Image generating unit and projection type image display device

Abstract

An image generation unit comprising: three light modulation elements that are a first light modulation element, a second light modulation element, and a third light modulation element and modulate light on the basis of an image signal to generate image light; a color separating and combining prism that comprises a first prism, a second prism, and a third prism arranged in order, starting at a light incidence surface of the image generation unit, from front to back on the optical axis, and guides light to each of the three light modulation elements; a light-shielding plate that, of off-light generated by the third light modulation element, absorbs a portion that passed through the third prism, the second prism, and the first prism; and a reflecting surface that reflects, in the direction of the light-shielding plate, the off-light emitted from the first prism.

Description

[Technical field]

[0001] The present invention relates to an image generating section and a projection-type image display device including the image generating section. [Background technology]

[0002] In recent years, projection-type image display devices (projectors) using digital micromirror devices (DMDs) have been developed and are beginning to become widespread. In addition to ON light that is optically modulated based on a video signal to become image light, this digital micromirror device also generates OFF light that does not appear in the video signal and is not used as image light. For this reason, it is necessary to direct the OFF light in a direction different from that of the image light, and for example, a technique has been disclosed that prevents the OFF light from the DMD from entering a color separation / combining prism (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-81931 A Summary of the Invention

[0004] However, if one attempts to position the DMD and the color separation / synthesis prism so as not to allow the OFF light from the DMD to enter the color separation / synthesis prism as described above, it would be necessary to space the DMD and the color separation / synthesis prism at a certain distance, which would result in restrictions such as the overall configuration of the projection-type image display device becoming larger.

[0005] Furthermore, as will be described later, when the OFF light from the DMD is incident on a color separation / synthesis prism, the height of the color separation / synthesis prism needs to be increased in order to allow the OFF light to escape above the prism, resulting in limitations such as a larger overall configuration of the projection type image display device.

[0006] Therefore, an object of the present disclosure is to provide an image generating section including a DMD and a color separation / combining prism that enables a compact configuration of a projection type image display device.

[0007] The image generating unit of the present disclosure includes three light modulation elements, namely a first light modulation element, a second light modulation element, and a third light modulation element, which modulate light based on an image signal to generate image light, a color separation / combination prism consisting of a first prism, a second prism, and a third prism arranged in order from the front to the rear of the optical axis from the light incident surface to guide light to each of the three light modulation elements, a light shielding plate that absorbs a portion of the off light generated by the third light modulation element that has passed through the third prism, the second prism, and the first prism, and a reflective surface that reflects the off light emitted from the first prism in the direction of the light shielding plate.

[0008] The projection type image display device according to the present disclosure comprises a light source unit that generates light, a light guiding optical system that guides the light from the light source unit, an image generation unit that modulates the light guided from the light guiding optical system based on an image signal to generate image light, and a projection optical system that projects the image light.

[0009] According to the image generating section according to the present disclosure and the projection-type image display device using the image generating section, the projection-type image display device can be configured compactly. [Brief description of the drawings]

[0010] [Figure 1] 1 is a block diagram showing a configuration of a projection-type image display device including an image generating section according to a first embodiment. [Diagram 2] 2 is a schematic diagram showing an optical system of a projection-type image display device including the image generating unit of FIG. 1. [Diagram 3] 2 is a schematic perspective view showing a TIR prism and a color separation / combining prism in the projection type image display device according to the first embodiment. FIG. [Figure 4] 4 is a schematic diagram of the TIR prism and color separation / combining prism of FIG. 3 as viewed from the +Z direction. [Diagram 5]4 is a schematic diagram of the TIR prism and color separation / combining prism of FIG. 3 as viewed from the -Y direction. [Figure 6] 1 is a schematic perspective view showing a TIR prism and a color separation / combining prism in a projection-type image display device according to a reference example. [Figure 7] 7 is a schematic diagram of the TIR prism and color separation / combining prism of FIG. 6 as viewed from the +Z direction. [Figure 8] 7 is a schematic diagram of the TIR prism and color separation / combining prism of FIG. 6 as viewed from the -Y direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <Background to this disclosure> FIG. 6 shows the TIR (Total Internal Reflection) of the projection type image display device according to the reference example. Reflection 6. Fig. 7 is a schematic perspective view showing TIR prisms 128, 129 and color separation / combining prism 61A (first prism 134A, second prism 136A, third prism 137A). Fig. 7 is a schematic view of TIR prisms 128, 129 and color separation / combining prism 61A in Fig. 6, viewed from the +Z direction. Fig. 8 is a schematic view of TIR prisms 128, 129 and color separation / combining prism 61A in Fig. 6, viewed from the -Y direction.

[0012] In this color separation / combining prism 61, for example, OFF light 9a, 9b, 9c (OFF light) emitted from third DMD 51B, which is the third light modulation element, is directed in the -Y direction, that is, in the height direction of triangular prism-shaped first prism 134A, second prism 136A, and third prism 137A, and is absorbed by light shielding plate 15 provided on the optical axis side of first prism 134A, as shown in Fig. 7. For this reason, in order for OFF light 9a, 9b, and 9c to pass through first prism 134A, second prism 136A, and third prism 137A, it is necessary to increase the overall height H2 of color separation / combining prism 61A, which causes a problem that the overall configuration of the projection type image display device becomes large.

[0013] Therefore, after careful consideration, the inventors discovered that the height H1 of the color separation / synthesis prism 61 can be reduced by providing a reflective surface 12 that reflects OFF light to the light shielding plate 14 on at least the upper end surface of the first prism 134, i.e., the end surface on the opposite side to the light guided from the light source to the color separation / synthesis prism 61, as shown in Figure 4, and have thus arrived at the present disclosure.

[0014] The image generating unit of the first aspect includes three light modulation elements, namely a first light modulation element, a second light modulation element, and a third light modulation element, which modulate light based on an image signal to generate image light, a color separation / combination prism consisting of a first prism, a second prism, and a third prism arranged in order from the front to the rear of the optical axis from the light incident surface to guide light to each of the three light modulation elements, a light shielding plate that absorbs a portion of the off light generated by the third light modulation element that has passed through the third prism, the second prism, and the first prism, and a reflecting surface that reflects the off light emitted from the first prism in the direction of the light shielding plate.

[0015] The image generating unit of the second aspect is the same as that of the first aspect, in which the reflective surface is provided on the end face of the first prism facing away from the light guided from the light source to the color separation / synthesis prism, and the light blocking plate may be provided on the forward side of the optical axis of the first prism.

[0016] The image generating section according to a third aspect may be the image generating section according to the second aspect, wherein the light blocking plate has a bent portion at an end portion on the optical axis side that is bent toward the surface of the first prism.

[0017] The image generating section according to a fourth aspect may be any of the second and third aspects, wherein the reflecting surface extends from the end face of the first prism to the end face of the second prism.

[0018] The image generating section according to a fifth aspect is any one of the second to fourth aspects, wherein the reflective surface is configured as an upper surface of a glass plate attached to an end face of the first prism.

[0019] The image generating section according to a sixth aspect is any one of the second to fourth aspects, wherein the reflective surface is configured as a surface of a transparent resin applied to the end face of the first prism.

[0020] A projection type image display device according to a seventh aspect includes a light source unit that generates light, a light guiding optical system that guides the light from the light source unit, an image generation unit according to any one of the first to sixth aspects that modulates the light guided from the light guiding optical system based on an image signal to generate image light, and a projection optical system that projects the image light.

[0021] Hereinafter, an image generating section and a projection-type image display device including the image generating section according to an embodiment will be described with reference to the accompanying drawings. Note that in the drawings, substantially the same components are given the same reference numerals.

[0022] (Embodiment 1) <Projector> Fig. 1 is a block diagram showing a configuration of a projection-type image display device (projector) 100 including an image generating section according to embodiment 1. Fig. 2 is a schematic diagram showing an optical system of the projection-type image display device including the image generating section of Fig. 1.

[0023] The projection type image display device 100 according to the first embodiment includes a light source unit 20, a light guide optical system 50, an image generating unit 60, a projection optical system 70, and a control unit 80. The light guide optical system 50 is an optical system that guides light from the light source unit 20 to the image generating unit 60. The image generating unit 60 separates light into three primary colors, RGB, using a color separation / combination prism 61, and modulates each of the RGB lights with an image signal using a digital micromirror device (DMD) to generate image light. The projection optical system 70 projects the generated image light onto a screen or the like to form an image. The control unit 80 controls the light source unit 20, the light guide optical system 50, the image generating unit 60, and the projection optical system 70.

[0024] Each of the components that make up this projection type image display device 100 will be described below.

[0025] <Light source part> Light source section 20 is mainly composed of first light source unit 101a, second light source unit 101b, separation / combining mirror 102, dichroic mirror 107, and phosphor wheel 118. In addition to these, light source section 20 also includes lens groups 103, 106, 112, 113, 116, and 117, mirror groups 104 and 114, and a diffusion plate 105.

[0026] The first light source unit 101a and the second light source unit 101b may be configured with a plurality of solid-state light sources such as laser diodes (LD) or light-emitting diodes (LED). In the first embodiment, among laser diodes, a laser diode that emits blue light is used as the solid-state light source. Here, the laser diode is a type of laser light source.

[0027] The light emitted from first light source unit 101a and second light source unit 101b is, for example, blue light having a wavelength of 440 nm or more and 470 nm or less. This blue light is also used as excitation light for exciting phosphor 119 in phosphor wheel 118.

[0028] <Phosphor wheel> The phosphor wheel 118 rotates around a rotation axis 122 extending along the optical axis of the excitation light. The phosphor wheel 118 is a reflective phosphor wheel that emits fluorescence in the opposite direction to the incident direction of the excitation light. That is, the phosphor wheel 118 has a substrate 121, a phosphor 119 that is applied in an annular shape on the substrate 121 along the rotation direction of the substrate 121, and a motor (not shown) for rotating the substrate 121 on which the phosphor 119 is formed. A reflective film for reflecting the fluorescence emitted by the phosphor 119 is formed on the surface of the substrate 121. The phosphor 119 emits fluorescence including yellow light in response to the excitation light emitted from the first light source unit 101a and the second light source unit 101b.

[0029] The excitation light is diffused by a top hat diffusing element 115 and focused by lenses 116 and 117 onto a phosphor 119, which emits fluorescent light.

[0030] The phosphor is an example of a light-emitting body, and is, for example, a phosphor that emits fluorescence in a wavelength range from green to yellow. The phosphor 119 is preferably a phosphor that efficiently absorbs blue excitation light, efficiently emits fluorescence, and has high resistance to temperature quenching. The phosphor 119 is, for example, Y3A 119, a phosphor having a garnet structure activated by cerium. l5 O 12 :Ce 3+ It is.

[0031] The light source unit 20 guides light (illumination light 1 ) containing blue excitation light and yellow fluorescent light to the light guide optical system 50 .

[0032] <Light guide optical system> The light-guiding optical system 50 is an optical system that guides light (illumination light 1) from the light source unit 20 to the image generating unit 60. The light-guiding optical system 50 mainly includes a rod integrator 111, lens groups 108, 110, 123, 124, and 126, and mirror groups 109 and 125.

[0033] Rod integrator 111 is, for example, a solid rod made of a transparent material such as glass. Rod integrator 111 can homogenize the spatial intensity distribution of the excitation light emitted from first light source unit 101a and second light source unit 101b and the fluorescence from phosphor wheel 118. Rod integrator 111 may be a hollow rod whose inner wall is made of a mirror surface. Rod integrator 111 is a type of light homogenizing element.

[0034] <Image Generation Section> Fig. 3 is a schematic perspective view showing TIR prisms 128, 129 and color separation / combining prism 61 (first prism 134, second prism 136, third prism 137) in projection display device 100 according to embodiment 1. Fig. 4 is a schematic view of TIR prisms 128, 129 and color separation / combining prism 61 in Fig. 3 as viewed from the +Z direction. Fig. 5 is a schematic view of TIR prisms 128, 129 and color separation / combining prism 61 in Fig. 3 as viewed from the -Y direction.

[0035] For convenience, the direction of the optical axis 8 of the image light generated by each light modulation element (DMD) is shown as the +X direction in Fig. 3. Also, in each figure, the height direction of each triangular prism of the color separation / combining prism 61 is shown as the -Y direction. Furthermore, the Z direction perpendicular to the X and Y directions is also shown.

[0036] The image generating unit 60 includes TIR prisms 128, 129 that guide the illumination light 1 from the light-guiding optical system 50 to a color separation / synthesis prism 61, a color separation / synthesis prism 61 consisting of three prisms, a first prism 134, a second prism 136, and a third prism 137, that separate the illumination light 1 into the three primary colors of RGB and combine them, and three digital micromirror devices (DMDs), a first DMD 51G, a second DMD 51R, and a third DMD 51B, that generate image light by modulating the image signals for each of the separated three primary colors of RGB.

[0037] 4, the image generating unit 60 is provided with a reflecting surface 12 on the end face of the first prism 134 in the -Y direction, which reflects the OFF light 9a, 9b, and 9c emitted from the first prism 134 in the direction of the light shielding plate 14. The image generating unit 60 is also provided with a light shielding plate 14 that is provided on the forward side of the optical axis 8 of the first prism 134 and absorbs a portion of the OFF light generated by the third modulation element (third DMD 51B) that has transmitted through the third prism 137, the second prism 136, and the first prism 134.

[0038] <TIRプリズム> The TIR prisms 128 and 129 guide the illumination light 1 from the light-guiding optical system 50 to the color separation / combining prism 61. The TIR prism 128 is made of a light-transmitting member, and has a surface 130 facing the TIR prism 129, and a surface 131 facing a first prism 134 of the color separation / combining prism 61. An air gap is provided between the TIR prism 128 (FIG. 2: surface 130) and the TIR prism 129, and the angle of incidence of the light incident on the TIR prism 128 on surface 130 is greater than the critical angle, so that the light incident on the TIR prism 128 is reflected by surface 130. On the other hand, although an air gap is provided between the TIR prism 128 (FIG. 2: surface 131) and the first prism 134 (FIG. 2: surface 144), the angle at which the light reflected by surface 130 is incident on surface 131 (incident angle) is smaller than the critical angle, so the light reflected by surface 130 is transmitted through surface 131.

[0039] <Light modulation element: Digital micromirror device (DMD)> The first to third light modulation elements (first DMD 51G, second DMD 51R, third DMD 51B) are, for example, digital micromirror devices (DMDs). The first DMD 51G, second DMD 51R, and third DMD 51B, which are digital micromirror devices, are composed of a plurality of movable micromirrors, and each micromirror corresponds to one pixel. The first DMD 51G, second DMD 51R, and third DMD 51B change the angle of each micromirror based on an image signal to switch whether or not to reflect light toward the projection optical system 70, thereby generating image light. The first DMD 51G, second DMD 51R, and third DMD 51B are a type of light modulation element.

[0040] Strictly speaking, the light guided to the first DMD 51G is the first component light (green component light) separated from the illumination light 1 guided from the light guide optical system 50, and the light modulated by the first DMD 51G is the first modulated light (green image light 2a, 2b, 2c). Similarly, the light guided to the second DMD 51R is the second component light (red component light), and the light modulated by the second DMD 51R is the second modulated light (red image light 4a, 4b, 4c). Moreover, the light guided to the third DMD 51B is the third component light (blue component light), and the light modulated by the third DMD 51B is the third modulated light (blue image light 6a, 6b, 6c).

[0041] 4, the first DMD 51G, the second DMD 51R, and the third DMD 51B emit first modulated light (green image light 2a, 2b, 2c), second modulated light (red image light 4a, 4b, 4c), and third modulated light (blue image light 6a, 6b, 6c), which are ON light as image light, and emit OFF light that does not become image light away from the optical axis (X direction). Note that the green image light 2a, 2b, 2c, the red image light 4a, 4b, 4c, and the blue image light 6a, 6b, 6c indicate image light emitted along the width of the first DMD 51G, the second DMD 51R, and the third DMD 51B, respectively.

[0042] Fig. 4 shows only the OFF light 9a, 9b, and 9c emitted from the third DMD 51B, which is the third modulation element. The OFF light emitted from the other first DMD 51G and second DMD 51R is omitted in Fig. 4. The OFF light 9a, 9b, and 9c indicate the OFF light emitted along the width of the third DMD 51B.

[0043] 4, the OFF light 9a, 9b, 9c passes through the third prism 137, the second prism 136, and the first prism 134, and is partially reflected by the reflecting surface 12 and absorbed by the light shielding plate 14. For example, the OFF light 9a, 9b passes through the third prism 137, the second prism 136, and the first prism 134 and is absorbed by the light shielding plate 14, and the OFF light 9c is reflected by the reflecting surface 12 and absorbed by the bent portion 14a of the light shielding plate 14. In this way, the OFF light reflected by the reflecting surface 12 is the portion on the OFF light 9c side, but the range of the OFF light reflected by the reflecting surface 12 changes depending on the height H1 of the color separation / combination prism 61.

[0044] <Color separation / combination prism> The color separation / combination prism 61 is made of a light-transmitting member and includes a first prism 134, a second prism 136, and a third prism 137 arranged in order along the direction of the optical axis 8. The color separation / combination prism 61 may be, for example, a dichroic prism-Philips type. The surface 133 of the first prism 134 is, for example, a dichroic mirror surface that transmits red component light and blue component light and reflects green component light. Therefore, of the illumination light 1 reflected by the surface 130 of the TIR prism 128, the red component light and blue component light transmit through the surface 133, and the green component light is reflected by the surface 133. The green component light reflected by the surface 133 is reflected by the surface 144 and is guided to the first DMD 51G. The surface 135 of the second prism 136 is a dichroic mirror surface that transmits blue component light and reflects red component light. Therefore, of the light incident on the second prism 136, the blue component light is transmitted through surface 135, and the red component light is reflected by surface 135. The red component light reflected by surface 135 is reflected by surface 139 of the second prism 136 and guided to the second DMD 51R. The blue component light that is transmitted through surface 135 of the second prism 136 and incident on the third prism 137 is guided to the third DMD 51B.

[0045] It is also possible to switch the component light guided by the first prism and the third prism, so that the blue component light is guided to the first DMD by the first prism and the green component light is guided to the third DMD by the third prism.

[0046] That is, the green component light, the red component light, and the blue component light are light separated by the color separating / combining prism 61 .

[0047] 5, the first prism 134 receives the green image light 2a, 2b, 2c which is the first modulated light modulated by the first DMD 51G, and guides it to an optical path along the optical axis 8. The second prism 136 receives the red image light 4a, 4b, 4c which is the second modulated light modulated by the second DMD 51R, and guides it to an optical path along the optical axis 8. The third prism 137 receives the blue image light 6a, 6b, 6c which is the third modulated light modulated by the third DMD 51B, and guides it to an optical path along the optical axis 8.

[0048] That is, the green image light 2a, 2b, 2c, the red image light 4a, 4b, 4c, and the blue image light 6a, 6b, 6c are combined by the color separation / combination prism 61 onto the same optical path along the optical axis 8 to become the image light 11 (11a, 11b, 11c).

[0049] <Reflective surface> As shown in the schematic diagram viewed from the +Z direction in FIG. 4, the reflecting surface 12 is provided on the upper end surface of at least the first prism 134, that is, on the end surface in the direction opposite to the illumination light 1 (1a, 1b, 1c) guided from the light source to the color separation / combining prism (-Y direction). The reflecting surface 12 reflects the OFF light (particularly the portion on the OFF light 9c side) emitted from the first prism 134 toward the light blocking plate 14. The reflecting surface 12 may extend from the end surface of the first prism 134 to the end surface of the second prism 136. Furthermore, the reflecting surface 12 may be provided over the ends of the first prism 134, the second prism 136, and the third prism 137.

[0050] By providing a reflecting surface 12 on the upper end surface of the first prism 134, the height H1 of the color separating / combining prism 61 can be reduced.

[0051] The reflecting surface 12 may be, for example, a polished surface formed by polishing the end face in the -Y direction of the first prism 134. The reflecting surface may also be configured as the upper surface of a glass plate bonded to the end face in the -Y direction of the first prism 134. Alternatively, the reflecting surface may be configured as a surface of a transparent resin applied to the end face in the -Y direction of the first prism 134. Note that the present invention is not limited to the above, and it is sufficient that the end face in the -Y direction of the first prism 134 is a smooth surface that functions as a reflecting surface with a sand-rubbed surface as a diffusing surface, and that the reflecting surface 12 is capable of reflecting the OFF light toward the light shielding plate 14.

[0052] The height H1 of the color separation / combination prism 61 may be a height that allows the OFF light 9a emitted from the end of the third DMD 51B in the Y direction to pass through the first prism 134 without entering the TIR prism 129.

[0053] <Light shielding plate> 4, the light shielding plate 14 is provided on the front side of the optical axis 8 of the first prism 134. The light shielding plate 14 may have a bent portion 14a bent toward the surface 144 of the first prism 134 at the end on the optical axis 8 side. This light shielding plate 14 absorbs a part of the OFF light generated by the third modulation element (third DMD 51B) that has passed through the third prism 137, the second prism 136, and the first prism 134. In addition, the bent portion 14a can receive the OFF light reflected by the reflecting surface 12.

[0054] In addition, when the light shielding plate 14 is provided close to the surface on the forward side (X direction) of the optical axis of the first prism 134, the light shielding plate 14 can sufficiently receive the OFF light reflected by the reflecting surface 12, so there is no need to provide the bending portion 14a.

[0055] The light shielding plate 14 may be made of a metal such as aluminum with a black painted surface to reduce reflection of the OFF light. Furthermore, the light shielding plate 14 may have excellent heat dissipation properties.

[0056] <Projection optical system> The projection optical system 70 projects the generated image light 11 onto a screen or the like to form an image.

[0057] <Control Unit> The control unit 80 controls the light source unit 20, the light guiding optical system 50, the image generating unit 60, and the projection optical system 70.

[0058] In addition, the present disclosure includes appropriate combinations of any of the various embodiments and / or examples described above, and can achieve the effects of each embodiment and / or example. [Industrial Applicability]

[0059] According to the image generating section and projection-type image display device of the present invention, the height of the color separating / combining prism can be reduced, and the projection-type image display device can be configured to be compact. [Explanation of symbols]

[0060] 1, 1a, 1b, 1c illumination light 2a, 2b, 2c Green image light 4a, 4b, 4c Red image light 6a, 6b, 6c blue video light 8 Optical axis 9a, 9b, 9c OFF light 11, 11a, 11b, 11c Image light 12 Reflective surface 14, 15 Shading plate 14a Bending part 20 Light source section 50 Light guiding optical system 51G 1st DMD 51R 2nd DMD 51B 3rd DMD 60 Image Generation Unit 61, 61A Color Separation and Combination Prism 70 Projection optics 100 Projection type image display device 101a First light source unit 101b Second light source unit 102 Separate synthetic mirror 103, 106, 108, 110, 112, 113, 116, 117, 123, 124, 126 Lenses 104, 109, 114, 125 Mirror 105 Diffuser 107 Dichroic Mirror 111 Rod Integrator 115 Top Hat Diffusion Element 118 Phosphor Wheel 119 Phosphor 122 Rotational Axis 128, 129, 134, 134A, 136, 136A, 137, 137A Prisms 130, 131, 133, 135, 139, 144 sides

Claims

1. three light modulation elements, a first light modulation element, a second light modulation element, and a third light modulation element, which modulate light based on a video signal to generate video light; a color separation / combination prism including a first prism, a second prism, and a third prism arranged in this order from the light incident surface along an optical axis from the front to the rear, the first prism, and the third prism, which guides light to the three light modulation elements, respectively; a light shielding plate that absorbs a portion of the off-light generated by the third light modulation element and transmitted through the third prism, the second prism, and the first prism; a reflecting surface that reflects the OFF light emitted from the first prism toward the light blocking plate.

2. the reflecting surface is provided on an end surface of the first prism on a side opposite to a side of the light guided from a light source to the color separation / combining prism, The image generating section according to claim 1 , wherein the light blocking plate is provided on a front side of the optical axis of the first prism.

3. The image generating section according to claim 2 , wherein the light blocking plate has a bent portion at an end portion on the optical axis side that is bent toward a surface of the first prism.

4. The image generating section according to claim 2 , wherein the reflective surface extends from an end face of the first prism to an end face of the second prism.

5. The image generating section according to claim 2 , wherein the reflecting surface is configured as an upper surface of a glass plate attached to an end surface of the first prism.

6. The image generating section according to claim 2 , wherein the reflecting surface is configured as a surface of a transparent resin applied to an end face of the first prism.

7. A light source unit that generates light; a light guide optical system that guides light from the light source unit; The image generating unit according to claim 1 , which generates image light by modulating the light guided from the light guide optical system based on an image signal; a projection optical system that projects the image light; A projection type image display device comprising:

Images