projector

Abstract

To provide a projector that suppresses the deterioration of a liquid crystal in a light modulation element for modulating a blue light beam.SOLUTION: A projector comprises: a light source; a separation optical system including a first dichroic mirror for separating multicolored light into a first colored light beam as a blue light beam and another colored light beam; a first light modulation element for modulating the first colored light beam; a second light modulation element for modulating the other colored light beam; a reduction optical system for reducing luminous flux width of the first colored light beam modulated by the first light modulation element; a color combining prism; and a projection optical system. An effective area of the first light modulation element is larger than an effective area of the second light modulation element. The separation optical system includes an extension optical system for extending a light path. A first optical axis of the separation optical system and at least part of a second optical axis of the reduction optical system are parallel. The part of the second optical axis is perpendicular to a principal surface of a first surface portion of the color combining prism which the first colored light beam enters. When viewed from a direction orthogonal to the first optical axis and the part of the second optical axis, the extension optical system overlaps the reduction optical system.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] A projector that suppresses the deterioration of the liquid crystal of a liquid crystal device due to light from a light source is described in Patent Document 1. The projector in this document includes a light source, a dichroic mirror that separates the light from the light source into three color lights, three transmissive liquid crystal light valves that modulate the three color lights, a cross dichroic prism that combines the light modulated by the liquid crystal light valves, and a projection lens that projects the combined light. In the projector in this document, of the three liquid crystal light valves, the liquid crystal light valve that modulates blue is more susceptible to deterioration of the liquid crystal due to light than the other liquid crystal light valves that modulate red and green, so the liquid crystal light valve that modulates blue is provided with multiple liquid crystal reservoirs on the outer periphery of the effective display area. As a result, the liquid crystal light valve that modulates blue can increase the total amount of liquid crystal in the liquid crystal light valve more than the other liquid crystal light valves, and therefore can suppress deterioration of the liquid crystal due to light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-38106 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for brighter projectors. However, the projector of Patent Document 1 has a problem in that when the light intensity of the light source is increased to make the projector brighter, it is difficult to suppress deterioration of the liquid crystal in the liquid crystal light valve that modulates blue light. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the projector of the present invention includes a light source, a separation optical system including a first dichroic mirror that separates multi-color light including a first color light from among light emitted from the light source, into a first color light in a first wavelength band including blue light and another color light in a wavelength band longer than the first color light, a first light modulation element that modulates the first color light separated by the first dichroic mirror, a second light modulation element that modulates the other color light separated by the first dichroic mirror, a reduction optical system in which the first light modulation element is disposed on an enlargement-side image forming plane and that reduces, on a reduction-side image forming plane, a light flux width of the first color light modulated by the first light modulation element, and The optical system has a color synthesis prism that emits a synthetic light obtained by synthesizing the other color light modulated by the second light modulation element, and a projection optical system that projects the synthetic light emitted from the color synthesis prism, wherein the effective area of ​​the first light modulation element is larger than the effective area of ​​the second light modulation element, the separation optical system includes an extension optical system that extends an optical path, a first optical axis of the separation optical system and at least a portion of the second optical axis of the reduction optical system are parallel, the portion of the second optical axis is perpendicular to the main surface of the first surface of the color synthesis prism where the first color light is incident, and the extension optical system overlaps with the reduction optical system when viewed from a direction perpendicular to the first optical axis and the portion of the second optical axis. [Brief description of the drawings]

[0006] [Figure 1] 1 is a schematic diagram of a main part of a projector according to a first embodiment. [Diagram 2] FIG. 11 is a schematic diagram of a main part of a projector according to a second embodiment. [Diagram 3] FIG. 11 is a schematic diagram of a main part of a projector according to a third embodiment. [Figure 4] FIG. 11 is a schematic diagram of a main part of a projector according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a projector according to an embodiment of the invention will be described with reference to the drawings.

[0008] [Embodiment 1] Fig. 1 is a schematic diagram of a main part of a projector 100 of the embodiment 1. As shown in Fig. 1, the projector 100 includes a light source 1, an illumination optical system 2 that homogenizes multi-color light from the light source 1, a separation optical system 3 that separates light emitted from the illumination optical system 2 into each color light, a plurality of light modulation elements 7 that modulate each color light separated by the separation optical system 3 to form a projection image, a reduction optical system 6 that reduces the light beam width of the color light modulated by one of the plurality of light modulation elements 7, a color synthesis prism 8 that outputs a synthetic light obtained by synthesizing each color light modulated by the light modulation element 7, a projection optical system 9 that projects the synthetic light output from the color synthesis prism 8, and a control unit 10 that controls the light modulation elements 7.

[0009] For convenience, in the following description, the three mutually orthogonal axes are referred to as the X-axis, Y-axis, and Z-axis. The direction along the first optical axis N of the separation optical system 3 is referred to as the X-axis direction. In the X-axis direction, the direction in which the output light from the illumination optical system 2 is output is referred to as the first direction X1, and the opposite direction is referred to as the second direction X2. In the Y-axis direction, the direction in which the combined light is output from the color combining prism 8 is referred to as the third direction Y1, and the opposite direction is referred to as the fourth direction Y2.

[0010] The light source 1 emits multi-color light. The light source 1 is, for example, an extra-high pressure mercury lamp, a solid-state light source, or the like. In this embodiment, the light source 1 emits white light, which is multi-color light, as the emitted light LD. In this embodiment, the light amounts of the blue light, the green light, and the red light contained in the emitted light LD are equal. Note that the light amounts of the blue light, the green light, and the red light contained in the emitted light LD may be different.

[0011] The illumination optical system 2 includes a multi-lens 21, a polarizing beam splitter 22, a multi-lens 23, and a relay lens 24. The multi-lens 21 splits the output light LD from the light source 1 into multiple light beams. The polarizing beam splitter 22 converts the polarization direction of the output light LD output from the multi-lens 21. The multi-lens 23 focuses the output light LD output from the polarizing beam splitter 22 in the vicinity of the relay lens 24. The relay lens 24 magnifies the output light LD incident from the multi-lens 23 and outputs it toward the separation optical system 3.

[0012] The separation optical system 3 includes, in order in the first direction X1, a second dichroic mirror 32, a first dichroic mirror 31, and an extension optical system 30. The second dichroic mirror 32, the first dichroic mirror 31, and the extension optical system 30 are arranged along a first optical axis N of the separation optical system 3. The second dichroic mirror 32 separates the output light LD into a third color light LR and a multi-color light LC. The second dichroic mirror 32 reflects the third color light LR in the third direction Y1 and transmits the multi-color light LC in the first direction X1. The first dichroic mirror 31 separates the multi-color light LC into a first color light LB and a second color light LG (another color light). The first dichroic mirror 31 reflects the second color light LG in the third direction Y1 and transmits the first color light LB in the first direction X1. In this embodiment, the first colored light LB is a first wavelength band including blue light. The second colored light LG is a second wavelength band including green. The third colored light LR is a third wavelength band including red. The first wavelength band is, for example, 420 nm to 500 nm. The second wavelength band is, for example, 500 nm to 600 nm. The third wavelength band is, for example, 600 nm to 680 nm. The wavelength band of the multi-colored light LC is, for example, 420 nm to 600 nm.

[0013] The extension optical system 30 extends the optical path of the separation optical system 3 in a first direction X1. The extension optical system 30 includes a plurality of lenses 36. The plurality of lenses 36 are arranged along a first optical axis N of the separation optical system 3. The extension optical system 30 is arranged between a first dichroic mirror 31 and a first light modulation element 71 described later.

[0014] Here, a reflecting mirror 13 that reflects the third color light LR separated by the second dichroic mirror 32 toward the first direction X1 is disposed in the third direction Y1 of the second dichroic mirror 32. Lenses 11 are disposed between the second dichroic mirror 32 and the reflecting mirror 13, and between the second dichroic mirror 32 and the first dichroic mirror 31. Lenses 12 are disposed in the first direction X1 of the reflecting mirror 13 and in the third direction Y1 of the first dichroic mirror 31. The lenses 11 and 12 focus the second color light LG and the third color light LR separated by the separation optical system 3 near the light modulation element 7.

[0015] The light modulation element 7 is a liquid crystal panel. The light modulation element 7 includes a first light modulation element 71 that modulates the first color light LB, a third light modulation element 72 that modulates the second color light LG, and a fourth light modulation element 73 that modulates the third color light LR. The first light modulation element 71, the third light modulation element 72, and the fourth light modulation element 73 each include an incident side polarizing plate 75 and an exit side polarizing plate 76. The third light modulation element 72 and the fourth light modulation element 73 correspond to the "second light modulation element" of the present invention.

[0016] The first light modulation element 71 is disposed in the first direction X1 of the extension optical system 30. The optical axis N1 of the first light modulation element 71 coincides with the first optical axis N. The third light modulation element 72 is disposed at a position facing the second surface 82 of the color synthesis prism 8. The fourth light modulation element 73 is disposed at a position facing the third surface 83 of the color synthesis prism 8.

[0017] The effective area of ​​the first light modulation element 71 is larger than those of the third light modulation element 72 and the fourth light modulation element 73. Regarding the diagonal dimension of the effective area (effective display region) of the light modulation element in this embodiment, the first light modulation element 71 is a 1.03-inch liquid crystal panel, and the third light modulation element 72 and the fourth light modulation element 73 are 0.67-inch liquid crystal panels. In this embodiment, the first light modulation element 71, the third light modulation element 72, and the fourth light modulation element 73 have a display resolution of WUXGA (1920 pixels in the horizontal direction, 1200 pixels in the vertical direction), as an example.

[0018] The reduction optical system 6 has the first light modulation element 71 disposed on the enlargement-side imaging surface 60A of the reduction optical system 6, and reduces the light beam width of the first color light LB modulated by the first light modulation element 71 on the reduction-side imaging surface 60B. In this embodiment, the reduction optical system 6 reduces the light beam width of the first color light LB modulated by the first light modulation element 71 from 1.03 inches to 0.67 inches on the reduction-side imaging surface 60B. The reduction-side imaging surface 60B is disposed at a position facing the first surface 81 of the color synthesis prism 8. The distance between the reduction-side imaging surface 60B and the first surface 81 of the color synthesis prism 8 is the same as the distance between the third light modulation element 72 and the second surface 82 of the color synthesis prism 8. In addition, the distance between the reduction-side imaging surface 60B and the first surface 81 of the color synthesis prism 8 is the same as the distance between the fourth light modulation element 73 and the third surface 83 of the color synthesis prism 8.

[0019] Here, the projector 100 has a polarizing plate 5 disposed between the reduction-side imaging surface 60B and the first surface 81. The polarizing plate 5 and the exit-side polarizing plate 76 of the first light modulation element 71 transmit linearly polarized components in the same direction among the polarized components contained in the first color light LB. That is, when the exit-side polarizing plate 76 of the first light modulation element 71 transmits the S-polarized light of the first color light LB, the polarizing plate 5 transmits the S-polarized light, and when the exit-side polarizing plate 76 of the first light modulation element 71 transmits the P-polarized light of the first color light LB, the polarizing plate 5 transmits the P-polarized light.

[0020] The color synthesis prism 8 has a first surface 81 on which the first color light LB is incident, a second surface 82 on which the second color light LG is incident, a third surface 83 on which the third color light LR is incident, and a fourth surface 84 from which the synthesized light LE is emitted. The first surface 81 and the third surface 83 face each other in the X-axis direction. The second surface 82 and the fourth surface 84 face each other in the Y-axis direction. The color synthesis prism 8 emits synthesized light LE, which is obtained by combining the first color light LB, the light beam width of which has been reduced by the reduction optical system 6, the second color light LG, which has been modulated by the third light modulation element 72, and the third color light LR, which has been modulated by the fourth light modulation element 73, from the fourth surface 84 in the third direction Y1. Here, the beam width of the first color light LB incident on the first surface 81 of the color synthesis prism 8 is the same as the beam width of the second color light LG incident on the second surface 82 of the color synthesis prism 8 and the beam width of the third color light LR incident on the third surface 83 of the color synthesis prism 8.

[0021] The projection optical system 9 projects the combined light LE emitted from the color combining prism 8 onto a screen. The projection optical system 9 includes a plurality of lenses. The control unit 10 operates the light modulation element 7 based on an external image signal such as a video signal.

[0022] (Details of the reduction optical system) 1, the reduction optical system 6 includes, in order from the enlargement side to the reduction side, a first lens group G1 that is made up of multiple lenses and has positive power, a second lens group G2 that has one or two lenses, at least one of which is a negative lens that has negative power, and a third lens group G3 that is made up of multiple lenses and has positive power. The reduction optical system 6 includes an aperture 65 between the second lens group G2 and the third lens group G3. The first lens group G1, the second lens group G2, and the third lens group G3 are arranged along a second optical axis M of the reduction optical system 6.

[0023] The number of lenses in the first lens group G1 is the same as the number of lenses in the third lens group G3. More specifically, the first lens group G1 is made up of four lenses, lens L1 to lens L4. The third lens group G3 is made up of four lenses, lens L7 to lens L10.

[0024] The second lens group G2 is composed of two lenses, a lens L5 and a lens L6. At least one of the lenses L5 and L6 is a negative lens. The lenses L2 to L10 are disposed in a portion M1 of the second optical axis M that extends in the X-axis direction. The lens L1 is disposed in another portion M2 of the second optical axis M that extends in the Y-axis direction.

[0025] The reduction optical system 6 includes a first reflecting mirror 61 that reflects the first color light LB modulated by the first light modulation element 71 in the third direction Y1, and a second reflecting mirror 62 that reflects the first color light LB reflected by the first reflecting mirror 61 in the second direction X2. The first reflecting mirror 61 is disposed in the fourth direction Y2 of the lens L1. The second reflecting mirror 62 is disposed between the lens L1 and the lens L2.

[0026] Both sides of the reduction optical system 6, that is, the enlargement side of the first lens group G1 and the reduction side of the third lens group G3, are telecentric. The enlargement side of the first lens group G1 is telecentric when the central ray of each light beam passing between the first lens group G1 and the enlargement side image forming surface 60A is parallel to the second optical axis M or approximately parallel to the second optical axis M. The reduction side of the third lens group G3 is telecentric when the central ray of each light beam passing between the third lens group G3 and the reduction side image forming surface 60B is parallel to the second optical axis M or approximately parallel to the second optical axis M. In this embodiment, the angle between the central ray of each light beam and the second optical axis M is within ±5°.

[0027] The first optical axis N of the separation optical system 3 and at least a portion M1 of the second optical axis M of the reduction optical system 6 are parallel to each other. The portion M1 of the second optical axis M is perpendicular to the principal surface of the first surface portion 81 of the color synthesis prism 8 onto which the first color light LB is incident. When viewed from a direction perpendicular to the first optical axis N and the portion M1 of the second optical axis M, the extension optical system 30 overlaps with the reduction optical system 6.

[0028] In the Y-axis direction, the distance A between the first optical axis N and the part M1 of the second optical axis is the same as the distance B between the first optical axis N and the optical axis O of the third color light LR incident on the third surface 83.

[0029] (Action and effect) The projector 100 of this embodiment includes a light source 1, a separation optical system 3 including a first dichroic mirror 31 that separates a multi-color light LC including a first color light LB from the output light LD emitted from the light source 1 into a first color light LB in a first wavelength band including blue light and another color light in a wavelength band longer than the first color light LB, a first light modulation element 71 that modulates the first color light LB separated by the first dichroic mirror 31, and a second light modulation element 72 that modulates the first color light LB separated by the first dichroic mirror 31. The optical system includes a second light modulation element that modulates the first color light LB, a reduction optical system 6 in which a first light modulation element 71 is disposed on an enlargement-side imaging surface 60A and that reduces the light beam width of the first color light LB modulated by the first light modulation element 71 on a reduction-side imaging surface 60B, a color synthesis prism 8 that outputs a synthesized light LE obtained by synthesizing the first color light LB whose light beam width has been reduced by the reduction optical system 6 and the other color light modulated by the second light modulation element, and a projection optical system 9 that projects the synthesized light LE output from the color synthesis prism 8. The effective area of ​​the first light modulation element 71 is larger than the effective area of ​​the second light modulation element. The separation optical system 3 includes an extension optical system 30 that extends the optical path. The first optical axis N of the separation optical system 3 and at least a portion M1 of the second optical axis M of the reduction optical system 6 are parallel. The portion M1 of the second optical axis is perpendicular to the main surface of the first surface portion 81 of the color synthesis prism 8 on which the first color light LB is incident. When viewed from the Y-axis direction, the extension optical system 30 overlaps with the reduction optical system 6.

[0030] According to this embodiment, since the effective area of ​​the first light modulation element 71 is larger than that of the second light modulation element, the illuminance irradiated on the first light modulation element 71 can be made smaller than that on the second light modulation element. This makes it possible to prevent the liquid crystal of the first light modulation element 71 from being deteriorated by light even if the light source 1 is made brighter.

[0031] In addition, since the reduction optical system 6 can reduce the beam width of the first color light LB modulated by the first light modulation element 71 at the reduction side imaging surface 60B, the beam width of each color light incident on the color synthesis prism 8 can be made the same size even if the effective area of ​​the first light modulation element 71 is larger than the effective area of ​​the third light modulation element 72.

[0032] In addition, since the separation optical system 3 includes the extension optical system 30 that extends the optical path, the separation optical system 3 and the reduction optical system 6 can be overlapped in the Y-axis direction. This makes it possible to make the width of the projector 100 compact in the Y-axis direction.

[0033] In this embodiment, the first dichroic mirror 31 transmits the first color light LB in the first direction X1. The first light modulation element 71 is located in the first direction X1 of the first dichroic mirror 31. The reduction optical system 6 includes a first reflecting mirror 61 that reflects the first color light LB modulated by the first light modulation element 71 in the third direction Y1, and a second reflecting mirror 62 that reflects the first color light LB reflected by the first reflecting mirror 61 in the second direction X2 opposite to the first direction X1. The extension optical system 30 is disposed between the first dichroic mirror 31 and the first light modulation element 71. Therefore, since the reduction optical system 6 includes the first reflecting mirror 61 and the second reflecting mirror 62, the reduction optical system 6 can bend the first color light LB emitted from the first light modulation element 71 in the first direction X1 in the second direction X2. This allows the separation optical system 3 and the reduction optical system 6 to overlap in the Y-axis direction.

[0034] The projector 100 of this embodiment has a polarizing plate 5 disposed between the reduction-side imaging surface 60B and the first surface 81. Therefore, even if the polarization direction of the first colored light LB emitted from the first light modulation element 71 is disturbed when the first colored light LB passes through the reduction optical system 6, the polarizing plate 5 can compensate for the polarization direction of the first colored light LB. This makes it possible to suppress a decrease in the contrast of the first colored light LB incident on the color synthesis prism 8.

[0035] In this embodiment, the separation optical system 3 includes a second dichroic mirror 32 that separates the output light LD into a third color light LR in a third wavelength band including red and a multi-color light LC. The first dichroic mirror 31 separates the multi-color light LC separated by the second dichroic mirror 32 into a first color light LB and a second color light LG in a second wavelength band including green, which is another color light. The second light modulation element includes a third light modulation element 72 that modulates the second color light LG separated by the first dichroic mirror 31, and a fourth light modulation element 73 that modulates the third color light LR separated by the second dichroic mirror 32. The color synthesis prism 8 emits a synthesized light LE obtained by synthesizing the first color light LB whose light beam width has been reduced by the reduction optical system 6, the second color light LG modulated by the third light modulation element 72, and the third color light LR modulated by the fourth light modulation element 73. In this way, the projector 100 can project full-color composite light LE.

[0036] The luminous flux width of the first colored light LB incident on the first surface 81 of the color combining prism 8 is the same as the luminous flux width of the second colored light LG incident on the second surface 82 of the color combining prism 8 and the luminous flux width of the third colored light LR incident on the third surface 83 of the color combining prism 8. Therefore, the color combining prism 8 can easily combine the respective colored lights into one combined light LE.

[0037] In this embodiment, the first surface 81 and the third surface 83 face each other in the X-axis direction, that is, in the direction along a portion M1 of the second optical axis. In the Y-axis direction, a distance A between the first optical axis N and the portion M1 of the second optical axis is the same as a distance B between the first optical axis N and the optical axis O of the third color light LR incident on the third surface 83. Therefore, it is possible to prevent the projector from becoming large in size in the Y-axis direction.

[0038] In this embodiment, the reduction optical system 6 includes, in order from the enlargement side to the reduction side, a first lens group G1 that is made up of multiple lenses and has positive power, a second lens group G2 that has two lenses, at least one of which is a negative lens and has negative power, and a third lens group G3 that is made up of multiple lenses and has positive power. The number of lenses in the first lens group G1 is the same as the number of lenses in the third lens group G3. Both sides of the reduction optical system 6 are telecentric. Therefore, since the number of lenses in the first lens group G1 and the third lens group G3 that sandwich the second lens group G2 are the same, various aberrations generated in the first lens group G1 can be canceled by the third lens group G3. In addition, compared to a reduction optical system 6 that is not telecentric on both sides, the installation accuracy for the first light modulation element 71 is not strict when the reduction optical system 6 is incorporated into the projector 100. Furthermore, since the first color light LB traveling from the reduction-side image-forming surface 60B toward the color synthesis prism 8 becomes parallel light, the occurrence of various aberrations occurring in the reduction optical system 6 can be easily suppressed.

[0039] In addition, since the reduction optical system 6 is composed of multiple lenses, it is easy to accommodate multiple lenses in the lens barrel. Therefore, when multiple lenses are accommodated in the lens barrel, it is easy to incorporate the reduction optical system 6 into the projector body, and variations in the assembly of the reduction optical system 6 can be suppressed.

[0040] The second reflecting mirror 62 is disposed between the lenses L1 and L2 of the first lens group G1. In this way, the lens L1 can be disposed along the portion M2 of the second optical axis that is perpendicular to the portion M1, so that the length of the reduction optical system 6 in the X-axis direction can be made more compact than when the lenses of the reduction optical system 6 are disposed linearly.

[0041] [Embodiment 2] 2 is a schematic diagram of a main part of a projector 100A of embodiment 2. The projector 100A of embodiment 2 differs from the projector 100 of embodiment 1 in the configurations of a separation optical system 3 and a reduction optical system 6. Therefore, in embodiment 2, the same configurations as those of embodiment 1 are denoted by the same reference numerals, and descriptions thereof may be omitted.

[0042] The separation optical system 3 includes a first dichroic mirror 31, an extension optical system 30, and a second dichroic mirror 32, arranged in this order in the first direction X1. The first dichroic mirror 31, the extension optical system 30, and the second dichroic mirror 32 are arranged along a first optical axis N of the separation optical system 3. The first dichroic mirror 31 separates the output light LD (multi-color light) into a first color light LB and another color light LM. The first dichroic mirror 31 reflects the first color light LB in the third direction Y1 and transmits the other color light LM in the first direction X1. The second dichroic mirror 32 separates the other color light LM into a second color light LG and a third color light LR. The second dichroic mirror 32 reflects the second color light LG in the third direction Y1 and transmits the third color light LR in the first direction X1. In this embodiment, the first colored light LB is a first wavelength band including blue light. The second colored light LG is a second wavelength band including green. The third colored light LR is a third wavelength band including red. The first wavelength band is, for example, 420 nm to 500 nm. The second wavelength band is, for example, 500 nm to 600 nm. The third wavelength band is, for example, 600 nm to 680 nm. The wavelength band of the other colored light LM is, for example, 500 nm to 680 nm.

[0043] The extension optical system 30 includes a plurality of lenses 36. The plurality of lenses 36 are arranged along the first optical axis N of the separation optical system 3. The extension optical system 30 is arranged between the first dichroic mirror 31 and the second dichroic mirror 32.

[0044] Here, a reflecting mirror 16 is disposed in the first direction X1 of the second dichroic mirror 32, which reflects the third color light LR separated by the second dichroic mirror 32 in the third direction Y1. A reflecting mirror 17 is disposed in the third direction Y1 of the reflecting mirror 16, which reflects the third color light LR reflected by the reflecting mirror 16 in the second direction X2. Lenses 12 are disposed in the third direction Y1 of the second dichroic mirror 32, the third direction Y1 of the reflecting mirror 16, and the second direction X2 of the reflecting mirror 17. The lens 12 collects the second color light LG and the third color light LR separated by the separation optical system 3 near the light modulation element 7.

[0045] The first light modulation element 71 is disposed in the third direction Y1 of the first dichroic mirror 31. The optical axis N1 of the first light modulation element 71 extends in the direction along the Y axis. The third light modulation element 72 is disposed at a position facing the second surface 82 of the color synthesis prism 8. The fourth light modulation element 73 is disposed at a position facing the third surface 83 of the color synthesis prism 8.

[0046] The effective area of ​​the first light modulation element 71 is larger than those of the third light modulation element 72 and the fourth light modulation element 73. Regarding the diagonal dimension of the effective area (effective display region) of the optical element in this embodiment, the first light modulation element 71 is a 1.03-inch liquid crystal panel, and the third light modulation element 72 and the fourth light modulation element 73 are 0.67-inch liquid crystal panels. The first light modulation element 71, the third light modulation element 72, and the fourth light modulation element 73 have a display resolution of WUXGA (1920 pixels in the horizontal direction, 1200 pixels in the vertical direction), as an example.

[0047] Here, the projector 100A has a polarizing plate 5 disposed between the reduction-side imaging surface 60B and the first surface 81. The polarizing plate 5 and the output-side polarizing plate 76 of the first light modulation element 71 transmit linearly polarized components in the same direction among the polarized components contained in the first color light LB.

[0048] The beam width of the first color light LB incident on the first surface 81 of the color synthesis prism 8 is the same as the beam width of the second color light LG incident on the second surface 82 of the color synthesis prism 8 and the beam width of the third color light LR incident on the third surface 83 of the color synthesis prism 8.

[0049] (Details of the reduction optical system) 2, the reduction optical system 6 includes, in order from the enlargement side to the reduction side, a first lens group G1 that is made up of multiple lenses and has positive power, a second lens group G2 that has one or two lenses, at least one of which is a negative lens that has negative power, and a third lens group G3 that is made up of multiple lenses and has positive power. The reduction optical system 6 includes an aperture 65 between the second lens group G2 and the third lens group G3. The first lens group G1, the second lens group G2, and the third lens group G3 are arranged along a second optical axis M of the reduction optical system 6.

[0050] The first lens group G1 consists of four lenses, lens L1 to lens L4. The second lens group G2 consists of two lenses, lens L5 and lens L6. At least one of the lenses L5 and L6 is a negative lens. The third lens group G3 consists of four lenses, lens L7 to lens L10. Lenses L2 to L10 are disposed in a portion M1 extending in the X-axis direction of the second optical axis M. Lens L1 is disposed in another portion M2 extending in the Y-axis direction of the second optical axis M.

[0051] The reduction optical system 6 includes a first reflecting mirror 61 that reflects, in a first direction X1, the first color light LB modulated by the first light modulation element 71. The first reflecting mirror 61 is disposed between the lens L1 and the lens L2.

[0052] The enlargement side of the first lens group G1 and the reduction side of the third lens group G3 are each telecentric.

[0053] The first optical axis N of the separation optical system 3 and at least a portion M1 of the second optical axis M of the reduction optical system 6 are parallel to each other. The portion M1 of the second optical axis M is perpendicular to the principal surface of the first surface portion 81 of the color synthesis prism 8 onto which the first color light LB is incident. When viewed from a direction perpendicular to the first optical axis N and the portion M1 of the second optical axis M, the extension optical system 30 overlaps with the reduction optical system 6.

[0054] In the Y-axis direction, the distance A between the first optical axis N and the part M1 of the second optical axis is the same as the distance B between the first optical axis N and the optical axis O of the third color light LR incident on the third surface 83.

[0055] (Action and effect) In this embodiment, the first dichroic mirror 31 reflects the first color light LB in the third direction Y1. The first light modulation element 71 is located in the third direction Y1 of the first dichroic mirror 31. The reduction optical system 6 includes a first reflecting mirror 61 that reflects the first color light LB modulated by the first light modulation element 71 in the first direction X1. The extension optical system 30 is disposed in the first direction X1 of the first dichroic mirror 31. Therefore, since the reduction optical system 6 includes the first reflecting mirror 61, the separation optical system 3 and the reduction optical system 6 can be overlapped in the Y-axis direction.

[0056] In this embodiment, the separation optical system 3 includes a second dichroic mirror 32 that separates the other color light LM separated by the first dichroic mirror 31 into a second color light LG in a second wavelength band including green and a third color light LR in a third wavelength band including red. The second light modulation element includes a third light modulation element 72 that modulates the second color light LG separated by the second dichroic mirror 32, and a fourth light modulation element 73 that modulates the third color light LR separated by the second dichroic mirror 32. The color synthesis prism 8 emits a synthetic light LE obtained by synthesizing the first color light LB whose light beam width has been reduced by the reduction optical system 6, the second color light LG modulated by the third light modulation element 72, and the third color light LR modulated by the fourth light modulation element 73. In this manner, the projector 100 can project a full-color synthetic light LE.

[0057] The first reflecting mirror 61 is disposed between the lenses L1 and L2 of the first lens group G1. In this way, the lens L1 can be disposed along the portion M2 of the second optical axis that is perpendicular to the portion M1, so that the length of the reduction optical system 6 in the X-axis direction can be made more compact than when the lenses of the reduction optical system 6 are disposed linearly.

[0058] In the second embodiment, the same functions and effects as those of the first embodiment can be obtained with respect to the same configuration as that of the first embodiment.

[0059] [Embodiment 3] 3 is a schematic diagram of a main part of a projector 100B of embodiment 3. The projector 100B of embodiment 3 differs from the projector 100 of embodiment 1 in the configuration of the reduction optical system 6. Therefore, in embodiment 3, the same configurations as those in embodiment 1 are denoted by the same reference numerals, and descriptions thereof may be omitted.

[0060] The projector 100B has a first reflecting mirror 18 that reflects the first color light LB transmitted by the first dichroic mirror 31 in the first direction X1, in a third direction Y1, and a second reflecting mirror 19 that reflects the first color light LB reflected by the first reflecting mirror 18, in a second direction X2. The first reflecting mirror 18 is disposed in the first direction X1 of the extension optical system 30. The second reflecting mirror 19 is disposed in the third direction Y1 of the first reflecting mirror 18.

[0061] The first light modulation element 71 is disposed in the second direction X2 of the second reflecting mirror 19. The optical axis N1 of the first light modulation element 71 extends in the direction along the X-axis. The third light modulation element 72 is disposed at a position facing the second surface 82 of the color synthesis prism 8. The fourth light modulation element 73 is disposed at a position facing the third surface 83 of the color synthesis prism 8.

[0062] The effective area of ​​the first light modulation element 71 is larger than those of the third light modulation element 72 and the fourth light modulation element 73. Regarding the diagonal dimension of the effective area (effective display region) of the light modulation element of this embodiment, the first light modulation element 71 is a 1.03-inch liquid crystal panel, and the third light modulation element 72 and the fourth light modulation element 73 are 0.67-inch liquid crystal panels. The first light modulation element 71, the third light modulation element 72, and the fourth light modulation element 73 have a display resolution of WUXGA (1920 pixels horizontally and 1200 pixels vertically), as an example.

[0063] The projector 100B has a polarizing plate 5 disposed between the reduction-side imaging surface 60B and the first surface 81. The polarizing plate 5 and the output-side polarizing plate 76 of the first light modulation element 71 transmit linearly polarized components in the same direction among the polarized components contained in the first color light LB.

[0064] The beam width of the first color light LB incident on the first surface 81 of the color synthesis prism 8 is the same as the beam width of the second color light LG incident on the second surface 82 of the color synthesis prism 8 and the beam width of the third color light LR incident on the third surface 83 of the color synthesis prism 8.

[0065] (Details of the reduction optical system) 3, the reduction optical system 6 includes, in order from the enlargement side to the reduction side, a first lens group G1 that is made up of multiple lenses and has positive power, a second lens group G2 that has one or two lenses, at least one of which is a negative lens that has negative power, and a third lens group G3 that is made up of multiple lenses and has positive power. The reduction optical system 6 includes an aperture 65 between the second lens group G2 and the third lens group G3. The first lens group G1, the second lens group G2, and the third lens group G3 are arranged along a second optical axis M of the reduction optical system 6.

[0066] The first lens group G1 consists of four lenses, lens L1 to lens L4. The second lens group G2 consists of two lenses, lens L5 and lens L6. At least one of the lenses L5 and L6 is a negative lens. The third lens group G3 consists of four lenses, lens L7 to lens L10. The second optical axis M extends linearly along the X-axis, including a portion M1 that extends in the X-axis direction of the second optical axis M. Lenses L1 to L10 are disposed on the second optical axis M.

[0067] The enlargement side of the first lens group G1 and the reduction side of the third lens group G3 are each telecentric.

[0068] The first optical axis N of the separation optical system 3 and the second optical axis M of the reduction optical system 6 are parallel to each other. The second optical axis M is perpendicular to the main surface of the first surface portion 81 of the color synthesis prism 8 onto which the first color light LB is incident. When viewed from a direction perpendicular to the first optical axis N and the second optical axis M, the extension optical system 30 overlaps with the reduction optical system 6.

[0069] In the Y-axis direction, the distance A between the first optical axis N and the second optical axis M is the same as the distance B between the first optical axis N and the optical axis O of the third color light LR incident on the third surface 83.

[0070] (Action and effect) In this embodiment, the first dichroic mirror 31 transmits the first color light LB in the first direction X1. The projector 100B has a first reflecting mirror 18 that reflects the first color light LB transmitted by the first dichroic mirror 31 in a third direction Y1, and a second reflecting mirror 19 that reflects the first color light LB reflected by the first reflecting mirror 18 in a second direction X2 opposite to the first direction X1. The first light modulation element 71 is located in the second direction X2 of the second reflecting mirror 19. The extension optical system 30 is disposed between the first dichroic mirror 31 and the first reflecting mirror 18. The second optical axis M extends linearly. Therefore, since the projector 100B includes the first reflecting mirror 18 and the second reflecting mirror 19, the separation optical system 3 and the reduction optical system 6 can be overlapped in the Y-axis direction. In this case, since the second optical axis M of the reduction optical system 6 extends linearly, it is easy to dispose the reduction optical system 6.

[0071] In the third embodiment, the same configuration as in the first embodiment can provide the same effects as in the first embodiment.

[0072] [Embodiment 4] 4 is a schematic diagram of a main part of a projector 100C of embodiment 4. The projector 100C of embodiment 4 differs from the projector 100A of embodiment 2 in the configuration of the reduction optical system 6. Therefore, in embodiment 4, the same configurations as those in embodiment 1 may be assigned the same reference numerals and descriptions thereof may be omitted.

[0073] The projector 100C has a first reflecting mirror 18 that reflects, in the first direction X1, the first color light LB reflected in the third direction Y1 by the first dichroic mirror 31. The first reflecting mirror 18 is disposed in the third direction Y1 of the first dichroic mirror 31.

[0074] The first light modulation element 71 is disposed in the first direction X1 of the first reflecting mirror 18. The optical axis N1 of the first light modulation element 71 extends in the direction along the X-axis. The third light modulation element 72 is disposed at a position facing the second surface 82 of the color synthesis prism 8. The fourth light modulation element 73 is disposed at a position facing the third surface 83 of the color synthesis prism 8.

[0075] The effective area of ​​the first light modulation element 71 is larger than those of the third light modulation element 72 and the fourth light modulation element 73. Regarding the diagonal dimension of the effective area (effective display region) of the light modulation element of this embodiment, the first light modulation element 71 is a 1.03-inch liquid crystal panel, and the third light modulation element 72 and the fourth light modulation element 73 are 0.67-inch liquid crystal panels. As an example, the display resolution of the first light modulation element 71, the third light modulation element 72, and the fourth light modulation element 73 is WUXGA (1920 pixels horizontally and 1200 pixels vertically).

[0076] Here, the projector 100C has a polarizing plate 5 disposed between the reduction-side imaging surface 60B and the first surface 81. The polarizing plate 5 and the output-side polarizing plate 76 of the first light modulation element 71 transmit linearly polarized components in the same direction among the polarized components contained in the first color light LB.

[0077] The beam width of the first color light LB incident on the first surface 81 of the color synthesis prism 8 is the same as the beam width of the second color light LG incident on the second surface 82 of the color synthesis prism 8 and the beam width of the third color light LR incident on the third surface 83 of the color synthesis prism 8.

[0078] (Details of the reduction optical system) 4, the reduction optical system 6 includes, in order from the enlargement side to the reduction side, a first lens group G1 that is made up of multiple lenses and has positive power, a second lens group G2 that has one or two lenses, at least one of which is a negative lens that has negative power, and a third lens group G3 that is made up of multiple lenses and has positive power. The reduction optical system 6 includes an aperture 65 between the second lens group G2 and the third lens group G3. The first lens group G1, the second lens group G2, and the third lens group G3 are arranged along a second optical axis M of the reduction optical system 6.

[0079] The first lens group G1 consists of four lenses, lens L1 to lens L4. The second lens group G2 consists of two lenses, lens L5 and lens L6. At least one of the lenses L5 and L6 is a negative lens. The third lens group G3 consists of four lenses, lens L7 to lens L10. The second optical axis M extends linearly along the X-axis, including a portion M1 that extends in the X-axis direction of the second optical axis M. Lenses L1 to L10 are disposed on the second optical axis M.

[0080] The enlargement side of the first lens group G1 and the reduction side of the third lens group G3 are each telecentric.

[0081] The first optical axis N of the separation optical system 3 and the second optical axis M of the reduction optical system 6 are parallel to each other. The second optical axis M is perpendicular to the main surface of the first surface portion 81 of the color synthesis prism 8 onto which the first color light LB is incident. When viewed from a direction perpendicular to the first optical axis N and the second optical axis M, the extension optical system 30 overlaps with the reduction optical system 6.

[0082] In the Y-axis direction, the distance A between the first optical axis N and the second optical axis M is the same as the distance B between the first optical axis N and the optical axis O of the third color light LR incident on the third surface 83.

[0083] (Action and effect) In this embodiment, the first dichroic mirror 31 reflects the first color light LB in the third direction Y1. The projector 100C has a first reflecting mirror 18 that reflects the first color light LB reflected by the first dichroic mirror 31 in the first direction X1. The extension optical system 30 is disposed in the first direction X1 of the first dichroic mirror 31. The second optical axis M extends linearly. Therefore, since the projector 100C includes the first reflecting mirror 18, the separation optical system 3 and the reduction optical system 6 can be overlapped in the Y-axis direction. In this case, since the second optical axis M of the reduction optical system 6 extends linearly, it is easy to dispose the reduction optical system 6.

[0084] In the fourth embodiment, the same configuration as in the first embodiment can provide the same effects as in the first embodiment.

[0085] [Summary of this disclosure] The following is a summary of this disclosure.

[0086] (Appendix 1) A light source; a separation optical system including a first dichroic mirror that separates a multi-color light including a first color light from among the light emitted from the light source into a first color light in a first wavelength band including blue light and another color light in a wavelength band longer than that of the first color light; a first light modulation element that modulates the first color light separated by the first dichroic mirror; a second light modulation element that modulates the other color light separated by the first dichroic mirror; a reduction optical system in which the first light modulation element is disposed on an enlargement-side image forming surface and which reduces, on a reduction-side image forming surface, a light beam width of the first color light modulated by the first light modulation element; a color synthesis prism that outputs a synthesized light obtained by synthesizing the first color light whose light beam width has been reduced by the reduction optical system and the other color light modulated by the second light modulation element; a projection optical system that projects the combined light emitted from the color combining prism; having an effective area of ​​the first light modulation element is larger than an effective area of ​​the second light modulation element; The separation optical system includes an extension optical system that extends an optical path, a first optical axis of the separation optical system and at least a part of a second optical axis of the reduction optical system are parallel to each other; the portion of the second optical axis is perpendicular to a main surface of a first surface portion of the color synthesis prism onto which the first color light is incident, The projector, when viewed from a direction perpendicular to the first optical axis and the portion of the second optical axis, the extension optical system overlaps with the reduction optical system.

[0087] As a result, the effective area of ​​the first light modulation element is larger than that of the second light modulation element, so that the illuminance irradiated on the first light modulation element can be made smaller than that on the second light modulation element, thereby making it possible to prevent the liquid crystal of the first light modulation element from being deteriorated by light.

[0088] In addition, since the reduction optical system can reduce the beam width of the first color light modulated by the first light modulation element at the reduction side imaging surface, the beam width of each color light incident on the color synthesis prism can be made the same size even if the effective area of ​​the first light modulation element is larger than the effective area of ​​the second light modulation element.

[0089] In addition, since the separation optical system includes an extension optical system that extends the optical path, when viewed from a direction perpendicular to a portion of the first optical axis and the second optical axis, the extension optical system overlaps with the reduction optical system, so that the width of the projector can be made compact in the perpendicular direction.

[0090] (Appendix 2) the first dichroic mirror transmits the first color light in a first direction of the first optical axis; the first light modulation element is located in the first direction of the first dichroic mirror, the reduction optical system includes a first reflecting mirror that reflects the first color light modulated by the first light modulation element in a third direction perpendicular to the first optical axis, and a second reflecting mirror that reflects the first color light reflected by the first reflecting mirror in a second direction opposite to the first direction of the first optical axis, The projector described in Supplementary Note 1, wherein the extension optical system is disposed between the first dichroic mirror and the first light modulation element.

[0091] In this way, the reduction optical system can bend the first color light emitted from the first light modulation element in the first direction in the second direction. As a result, the separation optical system and the reduction optical system can be overlapped in the orthogonal direction.

[0092] (Appendix 3) the first dichroic mirror reflects the first color light in a third direction perpendicular to the first optical axis; the first light modulation element is located in the third direction of the first dichroic mirror, the reduction optical system includes a first reflecting mirror that reflects the first color light modulated by the first light modulation element in a first direction of the first optical axis perpendicular to the third direction, The projector described in Supplementary Note 1, wherein the extension optical system is arranged in the first direction of the first dichroic mirror.

[0093] This allows the separation optical system and the reduction optical system to overlap in the orthogonal direction.

[0094] (Appendix 4) the first dichroic mirror transmits the first color light in a first direction of the first optical axis; a first reflecting mirror that reflects the first color light transmitted by the first dichroic mirror in a third direction perpendicular to the first optical axis, and a second reflecting mirror that reflects the first color light reflected by the first reflecting mirror in a second direction opposite to the first direction of the first optical axis, the first light modulation element is located in the second direction of the second reflection mirror, the extension optical system is disposed between the first dichroic mirror and the first reflecting mirror, The projector described in Supplementary Note 1, wherein the second optical axis extends in a straight line.

[0095] This allows the separation optical system and the reduction optical system to overlap in the perpendicular direction. In addition, since the second optical axis of the reduction optical system extends linearly, it is easy to arrange the reduction optical system.

[0096] (Appendix 5) the first dichroic mirror reflects the first color light in a third direction perpendicular to the first optical axis; a first reflecting mirror that reflects the first color light reflected by the first dichroic mirror in a first direction of the first optical axis perpendicular to the third direction; the extension optical system is disposed in the first direction of the first dichroic mirror, The projector described in Supplementary Note 1, wherein the second optical axis extends in a straight line.

[0097] This allows the separation optical system and the reduction optical system to overlap in the perpendicular direction. In addition, since the second optical axis of the reduction optical system extends linearly, it is easy to arrange the reduction optical system.

[0098] (Appendix 6) 6. The projector according to claim 1, further comprising a polarizing plate disposed between the reduction-side image forming surface and the first screen.

[0099] This makes it possible to suppress a decrease in the contrast of the first color light incident on the color synthesis prism.

[0100] (Appendix 7) the separation optical system includes a second dichroic mirror that separates the emitted light into a third color light in a third wavelength band including red and the multi-color light, the first dichroic mirror separates the multi-color light separated by the second dichroic mirror into the first color light and a second color light in a second wavelength band including green, which is the other color light; the second light modulation element includes a third light modulation element that modulates the second color light separated by the first dichroic mirror, and a fourth light modulation element that modulates the third color light separated by the second dichroic mirror, The projector described in any one of Appendix 1 to 5, characterized in that the color combining prism emits a combined light obtained by combining the first color light whose light beam width has been reduced by the reduction optical system, the second color light whose modulated by the third light modulation element, and the third color light whose modulated by the fourth light modulation element.

[0101] This allows the projector to project full-color composite light.

[0102] (Appendix 8) the separation optical system includes a second dichroic mirror that separates the other color light separated by the first dichroic mirror into a second color light in a second wavelength band including green and a third color light in a third wavelength band including red, the second light modulation element includes a third light modulation element that modulates the second color light separated by the second dichroic mirror, and a fourth light modulation element that modulates the third color light separated by the second dichroic mirror, The projector described in any one of Appendix 1 to 5, characterized in that the color combining prism emits a combined light obtained by combining the first color light whose light beam width has been reduced by the reduction optical system, the second color light whose modulated by the third light modulation element, and the third color light whose modulated by the fourth light modulation element.

[0103] This allows the projector to project full-color composite light.

[0104] (Appendix 9) The projector described in Appendix 7 or 8, characterized in that the luminous flux width of the first color light incident on the first surface of the color synthesis prism is the same as the luminous flux width of the second color light incident on the second surface of the color synthesis prism and the luminous flux width of the third color light incident on the third surface of the color synthesis prism.

[0105] This makes it easy for the color combining prism to combine the various color lights into one combined light.

[0106] (Appendix 10) the first surface portion and the third surface portion face each other in a direction along the portion of the second optical axis, The projector described in Appendix 9, characterized in that in the perpendicular direction, the distance between the first optical axis and the portion of the second optical axis is the same as the distance between the first optical axis and the optical axis of the third color light incident on the third surface portion.

[0107] This makes it possible to prevent the projector from becoming large in the orthogonal direction.

[0108] (Appendix 11) the reduction optical system comprises, in order from the enlargement side to the reduction side, a first lens group consisting of a plurality of lenses and having positive power, a second lens group having one or two lenses, at least one of which is a negative lens and having negative power, and a third lens group consisting of a plurality of lenses and having positive power, the number of lenses in the first lens group is the same as the number of lenses in the third lens group, The projector according to any one of claims 1 to 10, wherein both sides of the reduction optical system are telecentric.

[0109] As a result, the number of lenses in the first lens group and the third lens group on either side of the second lens group are the same, so the various aberrations that occur in the first lens group can be cancelled out by the third lens group. Also, compared to reduction optical systems that are not telecentric on both sides, the installation accuracy of the first light modulation element is not as strict when incorporating the reduction optical system into a projector. Also, the first color light traveling from the reduction-side image plane toward the color synthesis prism becomes parallel light, making it easier to suppress the occurrence of various aberrations that occur in the reduction optical system. [Explanation of symbols]

[0110] 1...light source, 2...illumination optical system, 3...separation optical system, 5...polarizing plate, 6...reduction optical system, 7...light modulation element, 8...color synthesis prism, 9...projection optical system, 10...control unit, 11...lens, 12...lens, 13...reflection mirror, 16...reflection mirror, 17...reflection mirror, 18...first reflection mirror, 19...second reflection mirror, 21...multi-lens, 22...polarizing beam splitter, 23...multi-lens, 24...relay lens, 30...extension optical system, 31...first dichroic mirror, 32...second dichroic mirror, 36...lens, 60A...magnification side image forming surface, 60B...reduction side image forming surface, 61...first reflection mirror, 62...second reflection mirror a first light modulation element, a second light modulation element, a third light modulation element, a fourth light modulation element, a first light modulation element, a second light modulation element, a third light modulation element, a fourth light modulation element, a first light modulation element, a second light modulation element, a first light modulation element, a third light modulation element, a second light modulation element, a first light modulation element, a first light modulation element, a second light modulation element, a third light modulation element, a first light modulation element, a second light modulation element, a first light modulation element, a second light modulation element, a third light modulation element, a first light modulation element, a

Claims

1. A light source; a separation optical system including a first dichroic mirror that separates a multi-color light including a first color light from among the light emitted from the light source into a first color light in a first wavelength band including blue light and another color light in a wavelength band longer than that of the first color light; a first light modulation element that modulates the first color light separated by the first dichroic mirror; a second light modulation element that modulates the other color light separated by the first dichroic mirror; a reduction optical system in which the first light modulation element is disposed on an enlargement-side image forming surface and a light beam width of the first color light modulated by the first light modulation element is reduced on a reduction-side image forming surface; a color synthesis prism that outputs a synthesized light obtained by synthesizing the first color light whose luminous flux width has been reduced by the reduction optical system and the other color light modulated by the second light modulation element; a projection optical system that projects the combined light emitted from the color combining prism; having an effective area of ​​the first light modulation element is larger than an effective area of ​​the second light modulation element; The separation optical system includes an extension optical system that extends an optical path, a first optical axis of the separation optical system and at least a portion of a second optical axis of the reduction optical system are parallel to each other; the portion of the second optical axis is perpendicular to a principal surface of a first surface portion of the color synthesis prism onto which the first color light is incident, The projector, when viewed from a direction perpendicular to the first optical axis and the portion of the second optical axis, the extension optical system overlaps with the reduction optical system.

2. the first dichroic mirror transmits the first color light in a first direction of the first optical axis; the first light modulation element is located in the first direction of the first dichroic mirror, the reduction optical system includes a first reflecting mirror that reflects the first color light modulated by the first light modulation element in a third direction perpendicular to the first optical axis, and a second reflecting mirror that reflects the first color light reflected by the first reflecting mirror in a second direction opposite to the first direction of the first optical axis, The projector according to claim 1 , wherein the extension optical system is disposed between the first dichroic mirror and the first light modulation element.

3. the first dichroic mirror reflects the first color light in a third direction perpendicular to the first optical axis; the first light modulation element is located in the third direction of the first dichroic mirror, the reduction optical system includes a first reflecting mirror that reflects the first color light modulated by the first light modulation element in a first direction of the first optical axis perpendicular to the third direction, The projector according to claim 1 , wherein the extension optical system is disposed in the first direction of the first dichroic mirror.

4. the first dichroic mirror transmits the first color light in a first direction of the first optical axis; a first reflecting mirror that reflects the first color light transmitted by the first dichroic mirror in a third direction perpendicular to the first optical axis, and a second reflecting mirror that reflects the first color light reflected by the first reflecting mirror in a second direction opposite to the first direction of the first optical axis, the first light modulation element is located in the second direction of the second reflecting mirror, the extension optical system is disposed between the first dichroic mirror and the first reflecting mirror, The projector according to claim 1 , wherein the second optical axis extends linearly.

5. the first dichroic mirror reflects the first color light in a third direction perpendicular to the first optical axis; a first reflecting mirror that reflects the first color light reflected by the first dichroic mirror in a first direction of the first optical axis perpendicular to the third direction; the extension optical system is disposed in the first direction of the first dichroic mirror, The projector according to claim 1 , wherein the second optical axis extends linearly.

6. The projector according to claim 1 , further comprising a polarizing plate disposed between the reduction-side image forming surface and the first screen.

7. the separation optical system includes a second dichroic mirror that separates the emitted light into a third color light in a third wavelength band including red and the multi-color light, the first dichroic mirror separates the multi-color light separated by the second dichroic mirror into the first color light and a second color light of a second wavelength band including green, which is the other color light; the second light modulation element includes a third light modulation element that modulates the second color light separated by the first dichroic mirror, and a fourth light modulation element that modulates the third color light separated by the second dichroic mirror, The projector according to claim 1, characterized in that the color combining prism emits a combined light obtained by combining the first color light whose light beam width has been reduced by the reduction optical system, the second color light whose light beam width has been reduced by the third light modulation element, and the third color light whose light beam width has been reduced by the fourth light modulation element.

8. the separation optical system includes a second dichroic mirror that separates the other color light separated by the first dichroic mirror into a second color light in a second wavelength band including green and a third color light in a third wavelength band including red, the second light modulation element includes a third light modulation element that modulates the second color light separated by the second dichroic mirror, and a fourth light modulation element that modulates the third color light separated by the second dichroic mirror, The projector according to claim 1, characterized in that the color combining prism emits a combined light obtained by combining the first color light whose light beam width has been reduced by the reduction optical system, the second color light whose light beam width has been reduced by the third light modulation element, and the third color light whose light beam width has been reduced by the fourth light modulation element.

9. A projector as described in claim 7 or 8, characterized in that the luminous flux width of the first color light incident on the first surface of the color synthesis prism is the same as the luminous flux width of the second color light incident on the second surface of the color synthesis prism and the luminous flux width of the third color light incident on the third surface of the color synthesis prism.

10. the first surface portion and the third surface portion face each other in a direction along the portion of the second optical axis, 10. The projector according to claim 9, wherein, in the perpendicular direction, a distance between the first optical axis and the portion of the second optical axis is the same as a distance between the first optical axis and the optical axis of the third color light incident on the third surface portion.

11. the reduction optical system comprises, in order from the enlargement side to the reduction side, a first lens group consisting of a plurality of lenses and having positive power, a second lens group having one or two lenses, at least one of which is a negative lens and having negative power, and a third lens group consisting of a plurality of lenses and having positive power, the number of lenses in the first lens group is the same as the number of lenses in the third lens group, 2. The projector according to claim 1, wherein both sides of the reduction optical system are telecentric.

Images