the +Z side or the ±X side in the dust-proof glass 313 when viewed from the Y direction compared to the light emitting surface 163b. The arrangement of the cooling fan 483 is the same as that of the cooling fan 481 and is appropriately determined inside or outside the housing (not shown) of the projector 501.

[0108] The dust-proof glass 313 is cooled from the -Z side end by the cold air from the cooling fan 483, and the entire +Z side end is efficiently cooled. Heat exchange is performed 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.

[0109] When generating image light IR in the image formation region 357 of the liquid crystal panel 353, the element substrate of the liquid crystal panel 353 is further heated compared to the counter substrate. The element substrate of the liquid crystal panel 353 is cooled by a dedicated cooling fan (not shown) as in the past. 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 red light LR to image light IR is improved.

[0110] 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. Therefore, in addition to the dust-proof glass 313, the light guide member 163 is also cooled.

[0111] 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 cut surface of the inclined portion 161t that intersects the Y direction parallel to the optical axis AX1 increases as it advances toward the -Y side along the Y direction (the direction of guiding the first light) for guiding the blue light LB. In the projector 501 of the first embodiment, the emission surface 161b of the light guide member 161 is in contact with a part (a part on the light incident side) of the incident side of the blue light LB in the liquid crystal panel 351. For example, a part of the incident side of the blue light LB in the liquid crystal panel 351 is a part of the +Y side plate surface of the dust-proof glass 311 where the blue light LB is incident, and when viewed along the Y direction, it is a region (a part) that includes the center of the +Y side plate surface of the dust-proof glass 311 and overlaps with the emission surface 161b of the light guide member 161.

[0112] In the projector 501 of 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 is incident on the blue liquid crystal panel 351 via an optical system including the light guide member 161. The green light LG is incident on the green liquid crystal panel 352 via an optical system including the light guide member 162. The red light LR is incident on the red liquid crystal panel 353 via an optical system including the light guide member 163.

[0113] In the projector 501 of the first embodiment, since the emission surface 161b on the -Y side of the light guide member 161 is in contact with a part of the +Y side plate surface of the dust-proof glass 311 of the liquid crystal panel 351, it is possible to suppress the leakage of the blue light LB to the outside of the light guide member 161 and the liquid crystal panel 351 in the Y direction and on the XZ plane, and the blue light LB emitted from the light guide member 161 is efficiently incident on the liquid crystal panel 351.

[0114] In addition, in the projector 501 of the first embodiment, the state in which the light emitting surface 161b of the light guide member 161 is in contact with a part of the +Y side plate surface of the dustproof glass 311 includes a state in which the light emitting surface 161b and a part of the +Y side plate surface of the dustproof glass 311 respectively have the same flatness and have the same fine irregularities in the XZ plane and are in overall contact with each other's surfaces. The state in which the light emitting surface 161b is in contact with a part of the +Y side plate surface of the dustproof glass 311 also includes the following state: one of the light emitting surface 161b and a part of the +Y side plate surface of the dustproof glass 311 has a flatness different from that of the other surface and fine irregularities in the XZ plane different from those of the other surface, and a deviation occurs in the separation distance in the Y direction between the light emitting surface 161b and a part of the +Y side plate surface of the dustproof 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.

[0115] 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 improved. In the following description, the description of the effects related to the blue light emitting unit 101 and the cooling fan 481 of the projector 501 of the first embodiment is also applied to the green light emitting unit 102 and the red light emitting unit 103 having the same configuration as the blue light emitting unit 101, respectively. 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 the green light LG emitted from the light source 122 and the red light LR emitted from the light source 123 can also be improved.

[0116] In a conventionally known first projector, for example, a light emitting diode (LED) is provided as a light source, the parallelism of the light emitted from a plurality of LEDs is improved by a conical 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 light combining member, is incident on a liquid crystal cell (liquid crystal panel), is converted into image light, and is projected through a projection optical system or the like (for example, Japanese Patent Laid-Open No. 2008-083661). In the first projector, the light emitting surface of the rod member is in contact with the incident surface of the cubic polarization beam splitter of the polarization conversion unit.

[0117] In a conventional first projector, a gap is provided between the light-emitting 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 light-emitting 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 light-emitting surface of the polarization beam splitter and the incident surface of the liquid crystal cell, which is considerably larger than the thicknesses of the components such as the known dust-proof glass, incident-side polarizing plate, and 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 with respect to the image formation region of the liquid crystal cell is relatively large.

[0118] In the blue light emitting section 101 of the projector 501 according to the first embodiment, as described above, the light-emitting surface 161b on the -Y side of the light guide member 161 is in contact with a part of the +Y side plate surface of the dust-proof glass 311 of the liquid crystal panel 351. Therefore, the separation distance in the Y direction between the light-emitting surface 161b and the liquid crystal layer 392 of the liquid crystal panel 351 is suppressed to be equal to the sum of the thickness of the dust-proof glass 311 and the thickness of the counter substrate 391. The illumination margin with respect to the image formation region 355 is relatively small compared to the conventional first projector. Similarly, the illumination margins with respect to the image formation regions 356 of the green light emitting section 102 and 357 of the red light emitting section 103 are relatively small compared to the conventional first projector. According to the projector 501 of the first embodiment, it is possible to prevent leakage of color light between the light guide members 161, 162, 163 and the dust-proof glasses 311, 312, 313 of the liquid crystal panels 351, 352, 353 respectively, suppress the illumination margins with respect to the image formation regions 355, 356, 357 to be small, and improve the light utilization efficiency of the blue light LB, green light LG, and red light LR.

[0119] In a conventional second projector, for example, the illuminance distributions of the blue light, green light, and red light emitted from the blue LED light source, green LED light source, and red LED light source respectively are homogenized by separate tapered rod lenses (light guide members). The color lights emitted from the tapered rod lenses pass through a reflective polarization element composed of a WGP (Wire Grid Polarizer), are incident on a liquid crystal light valve (liquid crystal panel), are converted into image light, and are projected by a projection optical system or the like (for example, Japanese Patent Laid-Open No. 2005-234440). In the second projector, the emission-side end surface of the tapered rod lens is in contact with the WGP.

[0120] In a conventional second projector, in the direction along the optical path, light leakage from the gap between the end face and the WGP can be prevented, and thus a reduction in light utilization efficiency due to light leakage from the above-described gap can be suppressed. However, since the color light emitted from the tapered rod lens passes through the WGP, a reduction in light utilization efficiency caused by the WGP occurs.

[0121] In the blue light emitting unit 101 of the projector 501 according to the first embodiment, as described above, the emission surface 161b of the light guide member 161 on the -Y side is in contact with a part of the +Y side plate surface of the dustproof glass 311 of the liquid crystal panel 351, and a polarizing plate is not disposed between the light guide member 161 and the counter substrate 391, which is the +Y side substrate of the liquid crystal panel 351. According to the projector 501 of the first embodiment, since no polarizing plate is disposed on the incident side of each of the liquid crystal panels 351, 352, and 353, a reduction in light utilization efficiency accompanied by light loss caused by absorption and reflection of 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 improved.

[0122] A conventional third projector has, for example, a light source device including: a light source unit having an LD light source; a phosphor as a wavelength conversion element that performs wavelength conversion on the light emitted from the light source unit; a light guide (light guide member) that guides the light emitted from the phosphor; a reflective polarizing element that adjusts the polarization direction of the light emitted from the light guide; and a reflecting mirror that is disposed to surround a portion of the light guide on the incident side with respect to the middle position. In the conventional third projector, the light emitted from the reflective polarizing element enters the inside of the light guide from the emission surface and propagates toward the incident surface, contributing to the re-excitation of the phosphor. The emission surface of the light guide is not in contact with the reflective polarizing element but is disposed separately from the reflective polarizing element.

[0123] In a conventional third projector, a liquid crystal light valve (liquid crystal panel) is disposed at a distance from a reflective polarization element on the side opposite to the light guide body. 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 body 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 body and the incident surface of the reflective polarization element, the thickness of the reflective polarization element, and the separation distance between the light emitting surface of the reflective polarization element and the incident surface of the liquid crystal light valve, which is considerably larger than the thicknesses of the components such as the known dust-proof glass, incident-side polarizing plate, and 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 body and the reflective polarization element and between the reflective polarization element and the liquid crystal light valve, and the illumination margin for the image formation regions of the liquid crystal cells is relatively large. In addition, in the conventional third projector, a reflective polarization 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 polarization element and does not enter the liquid crystal light valve, resulting in a reduction in light utilization efficiency.

[0124] As described above, in the projector 501 according to the first embodiment, 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, and the illumination margin for each of the image formation regions 355, 356, 357 is suppressed to be small. Without assuming loss of color light in the polarizing elements on the incident side of the liquid crystal panels 351, 352, 353, the light utilization efficiency of the blue light LB, green light LG, and red light LR can be improved.

[0125] In the projector 501 according to the first embodiment, the polarization direction of the linearly polarized blue light LB emitted from the light source 121 is not changed by, for example, a polarizing plate or a polarization element other than a 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.

[0126] 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 suppressed to the minimum.

[0127] In the projector 501 according to the first embodiment, the shape of the cross section of the light guide member 161 perpendicular to the optical axis AX1 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 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.

[0128] In the projector 501 of the first embodiment, at the time 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 preferable as the polarization direction of the blue light LB that enters the image forming region 355 of the liquid crystal panel 351. According to the projector 501 of the first embodiment, it is possible to suppress the loss of the light quantity of the blue light LB before it is guided by the light guide member 161 and enters the liquid crystal layer 392 of the liquid crystal panel 351 to the minimum, and it is easy to control the blue light LB in each pixel of the image forming region 355 of the liquid crystal panel 351 to generate image light LB.

[0129] 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 has 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 arranged on the +Y side (light incident side) with respect to the counter substrate 391. The emission side polarizing plate 361 is arranged on the -Y side (light emission side) with respect to the element substrate 393. In the projector 501 of the first embodiment, the emission surface 161b of the light guide member 161 is in contact with the dustproof glass 311.

[0130] In the projector 501 of the first embodiment, specifically, in the XY plane of the dustproof glass 311 arranged closest to the +Y side in the liquid crystal panel 351, the portion that overlaps the emission surface 161b of the light guide member 161 when observed along the Y direction is in contact with the emission 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, it is possible to suppress the gap between the emission surface 161b of the light guide member 161 and the incident surface of the liquid crystal layer 392 of the liquid crystal panel 351 to be equal to the sum of the thickness of the dustproof glass 311 and the thickness of the counter substrate 391. As a result, it is possible to prevent the leakage of color light between the light guide member 161 and the dustproof glass 311 well, and suppress the illumination margin for the image forming region 355 to be small.

[0131] The projector 501 of the first embodiment further has a cooling fan 481 that conveys cold air (air) W to the liquid crystal panel 351. In the projector 501 of the first embodiment, the planar size of the dustproof glass 311 when observed along the optical axis AX1 of the blue light LB and the Y direction, that is, the size on the XY plane, is larger than the planar sizes of the counter substrate 391, the element substrate 393, and the emission side polarizing plate 361 respectively. The cooling fan 481 conveys cold air W to the dustproof glass 311.

[0132] In the projector 501 according to the first embodiment, the cold air W is conveyed from the cooling fan 481 to an extension portion that is larger than the opposed substrate 391, the element substrate 393, and the emission-side polarizing plate 361 when viewed in the Y direction in the dustproof glass 311. By the cold air W from the cooling fan 481, mainly the dustproof glass 311 is directly cooled, and the light guide member 161 and the opposed substrate 391 in contact with the dustproof glass 311 are indirectly cooled. The element substrate 393 is cooled by the same method as in the past. As a result, excessive temperature rise and malfunction of the liquid crystal panel 351 caused by irradiation with the blue light LB are prevented. According to the projector 501 of the first embodiment, deterioration of the performance of the liquid crystal panel 351 can be effectively suppressed, and the liquid crystal panel 351 can be used for a long time.

[0133] In the projector 501 according to the first embodiment, the cooling fan 481 also conveys the cold air W to the light guide member 161.

[0134] In the projector 501 according to the first embodiment, a part of the cold air W from the cooling fan 481 cools the light guide member 161. According to the projector 501 of the first embodiment, heat can be received from the dustproof 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 dustproof glass 311. In addition, according to the projector 501 of the first embodiment, disturbance of the polarization direction of the blue light LB propagating inside the light guide member 161 can be suppressed.

[0135] The projector 501 according to 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.

[0136] In the projector 501 according to 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 rotating in the diffusion device 151A. According to the projector 501 of the first embodiment, uniformization 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 emission surface 161b of the light guide member 161 can be improved.

[0137] The projector 501 according to 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 of guiding the second light) in which the green light LG is guided. In the projector 501 according to the first embodiment, the emission surface 162b of the light guide member 162 is in contact with a part (a part on the light incident side) of the liquid crystal panel 352 on the incident side of the green light LG. For example, a part of the liquid crystal panel 352 on the incident side of the green light LG is a part of the -X side plate surface of the dustproof glass 312 on which the green light LG is incident, and when viewed along the X direction, it is a region (a part) that includes the center of the -X side plate surface of the dustproof glass 321 and overlaps with the emission surface 162b of the light guide member 162.

[0138] The projector 501 according to the first embodiment further includes a light source 123 that emits red light LR, a condenser 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. The red light LR emitted from the condenser element 143 is incident on the incident surface of the light guide member 163. The 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 according to the first embodiment, the emission surface 163b of the light guide member 163 is in contact with a part of the incident side of the red light LR in the liquid crystal panel 353. For example, a part of the incident side of the red light LR in the liquid crystal panel 353 is a part of the -X side plate surface where the red light LR is incident on the dustproof glass 313, and when viewed along the X direction, it is an area that includes the center of the -X side plate surface of the dustproof glass 313 and overlaps with the emission surface 163b of the light guide member 163.

[0139] In the projector 501 according to the first embodiment, since the emission surface 161b of the light guide member 162 on the +X side is in contact with a part of the -X side plate surface of the dustproof glass 312 of the liquid crystal panel 352, leakage of the green light LG to the outside of the light guide member 162 and the liquid crystal panel 352 in the X direction and the YZ plane is suppressed, and the green light LG emitted from the light guide member 162 is efficiently incident on the liquid crystal panel 352. In addition, since the emission surface 163b of the light guide member 163 on the +Y side is in contact with a part of the -Y side plate surface of the dustproof glass 313 of the liquid crystal panel 353, leakage of the red light LR to the outside of the light guide member 163 and the liquid crystal panel 353 in the Y direction and the XZ plane is suppressed, and the red light LR emitted from the light guide member 163 is efficiently incident on 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 can be improved, and the color light including the blue light LB, the green light LG, and the red light LR can be made brighter.

[0140] Modification of the First Embodiment

[0141] 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 dustproof glass 311 of the liquid crystal panel 351 and the -Y side end surface, i.e., the light emitting surface 161b, of the light guide member 161 of the blue light emitting unit 101. In addition, in this specification, the air layer is not shown.

[0142] The thickness of the air layer in the Y direction, i.e., the separation distance between the light emitting surface 161b and the +Y side plate surface of the dustproof glass 311, is 3 μm or less, preferably 1 μm or less. The upper limit value of such a separation distance of 3 μm is a separation distance that is regarded as substantially the same as the state of contact between the light guide member 161 and the dustproof glass 311, i.e., when the separation distance is 0 μm, and the same heat transfer and heat dissipation phenomena as when the separation distance is 0 μm occur, and is a dimension obtained through in-depth research and insights of the present inventors using numerical simulations and the like.

[0143] A modification of the projector 501 of the first embodiment includes a state in which at least a part (a portion) of the light emitting surface 161b and the +Y side plate surface of the dustproof glass 311 that overlap with the light emitting surface 161b when viewed along the Y direction respectively have the same flatness and the same fine irregularities on the XZ plane, and the surfaces of each other are in overall contact. Similar to the first embodiment, a modification of the projector 501 also includes a state in which one surface of a part of the light emitting surface 161b and the +Y side plate surface of the dustproof glass 311 has a different flatness and different fine irregularities on the XZ plane from the other surface, and a deviation occurs in the separation distance in the Y direction between a part of the light emitting surface 161b and the +Y side plate surface of the dustproof 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.

[0144] A modification of the projector 501 of the first embodiment 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. In a modification of the projector 501 of 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 (a part on the light incident side) of the liquid crystal panel 351 on the incident side of the blue light LB.

[0145] In a modification of the projector 501 according to the first embodiment, 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 dustproof glass 311 of the liquid crystal panel 351 is 3 μm or less. Therefore, in substantially the same manner as the state where the light-emitting surface 161b and a part of the +Y side plate surface of the dustproof glass 311 are in contact with each other, leakage of blue light LB in the Y direction and the XZ plane to the outside of the light guide member 161 and the liquid crystal panel 351 can be suppressed. In addition, when generating the image light IB, 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 dustproof glass 311 is suppressed to 3 μm or less, heat exchange and heat dissipation between the counter substrate 391, the dustproof glass 311, and the light guide member 161 are performed in substantially the same manner as the state where the light-emitting surface 161b and a part of the +Y side plate surface of the dustproof glass 311 are in contact with each other, and the entire end portion of the dustproof glass 311 on the -Z side is efficiently cooled. And, in a modification of the projector 501 according to the first embodiment, the illumination margin for each of the image formation regions 355, 356, 357 can be well suppressed. In addition, since no polarizing plate is disposed on the incident side of each of the liquid crystal panels 351, 352, 353, a reduction in light utilization efficiency caused by the polarizing plate does not occur on the incident side of each of the liquid crystal panels 351, 352, 353. Thus, in a modification 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 a modification 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 improved.

[0146] According to a modification of the projector 501 according to the first embodiment, the operational effects achieved by the same structure as that of the projector 501 can be obtained.

[0147] Second Embodiment

[0148] Next, Figure 6 A description will be given of the second embodiment of the present invention. In the description of the second embodiment and its modifications, the same content as that of the first embodiment and its modifications is omitted, and the same reference numerals as those of the corresponding structures in the projector 501 are used for the structures identical to those of the projector 501 according to the first embodiment. In the description of the second embodiment and its modifications, only the structures and content different from those already described in the first embodiment and its modifications will be described.

[0149] Although not shown, the projector according to the second embodiment of the present invention is the same as the projector 501 according to the first embodiment, and includes 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 combining member 200, a projection optical system 450, and cooling fans 481, 482, and 483.

[0150] Figure 6 FIG. is an enlarged view of a part of the projector according to 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 toward the -X side along the X direction. In addition, in Figure 2 the substrate 111 is omitted.

[0151] As Figure 6 shown, the liquid crystal panel 371 in the second embodiment is a liquid crystal panel in which the dustproof glass 311 of the liquid crystal panel 351 for blue light LB in the projector 501 according to the first embodiment is removed and the counter substrate 391 is enlarged in the X direction and the Z direction, and has a counter substrate 491, a liquid crystal layer 392, an element substrate 393, and an emission side polarizing plate 361 that are sequentially stacked and arranged from the +Y side toward the -Y side in the Y direction.

[0152] 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 +Y side plate surface of the counter substrate 491 contacts the -Y side end surface, that is, the light emission surface 161b of the light guide member 161. The counter substrate 491 prevents substances such as dust that block the propagation of the blue light LB to the light combining member 200 from entering the pixel forming portion in the liquid crystal panel 371 from the +Y side. The substrate serving as the base of the counter substrate 491 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 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.

[0153] The counter substrate 491 corresponds to the first substrate. The plate surface of the counter substrate 491 is significantly larger than the light emission 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 according to 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.

[0154] The opposed substrate 491 extends more toward the ±Z side and the ±X side than the light emitting surface 161b of the light guide member 161. The cooling fan 481 supplies the cold air W to the extending portion of the opposed substrate 491 that extends toward the -Z side when viewed in the Y direction when viewed in the Y direction. In addition, the cooling fan 481 may also supply the cold air W to the extending portion of the opposed substrate 491 that extends toward any one of the +Z side or the ±X side when viewed in the Y direction when viewed in the Y direction.

[0155] The blue light LB emitted from the light guide member 161 passes through the opposed substrate 491 of the liquid crystal panel 371 and is converted into image light IB by the liquid crystal layer 392 of the image forming region 355. At this time, the opposed 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 the entire end portion toward the +Z side is efficiently cooled by heat exchange and heat dissipation. Since the element substrate 393 and the opposed 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.

[0156] The illumination margin in the blue light emitting portion 101 of the second embodiment is suppressed to the size of the opposed substrate 391 in the Y direction, that is, the thickness of the opposed substrate 391.

[0157] Although not shown, in the projector of the second embodiment, a separate dustproof glass is not provided on the liquid crystal panel for the green light LG, and the plate surface on the -X side of the opposed substrate is in contact with the light emitting surface 162b of the light guide member 162. When viewed in the X direction, the opposed substrate of the liquid crystal panel for the green light LG has extending portions that extend toward the ±Y side and the ±Z side more than the light emitting surface 162b. The cooling fan 482 conveys the cold air to the opposed substrate of the liquid crystal panel for the green light LG and the light guide member 162.

[0158] In the projector of the second embodiment, a separate dustproof glass is not provided on the liquid crystal panel for the red light LR, and the plate surface on the -Y side of the opposed substrate is in contact with the light emitting surface 163b of the light guide member 163. When viewed in the Y direction, the opposed substrate of the liquid crystal panel for the red light LR has extending portions that extend toward the ±X side and the ±Z side more than the light emitting surface 163b. The cooling fan 483 conveys the cold air to the opposed substrate of the liquid crystal panel for the red light LR and the light guide member 163.

[0159] 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 emission surface 161b of the light guide member 161 is in contact with a part of the incident side of the blue light LB in the liquid crystal panel 371 (a part of the light incident side). For example, a part of the incident side of the blue light LB in the liquid crystal panel 371 is a part of the +Y side plate surface of the counter substrate 491 where the blue light LB is incident, and when viewed along the Y direction, it is an area (a part) that includes the center of the +Y side plate surface of the counter substrate 491 and overlaps with the emission surface 161b of the light guide member 161.

[0160] In the projector of the second embodiment, since the emission surface 161b of the light guide member 161 is in contact with a part of the +Y side plate surface of the counter substrate 491 of the liquid crystal panel 371, it is possible to suppress the leakage of the blue light LB to the outside of the light guide member 161 and the liquid crystal panel 371 in the Y direction and on the XZ plane. In addition, in the projector of the second embodiment, it is possible to satisfactorily suppress the illumination margin for the image formation regions 355, 356, and 357. And since no polarizing plate is arranged on the incident side of each of the liquid crystal panels 351, 352, and 353, there is no reduction in light utilization efficiency caused by the polarizing plate on the incident side of the liquid crystal panels 351, 352, and 353. Thus, in the projector of the second embodiment, the blue light LB emitted from the light guide member 161 is efficiently incident on the liquid crystal panel 371, the green light LG emitted from the light guide member 162 is efficiently incident on the liquid crystal panel 372, and the red light LR emitted from the light guide member 163 is efficiently incident on the liquid crystal panel 373. According to the projector 501 of the second embodiment, it is possible to improve the light utilization efficiency of each of the blue light LB, the green light LG, and the red light LR.

[0161] In the projector of the second embodiment, the same operational effects as those achieved by the same structure as the projector 501 of the first embodiment can be obtained.

[0162] In the projector of the second embodiment, the liquid crystal panel 371 has an image formation 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 of the second embodiment, the emission surface 161b of the light guide member 161 is in contact with the counter substrate 491.

[0163] In the projector according to the second embodiment, when viewed along the Y direction in the XY plane of the counter substrate 491 disposed on the +Y side most in the liquid crystal panel 351, the portion overlapping with the light emitting surface 161b of the light guide member 161 contacts 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, light leakage of color light between the light guide member 161 and the counter substrate 491 can be well prevented, and the illumination margin for the image forming region 355 can be suppressed to be small.

[0164] The projector according to the second embodiment further includes a cooling fan 481 that delivers cold air (air) W to the liquid crystal panel 351. In the projector according to the second embodiment, when viewed along the optical axis AX1 of the blue light LB and the Y direction, the planar size of the counter substrate 491, that is, the size on the XY plane, is larger than the planar sizes of the element substrate 393 and the emission side polarizing plate 361, respectively. The cooling fan 481 delivers cold air W to the counter substrate 491.

[0165] In the projector according to the second embodiment, the cold air W from the cooling fan 481 is sent to the extension portion of the counter substrate 491 that protrudes from the element substrate 393 and the emission side polarizing plate 361 when viewed along the Y direction. By the cold air W from the cooling fan 481, mainly the counter substrate 491 is directly cooled, and the light guide member 161 in contact with the counter substrate 491 is indirectly cooled. The element substrate 393 is cooled by the same method as before. As a result, deterioration of the performance of the liquid crystal panel 351 due to irradiation with the blue light LB can be suppressed. According to the projector of the second embodiment, deterioration of the performance of the liquid crystal panel 351 can be effectively suppressed, and the liquid crystal panel 351 can be used for a long time.

[0166] In the projector according to the second embodiment, the cooling fan 481 also delivers cold air W to the light guide member 161.

[0167] In the projector according to the second embodiment, a part of the cold air W from the cooling fan 481 cools the light guide member 161. According to the projector of the second embodiment, 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 received from the dustproof 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 larger surface area than the dustproof glass 311.

[0168] Modification of the second embodiment

[0169] Next, a modified example of the second embodiment of the present invention will be described. Although not shown, in a modified example of the projector of the second embodiment, in the Y direction, an air layer is provided between the +Y side plate surface of the counter substrate 491 of the liquid crystal panel 371 and the -Y side end surface, i.e., the light exit surface 161b, of the light guide member 161 of the blue light emission unit 101. The thickness of the air layer in the Y direction, i.e., the separation distance between the light exit surface 161b and the +Y side plate surface of the counter substrate 491, is 3 μm or less, preferably 1 μm or less.

[0170] The modified example of the projector of the second embodiment includes the following states: the light exit surface 161b and the portion (a part) of the +Y side plate surface of the counter substrate 491 that overlaps the light exit surface 161b at least when viewed in the Y direction respectively have the same flatness and the same fine unevenness in the XZ plane, and the surfaces of each other are in overall contact. The modified example of the projector of the second embodiment further includes the following states: one of the light exit surface 161b and a part of the +Y side plate surface of the counter substrate 491 has a different flatness from the other surface and different fine unevenness in the XZ plane from the other surface, and a deviation occurs in the separation distance in the Y direction between the light exit surface 161b and a part of the +Y side plate surface of the counter substrate 491. In this case, the separation distance is, for example, greater than 0 μm and 3 μm or less, preferably 1 μm or less.

[0171] The modified example of the projector of the second embodiment has 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. In the modified example of the projector of the second embodiment, an air layer of 3 μm or less is provided between the light exit surface 161b of the light guide member 161 and a part (a part on the light incident side) of the liquid crystal panel 371 on the incident side of the blue light LB.

[0172] In a modified example of the projector according to the second embodiment, 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. Therefore, substantially in the same state as when 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, leakage of blue light LB in the Y direction and the XZ plane to the outside of the light guide member 161 and the liquid crystal panel 351 can be suppressed. Further, when image light IB is generated, heat is generated in the liquid crystal panel 371 and the counter substrate 491 is heated. 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. Therefore, substantially in the same state as when 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, heat exchange and heat dissipation between the counter substrate 491 and the light guide member 161 are performed, and the entire end portion of the counter substrate 491 on the -Z side and the like are efficiently cooled. Also, in the modified example of the projector according to the second embodiment, the illumination margins for the respective image forming regions 355, 356, and 357 can be suppressed well. In addition, since no polarizing plate is disposed on the incident side of each of the liquid crystal panels 351, 352, and 353, a reduction in light utilization efficiency caused by the polarizing plate does not occur on the incident side of each of the liquid crystal panels 351, 352, and 353. Thus, in the modified example of the projector according to the second embodiment, blue light LB emitted from the light guide member 161 is efficiently incident on the liquid crystal panel 351, green light LG emitted from the light guide member 162 is efficiently incident on the liquid crystal panel 352, and 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 according to the second embodiment, the light utilization efficiency of each of blue light LB, green light LG, and red light LR can be improved.

[0173] According to the modified example of the projector according to the second embodiment, the effects achieved by the same structure as that of the projector according to the second embodiment can be obtained.

[0174] As described above, the preferred embodiments of the present invention have been described in detail. However, the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims.

[0175] For example, in the above-described embodiment, a three-panel type 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 type projector using linearly polarized light of one color, or a projector using linearly polarized lights of four or more colors and capable of synthesizing a plurality of color lights with each other through a plurality of light combining members.

[0176] Summary of the present disclosure

[0177] The summary of the present disclosure is noted below.

[0178] (Note 1) A projector includes: a first light source that emits linearly polarized first 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 into 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 a cross-sectional area of the first inclined portion increases as it goes 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 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.

[0179] According to the structure of Note 1, leakage of the first light emitted from the first light source between the first light guide member and the first liquid crystal panel is suppressed, and the illumination margin of the image formation region of the first liquid crystal panel is suppressed. It is sufficient not to consider the loss of the first light caused by the polarizing plate on the incident side of the first liquid crystal panel. Therefore, the light utilization efficiency of the first light can be improved.

[0180] (Note 2) In the projector according to Note 1, the linearly polarized first light emitted from the first light source is incident on the first liquid crystal panel in such a manner that the polarization direction does not change between the first light source and the first liquid crystal panel.

[0181] According to the structure of Note 2, changes in the polarization direction of the first light until it is incident on the first liquid crystal panel and rotation of the polarization direction with respect to the first optical axis in a plane orthogonal to the first optical axis are suppressed. Therefore, the loss of the amount of the first light incident on the first liquid crystal panel can be suppressed to a minimum.

[0182] (Note 3) In the projector according to Note 1 or 2, a shape of a cross-section of the first light guide member perpendicular to the first optical axis is rectangular, a shape of the first emission surface is rectangular, and a polarization direction of the linearly polarized first light is in a direction along one of a long side direction and a short side direction of the rectangle.

[0183] According to the structure of Supplementary Note 3, when the first light is incident on the first light guide member, the polarization direction of the first light is along a direction that is preferably the polarization direction of the pixels incident on the first liquid crystal panel. Therefore, it is possible to suppress the loss of the light amount of the first light guided by the first light guide member and incident on the first liquid crystal panel to the minimum, and it is possible to easily control the first light in each pixel of the first liquid crystal panel to generate image light.

[0184] (Supplementary Note 4) The projector according to any one of Supplementary Notes 1 to 3, wherein the first liquid crystal panel has an image forming region in which a plurality of pixels are arranged, and the first liquid crystal panel includes: a first substrate; a second substrate that faces the first substrate across a liquid crystal layer; an incident side dustproof member that is disposed on the light incident side with respect to the first substrate; and an emission side dustproof member that is disposed on the light emission side with respect to the second substrate, and 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.

[0185] According to the structure of Supplementary Note 4, it is possible to suppress the separation distance between the first light guide member and the liquid crystal layer of the first liquid crystal panel to be equal to the sum of the thicknesses of the incident side dustproof member and the first substrate, and to prevent the leakage of the first light between the first light guide member and the incident side dustproof member well, suppress the illumination margin for the image forming region of the first liquid crystal panel to be small, and improve the light utilization efficiency of the first light.

[0186] (Supplementary Note 5) The projector according to Supplementary Note 4, wherein the projector further includes a cooling fan that supplies air to the first liquid crystal panel, and 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, and the cooling fan supplies the air to the incident side dustproof member.

[0187] According to the structure of Supplementary Note 5, the incident side dustproof member of the first liquid crystal panel supplied with air from the cooling fan is cooled, preventing excessive temperature rise and malfunction of the first liquid crystal panel caused by the irradiation of the first light. Therefore, it is possible to effectively suppress the performance deterioration of the first liquid crystal panel and to achieve long-term use of the first liquid crystal panel.

[0188] (Supplementary Note 6) The projector according to Supplementary Note 5, wherein the cooling fan also supplies the air to the first light guide member.

[0189] According to the structure of Supplementary Note 6, the first light guide member having a larger surface area than the incident side dustproof member of the first liquid crystal panel is cooled by a part of the air supplied from the cooling fan. Therefore, it is possible to efficiently dissipate the heat transferred from the first liquid crystal panel.

[0190] (Supplementary Note 7) The projector according to any one of Supplementary Notes 1-3, wherein the first liquid crystal panel has an image forming region in which a plurality of pixels are arranged, and the first liquid crystal panel includes: a first substrate; a second substrate that faces the first substrate with a liquid crystal layer interposed therebetween; and an emission-side dustproof member that is disposed on the light emission side with respect to the second substrate, the first emission surface being in contact with the first substrate, or an air layer being provided between the first emission surface and the first substrate.

[0191] According to the structure of Supplementary Note 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 equal to the thickness of the first substrate, effectively preventing the leakage of the first light between the first light guide member and the incident-side dustproof member, suppressing the illumination margin for the image forming region of the first liquid crystal panel to be small, and improving the light utilization efficiency of the first light.

[0192] (Supplementary Note 8) The projector according to Supplementary Note 7, wherein the projector further includes a cooling fan that supplies air to the first liquid crystal panel, and when viewed along the first optical axis, the planar dimension of the first substrate is larger than the planar dimensions of the second substrate and the emission-side dustproof member, and the cooling fan supplies the air to the first substrate.

[0193] According to the structure of Supplementary Note 8, the first substrate of the first liquid crystal panel supplied with air from the cooling fan is cooled, preventing excessive temperature rise and malfunction of the first liquid crystal panel caused by irradiation with the first light. 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 achieved.

[0194] (Supplementary Note 9) The projector according to Supplementary Note 8, wherein the cooling fan further supplies the air to the first light guide member.

[0195] According to the structure of Supplementary Note 9, 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, so that the heat transferred from the first liquid crystal panel can be efficiently dissipated.

[0196] (Supplementary Note 10) The projector according to any one of Supplementary Notes 1-9, wherein 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, and the first diffusion device is disposed between the first condenser element and the first light guide member.

[0197] According to the structure of Supplementary Note 10, 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, so that the uniformity of the illuminance distribution of the first light emitted from the first light guide member can be improved.

[0198] (Supplementary Note 11) The projector according to any one of Supplementary Notes 1 to 10, wherein the projector further includes: a second light source that emits second light that is linearly polarized in 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 having: 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 the cross-sectional area of the second inclined portion increases as it faces the direction in which the second light is guided, and 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.

[0199] According to the structure of Supplementary Note 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 improved, and the color light including the first light and the second light projected from the projector can be made bright.

Claims

1. A projector comprising: a first light source emitting linearly polarized first light; a first light focusing element for focusing the first light emitted from the first light source; a first light guide member for guiding the first light emitted from the first light focusing element; and a first liquid crystal panel that modulates the first light emitted from the first light guide member, The first light guide member comprises: a first incident surface on which the first light emitted from the first light focusing element is incident; a first emission surface that emits the first light toward the first liquid crystal panel; and a first inclined portion which is inclined relative to a first optical axis of the first light guide member, wherein a cross-sectional area of ​​the first inclined portion increases toward a direction for guiding the first light, The first emission surface of the first light guide member is in contact with a portion 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 portion.

2. The projector according to claim 1, wherein: The linearly polarized first light emitted from the first light source is incident on the first liquid crystal panel in a manner such that a polarization direction does not change between the first light source and the first liquid crystal panel.

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

4. The projector according to claim 1 or 2, wherein: The first liquid crystal panel has an image forming area where a plurality of pixels are arranged. The first liquid crystal panel comprises: 1st substrate; a second substrate, which is opposite to the first substrate via the liquid crystal layer; an incident-side dust-proof member disposed on the light incident side relative to the first substrate; and an emission-side dust-proof component, which is arranged on the light emission side relative to the second substrate, The first emitting surface is in contact with the incident-side dust-proofing member, or the air layer is provided between the first emitting surface and the incident-side dust-proofing member.

5. The projector according to claim 4, wherein: The projector further includes a cooling fan for supplying air to the first liquid crystal panel. The plane size of the incident-side dust-proof component when viewed along the first optical axis is larger than the plane sizes of the first substrate, the second substrate, and the emitting-side dust-proof component. The cooling fan sends the air toward the incident-side dust-proof member.

6. The projector according to claim 5, wherein: The cooling fan further sends the air toward the first light guiding member.

7. The projector according to claim 1 or 2, wherein: The first liquid crystal panel has an image forming area where a plurality of pixels are arranged. The first liquid crystal panel comprises: 1st substrate; a second substrate facing the first substrate with the liquid crystal layer interposed therebetween; and an emission-side dust-proof component, which is arranged on the light emission side relative to the second substrate, The first emitting surface is in contact with the first substrate, or the air layer is provided between the first emitting surface and the first substrate.

8. The projector according to claim 7, wherein: The projector further includes a cooling fan for supplying air to the first liquid crystal panel. The planar dimensions of the first substrate when viewed along the first optical axis are larger than the planar dimensions of the second substrate and the emission-side dust-proof component. The cooling fan sends the air toward the first substrate.

9. The projector according to claim 8, wherein: The cooling fan further sends the air toward the first light guiding member.

10. The projector according to claim 1 or 2, wherein: The projector further includes a first diffusion device having: a first diffusion substrate for diffusing and emitting the incident first light; and a first driving device for rotating the first diffusion substrate. The first diffusion device is arranged between the first light focusing element and the first light guiding member.

11. The projector according to claim 1 or 2, wherein: The projector also has: a second light source that emits a second light having a linear polarization in a second wavelength band different from the first wavelength band of the first light; a second light focusing element for focusing the second light emitted from the second light source; a second light guide member for guiding the second light emitted from the second light focusing element; a second liquid crystal panel that modulates the second light emitted from the second light guide member; and a light combining member for combining the first light and the second light to emit combined light, The second light guide member comprises: a second incident surface on which the second light emitted from the second light focusing element is incident; a second emission surface for emitting the second light toward the second liquid crystal panel; and a second inclined portion which is inclined relative to a second optical axis of the second light guide member, wherein a cross-sectional area of ​​the second inclined portion increases toward a direction for guiding the second light, The second output surface of the second light guide member is in contact with a portion of the second liquid crystal panel on the light incident side, or an air layer of 3 μm or less is provided between the second output surface and the portion.

Images