Light composition element, optical unit, and projection-type display device

Abstract

To provide a light composition element, an optical unit, and a projection-type display device that can compose four rays of light with a small-sized configuration.SOLUTION: The present invention comprises a prism body having a first surface on which first light is incident, a second surface on which second light is incident, a third surface on which third light and fourth light are incident, an emission surface that composes and emits the rays of light, a first reflecting surface that transmits the second light and the third light and reflects the first light, a second reflecting surface that transmits the first light and the second light and reflects the third light, and a third reflecting surface that transmits the first light, the second light, and the third light, and reflects the fourth light. The first surface is orthogonal to the emission surface. The second surface is directed opposite to the emission surface and orthogonal to the first surface. The third surface intersects the first surface at one end and intersects the emission surface at the other end. The first reflecting surface intersects the first and second surfaces at one end and intersects the third reflecting surface at the other end. The second reflecting surface intersects the second and third surfaces at one end and intersects the first surface and the emission surface at the other end. The third reflecting surface intersects the third surface at one end and intersects the first surface and the emission surface at the other end.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a photosynthetic element, an optical unit, and a projection display device.

Background Art

[0002] Patent Document 1 below discloses a projector that separates blue light into S-polarized light and P-polarized light, modulates the separated blue light with two liquid crystal panels, and then synthesizes the modulated blue image light with green image light modulated by a green liquid crystal panel and red image light modulated by a red liquid crystal panel.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the projector disclosed in Patent Document 1 above, when synthesizing four lights, a first dichroic prism that synthesizes two blue image lights and a second dichroic prism that synthesizes the blue image light synthesized by the first dichroic prism with the remaining two red image lights and green image lights are required. However, using the first dichroic prism requires an optical member for adjusting the focus and the like in the optical paths of the red image light and the green image light, resulting in a problem that the optical system becomes large. Therefore, it is desired to provide a new photosynthetic element that can synthesize four lights with a small configuration.

Means for Solving the Problems

[0005] In order to solve the above problems, according to a first aspect of the present invention, a first surface on which a first light is incident, A second surface on which a second light different from the first light is incident, a third surface on which a third light different from the first light and the second light is incident, a fourth light different from the third light, an emission surface that emits the first light, the second light, the third light, and the fourth light, a first optical layer that transmits the second light and the third light and reflects the first light, a second optical layer that transmits the first light and the second light and reflects the third light, and a third optical layer that transmits the first light, the second light, and the third light and reflects the fourth light, and a prism body having the third optical layer, wherein the first surface of the prism body is orthogonal to the emission surface, the second surface of the prism body faces away from the emission surface and is orthogonal to the first surface, one end of the third surface of the prism body intersects the second surface, the other end intersects the emission surface, one end of the surface forming the first optical layer intersects the first surface and the second surface, and the other end intersects the surface forming the third optical layer, one end of the surface forming the second optical layer intersects the second surface and the third surface, and the other end intersects the first surface and the emission surface, one end of the surface forming the third optical layer intersects the third surface, and the other end intersects the first surface and the emission surface, and a photosynthetic element is provided.

[0006] According to a second aspect of the present invention, there is provided an optical unit including the photosynthetic element according to the first aspect, a first electro-optical device disposed to face the first surface and emitting the first light, a second electro-optical device disposed to face the second surface and emitting the second light, a third electro-optical device disposed to face the third surface and emitting the third light, and a fourth electro-optical device disposed to face the third surface and arranged side by side with the third electro-optical device and emitting the fourth light.

[0007] According to a third aspect of the present invention, there is provided a projection display device including the optical unit according to the second aspect and a projection optical system that projects the light emitted from the optical unit.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that the drawings used in the following description may show the characteristic parts enlarged for convenience of understanding the characteristics, and the dimensional ratios of the respective components are not necessarily the same as the actual ones.

[0010] (First Embodiment) FIG. 1 is a plan view showing a projection display device of the first embodiment. As shown in FIG. 1, the projection display device 100 of the present embodiment includes an image light generation unit (optical unit) 10 and a projection optical system 110 that projects the light emitted from the image light generation unit 10.

[0011] The image light generation unit 10 includes a first display device (first electro-optical device) 11, a second display device (second electro-optical device) 12, a third display device (third electro-optical device) 13, a fourth display device (fourth electro-optical device) 14, and a light combining element 15.

[0012] The first display device 11 emits red image light LR (first light). The second display device 12 emits green image light LG (second light) having a color different from that of the red image light LR. The third display device 13 emits blue image light LBp (third light) having a color different from that of the red image light LR and the green image light LG. The fourth display device 14 emits blue image light LBs (fourth light) having a color different from that of the red image light LR and the green image light LG.

[0013] The first display device 11 includes a backlight (light source) 110, a liquid crystal panel 111, an incident polarizing plate 112, and an exit polarizing plate (polarizing element) 113. The incident polarizing plate 112 and the exit polarizing plate 113 are configured such that their transmission axes are orthogonal to each other (crossed Nicol arrangement), for example. Based on such a configuration, the first display device 11 can emit P-polarized light with respect to the photosynthetic element 15 as red image light LR. That is, the first display device 11 can generate light having a predetermined color light and a predetermined polarization direction as the red image light LR.

[0014] The second display device 12 and the third display device 13 have substantially the same configuration as the first display device 11, except that the color of the image light they emit is different. The second display device 12 includes a backlight (light source) 120, a liquid crystal panel 121, an incident polarizing plate 122, and an exit polarizing plate (polarizing element) 123, and can emit P-polarized light with respect to the photosynthetic element 15 as green image light LG. That is, the second display device 12 can generate light having a predetermined color light and a predetermined polarization direction as the green image light LG.

[0015] The third display device 13 includes a backlight (light source) 130, a liquid crystal panel 131, an incident polarizing plate 132, and an exit polarizing plate (polarizing element) 133, and can emit P-polarized light with respect to the photosynthetic element 15 as blue image light LBp. That is, the third display device 13 can generate light having a predetermined color light and a predetermined polarization direction as the blue image light LBp.

[0016] In the case of this embodiment, the blue image light LBp emitted by the third display device 13 and the blue image light LBs emitted by the fourth display device 14 are the same blue light, but their polarization directions are different. The blue image light LBp is polarized light incident on the photosynthetic element 15 as P-polarized light, and the blue image light LBs is polarized light incident on the photosynthetic element 15 as S-polarized light. That is, the blue image light LBp and the blue image light LBs are orthogonal to each other in terms of their polarization directions.

[0017] The fourth display device 14 has the same configuration as the third display device 13, except that the polarization direction of the emitted image light is different. The fourth display device 14 includes a backlight (light source) 140, a liquid crystal panel 141, an incident polarizing plate 142, and an emission polarizing plate (polarization element) 143. The fourth display device 14 is configured by changing the directions of the transmission axes of the incident polarizing plate 132 and the emission polarizing plate 133 with respect to the liquid crystal panel 131 in the third display device 13 by 90°. That is, the transmission axes of the incident polarizing plate 142 of the fourth display device 14 and the incident polarizing plate 132 of the third display device 13 are orthogonal to each other, and the transmission axes of the emission polarizing plate 143 of the fourth display device 14 and the emission polarizing plate 133 of the third display device 13 are orthogonal to each other. Based on such a configuration, the fourth display device 14 can emit light polarized in the S direction with respect to the photosynthesis element 15 as blue image light LBs.

[0018] The photosynthesis element 15 generates color image light GG by combining the red image light LR emitted from the first display device 11, the green image light LG emitted from the second display device 12, the blue image light LBp emitted from the third display device 13, and the blue image light LBs emitted from the fourth display device 14. That is, the photosynthesis element 15 of the present embodiment combines the four lights emitted from each of the display devices 11, 12, 13, and 14 into one light.

[0019] In the image light generation unit 10 of the present embodiment, the first display device 11 is disposed to face the first surface 151, the second display device 12 is disposed to face the second surface 152, the third display device 13 is disposed to face the third surface 153, and the fourth display device 14 is disposed to face the third surface 153 and side by side with the third display device 13. That is, the third surface 153 includes a first region 1531 facing the third display device 13 and a second region 1532 facing the fourth display device 14. Each of the display devices 11, 12, 13, and 14 is attached to the photosynthesis element 15 via, for example, a housing member (not shown) such that the horizontal and vertical directions of the respective image lights coincide with each other.

[0020] The photosynthetic element 15 includes a prism main body 150. The prism main body 150 has a first surface 151, a second surface 152, a third surface 153, an emission surface 154, a first optical layer 155, a second optical layer 156, and a third optical layer 157, and has a structure in which a plurality of translucent members are joined and integrated.

[0021] The first surface 151 is the surface on which the red image light LR is incident. The second surface 152 is the surface on which the green image light LG is incident. The third surface 153 is the surface on which the blue image light LBp and the blue image light LBs are incident. The blue image light LBp is incident on a first region 1531 which is a part of the third surface 153, and the blue image light LBs is incident on a second region 1532 which is another part of the third surface 153. The emission surface 154 is the surface that emits the red image light LR, the green image light LG, the blue image light LBp, and the blue image light LBs.

[0022] The first surface 151 is orthogonal to the emission surface 154. The second surface 152 faces away from the emission surface 154 and is orthogonal to the first surface 151. One end of the third surface 153 intersects the second surface 152, and the other end intersects the emission surface 154.

[0023] The first optical layer 155 transmits the green image light LG and the blue image light LBp and reflects the red image light LR. The first optical layer 155 is composed of a dielectric multilayer film. The second optical layer 156 transmits the red image light LR and the green image light LG and reflects the blue image light LBp. The second optical layer 156 is composed of a dielectric multilayer film.

[0024] The third optical layer 157 has a polarization separation function of separating by transmitting P-polarized light and reflecting S-polarized light regardless of the wavelength band of the incident light. For this reason, it transmits the blue image light LBp which is P-polarized light and reflects the blue image light LBs which is S-polarized light. In the case of this embodiment, the red image light LR and the green image light LG are incident as P-polarized light on the photosynthetic element 15 as described above. For this reason, the third optical layer 157 reflects the red image light LR and the green image light LG.

[0025] The prism body 150 is formed by joining the cross prism 16 and the triangular prism 17. The cross prism 16 is formed by joining a first prism 161, a second prism 162, a third prism 163, and a fourth prism 164. The first prism 161, the second prism 162, and the fourth prism 164 are each composed of different triangular prism-shaped translucent members. The third prism 163 is composed of a quadrangular prism-shaped translucent member.

[0026] The cross prism 16 includes a first prism portion 16a formed by joining the first prism 161 and the second prism 162, a second prism portion 16b formed by joining the third prism 163 and the fourth prism 164, a third prism portion 16c formed by joining the second prism 162 and the third prism 163, a fourth prism portion 16d formed by joining the first prism 161 and the fourth prism 164, a first joint portion 16e, and a second joint portion 16f.

[0027] The first joint portion 16e is a site where the first prism portion 16a and the second prism portion 16b are joined. The first joint portion 16e includes a translucent adhesive layer (not shown). The first prism portion 16a and the second prism portion 16b have right triangular prism shapes of equal size. The first prism portion 16a and the second prism portion 16b are joined at the first joint portion 16e with the surfaces forming their hypotenuses facing each other.

[0028] The second joint portion 16f is a site where the third prism portion 16c and the fourth prism portion 16d are joined. The second joint portion 16f includes a translucent adhesive layer (not shown). The second joint portion 16f is provided so as to intersect the first joint portion 16e. The third prism portion 16c and the fourth prism portion 16d are joined at the second joint portion 16f with the surfaces forming one side of each other facing each other.

[0029] In the cross prism 16, the surface forming the long side of the two sides sandwiching the hypotenuse in the first prism part 16a having a right triangle shape corresponds to the first surface 151 of the prism main body 150, the surface forming the short side of the first prism part 16a having a right triangle shape corresponds to the second surface 152 of the prism main body 150, and the surface forming the short side of the two sides sandwiching the hypotenuse in the second prism part 16b having a right triangle shape corresponds to the first region 1531 which is a part of the third surface 153 of the prism main body 150. That is, the cross prism 16 includes the first surface 151, the second surface 152, and a part of the third surface 153.

[0030] The triangular prism 17 is composed of a triangular prism-shaped translucent member and is joined to the cross prism 16. The triangular prism 17 has a right triangular prism shape with the same size as the second prism part 16b. The triangular prism 17 and the second prism part 16b are joined to each other to form a regular triangular prism-shaped Kester prism. Thus, the prism main body 150 of the present embodiment is configured by joining three translucent members each having a right triangular prism shape with the same size as each other.

[0031] In the triangular prism 17, the surface forming the hypotenuse of the right triangle corresponds to the emitting surface 154 of the prism main body 150, and the surface forming the adjacent side adjacent to the hypotenuse of the right triangle corresponds to the second region 1532 which is the other part of the third surface 153 of the prism main body 150. That is, the triangular prism 17 includes the emitting surface 154 and the other part of the third surface 153.

[0032] The first optical layer 155 is provided at the first joint part 16e of the cross prism 16. The first optical layer 155 may be provided on the first prism part 16a side at the first joint part 16e, or may be provided on the second prism part 16b side. By forming the first optical layer 155 at the first joint part 16e in this way, the first optical layer 155 can be formed simply and accurately with respect to the photosynthetic element 15.

[0033] The second optical layer 156 is provided at a second joint portion 16f that intersects with the first joint portion 16e of the cross prism 16. The second optical layer 156 may be provided on the side of the third prism portion 16c at the second joint portion 16f, or may be provided on the side of the fourth prism portion 16d. By forming the second optical layer 156 at the second joint portion 16f in this way, the second optical layer 156 can be formed on the photosynthesis element 15 simply and with high accuracy.

[0034] The third optical layer 157 is provided at a third joint portion 158 that joins the second prism portion 16b of the cross prism 16 and the triangular prism 17. The third joint portion 158 includes an adhesive layer (not shown) having translucency. The third optical layer 157 may be provided on the side of the cross prism 16 (second prism portion 16b) at the third joint portion 158, or may be provided on the side of the triangular prism 17. By forming the third optical layer 157 at the third joint portion 158 in this way, the third optical layer 157 can be formed on the photosynthesis element 15 simply and with high accuracy.

[0035] In the prism body 150, the surface on which the first optical layer 155 is formed has one end intersecting with the first surface 151 and the second surface 152, and the other end intersecting with the surface on which the third optical layer 157 is formed. In this specification, the surface on which the first optical layer 155 is formed means the surface of the first prism portion 16a or the second prism portion 16b at the first joint portion 16e, and the surface on which the third optical layer 157 is formed means the surface of the second prism portion 16b or the surface of the triangular prism 17 at the third joint portion 158. For this reason, the one end of the surface on which the first optical layer 155 is formed intersecting with the first surface 151 and the second surface 152 includes not only the case where the surfaces actually intersect with each other, but also the state where the virtual surfaces along the surfaces intersect with each other.

[0036] In the prism body 150, the surface on which the second optical layer 156 is formed has one end intersecting with the second surface 152 and the third surface 153, and the other end intersecting with the first surface 151 and the emission surface 154. In this specification, the surface on which the second optical layer 156 is formed means the surface of the third prism portion 16c or the surface of the fourth prism portion 16d at the second joint portion 16f. Therefore, the intersection of one end of the surface on which the second optical layer 156 is formed with the second surface 152 and the third surface 153 includes not only the case where the surfaces actually intersect with each other, but also the state where the virtual surfaces along the surfaces intersect with each other.

[0037] Here, the specific surface shape of the prism body 150 of this embodiment will be described. In the prism body 150 of this embodiment, the first surface 151 and the second surface 152 intersect at 90°, the first surface 151 and the emission surface 154 intersect at 90°, the second surface 152 and the third surface 153 intersect at 120°, and the third surface 153 and the emission surface 154 intersect at 60°. Also, the first surface 151 intersects the surface on which the first optical layer 155 is formed at 45°, the first surface 151 intersects the surface on which the second optical layer 156 is formed at 30°, the second surface 152 intersects the surface on which the first optical layer 155 is formed at 45°, the second surface 152 intersects the surface on which the second optical layer 156 is formed at 60°, the surface on which the second optical layer 156 is formed intersects the surface on which the third optical layer 157 is formed at 30°, the third surface 153 intersects the surface on which the third optical layer 157 is formed at 90°, the surface on which the third optical layer 157 is formed intersects the emission surface 154 at 30°, and the surface on which the third optical layer 157 is formed intersects the surface on which the second optical layer 156 is formed at 30°.

[0038] Subsequently, the behavior of light in the image light generation unit 10 of this embodiment will be described. The red image light LR emitted from the first display device 11 is incident on the first surface 151 of the prism body 150. The red image light LR travels through the cross prism 16 and is reflected by the first optical layer 155. In the case of this embodiment, the first optical layer 155 is provided at an angle of 45° with respect to the optical axis of the red image light LR. For this reason, the red image light LR is reflected by the first optical layer 155 and travels along the first surface 151 within the fourth prism portion 16d and is incident on the third optical layer 157. Note that the red image light LR is incident on a part of the second optical layer 156 before and after being incident on the first optical layer 155. However, since the second optical layer 156 has the property of transmitting light in a wavelength band other than blue, the second optical layer 156 does not affect the traveling path of the red image light LR.

[0039] Since the third optical layer 157 has the property of transmitting light other than in the blue wavelength band regardless of the polarization state, the red image light LR passes through the third optical layer 157 and is incident from the normal direction with respect to the emission surface 154 orthogonal to the first surface 151. For this reason, the red image light LR is emitted along the normal direction of the emission surface 154 without being refracted by the emission surface 154.

[0040] In addition, the green image light LG emitted from the second display device 12 is incident on the second surface 152 of the prism body 150. The green image light LG travels through the cross prism 16 and is incident on the first optical layer 155 or the second optical layer 156. Since the first optical layer 155 and the second optical layer 156 have the property of transmitting the green image light LG, the first optical layer 155 and the second optical layer 156 do not affect the traveling path of the green image light LG. The green image light LG travels along the first surface 151 within the cross prism 16 and is incident on the third optical layer 157.

[0041] Since the third optical layer 157 has the property of transmitting light other than in the blue wavelength band regardless of the polarization state, the green image light LG passes through the third optical layer 157 and is incident from the normal direction with respect to the emission surface 154 parallel to the second surface 152. For this reason, the green image light LG is emitted along the normal direction of the emission surface 154 without being refracted by the emission surface 154.

[0042] Also, the blue image light LBp emitted from the third display device 13 enters the first region 1531 of the third surface 153 of the prism body 150. The blue image light LBp travels through the cross prism 16 and is reflected by the second optical layer 156. In the case of this embodiment, the second optical layer 156 is provided at an angle of 30° with respect to the optical axis of the blue image light LBp. Therefore, the blue image light LBp is reflected by the second optical layer 156 and travels in the prism body 150 along the first surface 151, and enters the third optical layer 157. Note that although the blue image light LBp enters a part of the first optical layer 155 before and after entering the second optical layer 156, since the first optical layer 155 has the property of transmitting light in a wavelength band other than red, the first optical layer 155 does not affect the path of the blue image light LBp.

[0043] Since the third optical layer 157 has the property of transmitting P-polarized light and reflecting S-polarized light regardless of the wavelength band of light, the blue image light LBp passes through the third optical layer 157 and enters the emission surface 154 orthogonal to the first surface 151 from the normal direction. Therefore, the blue image light LBp is emitted along the normal direction of the emission surface 154 without being refracted at the emission surface 154.

[0044] Also, the blue image light LBs emitted from the fourth display device 14 enters the second region 1532 of the third surface 153 of the prism body 150. The blue image light LBs travels through the cross prism 16 along the surface on which the third optical layer 157 is formed and enters the emission surface 154 at an incident angle smaller than the critical angle. Therefore, the blue image light LBs is totally reflected at the emission surface 154 and enters the surface on which the third optical layer 157 is formed at an angle of 60°.

[0045] The blue image light LBs, which is S-polarized light, is reflected by the third optical layer 157 and enters the emission surface 154 from the normal direction. Therefore, the blue image light LBs is emitted along the normal direction of the emission surface 154 without being refracted at the emission surface 154.

[0046] In this way, the photosynthetic element 15 of the present embodiment can emit the color image light GG synthesized from the four lights incident from the display devices 11, 12, 13, and 14 from the emission surface 154. In the photosynthetic element 15 of the present embodiment, the optical path lengths of the four image lights when passing through the prism body 150 are equal. Therefore, the photosynthetic element 15 of the present embodiment does not require an optical member for adjusting the optical path lengths of the four lights to be synthesized, so that further miniaturization of the device configuration can be achieved.

[0047] Here, in the photosynthetic element 15 of the present embodiment, the green image light LG emitted from the second display device 12 is emitted from the emission surface 154 without being reflected inside the prism body 150. On the other hand, the red image light LR emitted from the first display device 11 and the blue image light LBp emitted from the third display device 13 are emitted from the emission surface 154 after being reflected once inside the prism body 150. Therefore, the images formed by the red image light LR and the blue image light LBp are, for example, images with the top and bottom inverted with respect to the image formed by the green image light LG. On the other hand, the blue image light LBs emitted from the fourth display device 14 is emitted from the emission surface 154 after being reflected twice inside the prism body 150. Therefore, it is inverted with respect to the image formed by the green image light LG in the first reflection, but is inverted again in the second reflection, so that the images formed by the green image light LG and the blue image light LBs are in the same orientation as each other as a result.

[0048] On the other hand, in the image light generation unit 10 of the present embodiment, the red image light LR emitted from the first display device 11 and the blue image light LBp emitted from the second display device 12 are made to generate image lights that are inverted with respect to the green image light LG emitted from the second display device 12. Therefore, according to the image light generation unit 10 of the present embodiment, it is possible to generate the color image light GG in which the image lights of the display devices 11, 12, 13, and 14 are synthesized in the correct orientation.

[0049] The color image light GG generated by the image light generation unit 10 is incident on the projection optical system 110. The projection optical system 110 is composed of a plurality of lenses. The projection optical system 110 enlarges and projects the color image light GG synthesized by the image light generation unit 10 onto a projection surface such as a screen.

[0050] As described above, the photosynthetic element 15 of the present embodiment includes a prism body 150 having a first surface 151 on which the red image light LR is incident, a second surface 152 on which the green image light LG different from the red image light LR is incident, a third surface 153 on which the blue image light LBp different from the red image light LR and the green image light LG and the blue image light LBs different from the blue image light LBp are incident, an emission surface 154 that emits the red image light LR, the green image light LG, the blue image light LBp, and the blue image light LBs, a first optical layer 155 that transmits the green image light LG and the blue image light LBp and reflects the red image light LR, a second optical layer 156 that transmits the red image light LR and the green image light LG and reflects the blue image light LBp, and a third optical layer 157 that transmits the red image light LR, the green image light LG, and the blue image light LBp and reflects the blue image light LBs. The first surface 151 of the prism body 150 is orthogonal to the emission surface 154. The second surface 152 of the prism body 150 faces the opposite side of the emission surface 154 and is orthogonal to the first surface 151. One end of the third surface 153 of the prism body 150 intersects the second surface 152, and the other end intersects the emission surface 154. The surface forming the first optical layer 155 intersects the first surface and the second surface 152 at one end and intersects the surface forming the third optical layer 157 at the other end. The surface forming the second optical layer 156 intersects the second surface 152 and the third surface 153 at one end and intersects the first surface 151 and the emission surface 154 at the other end. The surface forming the third optical layer 157 intersects the third surface 153 at one end and intersects the first surface 151 and the emission surface 154 at the other end.

[0051] According to the photosynthetic element 15 of the present embodiment, since the optical path lengths of the four image lights transmitted through the prism main body 150 can be made equal, an optical member for adjusting the optical path length by making the optical path lengths of the four lights to be synthesized equal becomes unnecessary. Therefore, according to the photosynthetic element 15 of the present embodiment, a photosynthetic element that synthesizes four different lights with a small configuration can be provided.

[0052] According to the image light generation unit 10 of the present embodiment, since the above photosynthetic element 15 is provided, a small optical unit that generates color image light GG by synthesizing the image lights emitted from the respective display devices 11, 12, 13, 14 can be provided.

[0053] According to the image light generation unit 10 of the present embodiment, since blue image light having relatively high energy compared to other color lights is generated by the two display devices 13, 14, the amount of blue light incident on the liquid crystal panels 131, 141 constituting the respective display devices 13, 14 can be suppressed as compared with the case where blue image light is generated by one display device. Therefore, the lifetimes of the liquid crystal panels 131, 141 that generate blue image light can be extended.

[0054] Further, according to the projection display device 100 of the present embodiment, since the above image light generation unit 10 is provided, a display device that can project color image light GG while miniaturizing the device configuration can be provided.

[0055] (First Modification Example) Subsequently, a first modification example of the projection display device according to the first embodiment will be described. FIG. 2 is a plan view showing the projection display device of this modification example. As shown in FIG. 2, the projection display device 100A of this modification example includes an image light generation unit 20 and a projection optical system 110 that projects the light emitted from the image light generation unit 20. The image light generation unit 20 includes a first display device 21, a second display device 22, a third display device 13, a fourth display device 14, and a photosynthetic element 115. In FIG. 2, the respective display devices 21, 22, 13, 14 are illustrated in a simplified manner.

[0056] In the case of this modified example, the first display device 21 is arranged to face the first surface 151 of the photosynthetic element 115 and emits green image light LG (first light). The second display device 22 is arranged to face the second surface 152 of the photosynthetic element 115 and emits red image light LR (second light). In this modified example, the first surface 151 is the surface on which the green image light LG is incident, and the second surface 152 is the surface on which the red image light LR is incident.

[0057] That is, the configuration of the projection display device 100A of this modified example is different from that of the projection display device 100 of the first embodiment in that the positions where the red image light LR and the green image light LG are incident on the photosynthetic element 15 are interchanged.

[0058] In the photosynthetic element 115 of this modified example, the first optical layer 155 is composed of a dielectric multilayer film that transmits the red image light LR and the blue image light LBp and reflects the green image light LG. Note that the second optical layer 156 and the third optical layer 157 have the same configuration as those of the first embodiment.

[0059] Also in the photosynthetic element 115 of this modified example, four different lights can be synthesized with a small configuration. Also in the image light generation unit 20 of this modified example, a small optical unit that generates color image light GG can be provided. Also in the projection display device 100A of this modified example, since the above-described image light generation unit 20 is provided, a display device that can project the color image light GG while miniaturizing the device configuration can be provided.

[0060] Note that in the projection display device 100 of the first embodiment, the incident positions of the blue image light LBp and the blue image light LBs with respect to the photosynthetic element 15 may be interchanged. In this case, as the third optical layer 157, a polarization separation film that transmits S-polarized light and reflects P-polarized light regardless of the wavelength band of the incident light may be used, and the red image light LR and the green image light LG may be incident on the photosynthetic element 15 as S-polarized light.

[0061] (Second Modified Example) Next, a second modification of the projection display device according to the first embodiment will be described. FIG. 3 is a plan view showing the projection display device of this modification. As shown in FIG. 3, the projection display device 100B of this modification includes an image light generation unit 40 and a projection optical system 110 that projects the light emitted from the image light generation unit 40. The image light generation unit 40 includes a first display device 41, a second display device 42, a third display device 43, a fourth display device 44, and a light synthesizing element 15.

[0062] In the case of this modification, the first display device 41 includes a self-luminous panel 411 and a polarization conversion member 412, the second display device 42 includes a self-luminous panel 421 and a polarization conversion member 422, the third display device 43 includes a self-luminous panel 431 and a polarization conversion member 432, and the fourth display device 44 includes a self-luminous panel 441 and a polarization conversion member 442.

[0063] Each of the self-luminous panels 411, 421, 431, 441 is composed of an organic EL panel having a top emission type organic electroluminescence (EL) element. Therefore, each color light emitted from each of the self-luminous panels 411, 421, 431, 441 is non-polarized light having no polarization characteristics.

[0064] On the other hand, each of the display devices 41, 42, 43, 44 aligns the polarization directions of the light emitted from the self-luminous panels 411, 421, 431, 441 by the respective polarization conversion members 412, 422, 432, 442. According to this configuration, each of the display devices 41, 42, 43, 44 can generate light having a predetermined color light and a predetermined polarization direction as each image light.

[0065] Based on such a configuration, each of the display devices 41, 42, 43, 44 can emit a red image light LR, a green image light LG, a blue image light LBp, and a blue image light LBs having a predetermined polarization direction, similar to the configuration of the first embodiment.

[0066] Also in the photosynthesis element 15 of this modification example, four different lights can be synthesized with a small configuration. Further, also in the image light generation unit 40 of this modification example, a small optical unit that generates color image light GG can be provided. Further, also in the projection display device 100B of this modification example, since the above-described image light generation unit 40 is provided, a display device that can project color image light GG while miniaturizing the device configuration can be provided.

[0067] Note that the self-emitting panels 411, 421, 431, and 441 are not limited to organic EL panels, and self-emitting panels such as inorganic EL panels and micro LED panels may be used.

[0068] (Second Embodiment) Subsequently, the configuration of the projection display device according to the second embodiment of the present invention will be described. The difference between this embodiment and the first embodiment is the structure of the image light generation unit and the wavelength band of the light synthesized by the image light generation unit. Therefore, hereinafter, the same reference numerals are given to the configurations or members common to the first embodiment, and the detailed description thereof is omitted.

[0069] FIG. 4 is a plan view showing the projection display device of this embodiment. As shown in FIG. 4, the projection display device 102 of this embodiment includes an image light generation unit 120 and a projection optical system 110 that projects the light emitted from the image light generation unit 20. The image light generation unit 120 includes a first display device 11, a second display device 12, a third display device 23, a fourth display device 34, and a photosynthesis element 215. In FIG. 4, each display device 11, 12, 23, and 24 is shown in a simplified manner.

[0070] The third display device 23 emits blue image light LB1 (third light), and the fourth display device 34 emits blue image light LB2 (fourth light). In the case of this embodiment, the blue image light LB1 and the blue image light LB2 are the same blue color light, and their wavelength bands are different. Specifically, the blue image light LB1 is light in the long wavelength band having a relatively long wavelength in the blue band, and the blue image light LB2 is light in the short wavelength band having a relatively short wavelength in the blue band.

[0071] That is, the configuration of the projection display device 102 of the present embodiment is different in that the two lights incident on the third surface of the photosynthetic element in the projection display device 100 of the first embodiment are colored lights of the same color and lights having different wavelength bands are used.

[0072] In the photosynthetic element 215 of the present embodiment, the third optical layer 257 is composed of a dielectric multilayer film that reflects light with a short wavelength in the blue band and transmits light with a long wavelength in the blue band, and transmits light in other wavelength bands regardless of the polarization direction. Note that the first optical layer 155 and the second optical layer 156 have the same configuration as those in the first embodiment.

[0073] Also in the photosynthetic element 215 of the present embodiment, four different lights can be synthesized with a small configuration. In the photosynthetic element 215 of the present embodiment, since the blue image lights LB1 and LB2 are synthesized in the third optical layer 257 by utilizing the difference in wavelength bands, it is not necessary to consider the polarization directions of the red image light LR and the green image light LG. That is, since the third optical layer 257 transmits the red image light LR and the green image light LG regardless of the polarization direction, it is not necessary to adjust the polarization directions of the lights emitted from the first display device 11 and the second display device 12. Therefore, the degree of freedom in the design of the first display device 11 and the second display device 12 can be improved.

[0074] Further, also in the image light generation unit 120 of the present embodiment, a small optical unit that generates the color image light GG2 obtained by synthesizing the four image lights LR, LG, LB1, and LB2 can be provided. Also, in the projection display device 102 of the present embodiment, since the above-described image light generation unit 120 is provided, a display device that can project the color image light GG while miniaturizing the device configuration can be provided.

[0075] Note that the technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. In addition, the specific configurations such as the number, arrangement, shape, and material of various components constituting the light source device are not limited to the above embodiments and can be appropriately changed.

[0076] For example, in the above embodiment, an optical unit using the prism of the present invention was taken as an example, but the prism of the present invention may also be applied to an illumination device or a light source device including four light-emitting elements that emit different lights toward the prism.

[0077] Hereinafter, a summary of the present disclosure is appended.

[0078] (Appendix 1) A first surface on which a first light is incident, A second surface on which a second light different from the first light is incident, A third surface on which a third light different from the first light and the second light and a fourth light different from the third light are incident, An emitting surface that emits the first light, the second light, the third light, and the fourth light, A first optical layer that transmits the second light and the third light and reflects the first light, A second optical layer that transmits the first light and the second light and reflects the third light, A prism body having a third optical layer that transmits the third light and reflects the fourth light, The first surface of the prism body is orthogonal to the emitting surface, The second surface of the prism body faces away from the emitting surface and is orthogonal to the first surface, One end of the third surface of the prism body intersects the second surface, and the other end intersects the emitting surface, The surface on which the first optical layer is formed intersects the first surface and the second surface at one end and intersects the surface on which the third optical layer is formed at the other end, The surface on which the second optical layer is formed intersects the second surface and the third surface at one end and intersects the first surface and the emitting surface at the other end, The surface on which the third optical layer is formed intersects the third surface at one end and intersects the first surface and the emitting surface at the other end, Photosynthetic element.

[0079] According to the photosynthetic element with this configuration, since the optical path lengths of the four lights transmitted through the prism body can be made equal, an optical member for adjusting the optical path length by making the optical path lengths of the four lights to be synthesized equal becomes unnecessary. Therefore, a photosynthetic element that synthesizes four different lights with a small configuration can be provided.

[0080] (Appendix 2) The third light and the fourth light are colored lights of the same color, and their polarization directions are different from each other. The photosynthetic element according to Appendix 1.

[0081] According to this configuration, a photosynthetic element that synthesizes the third light and the fourth light of the same color with different polarization directions, the first light, and the second light can be realized.

[0082] (Appendix 3) The third light and the fourth light are colored lights of the same color, and their wavelength bands are different from each other. The photosynthetic element according to Appendix 1 or Appendix 2.

[0083] According to this configuration, a photosynthetic element that synthesizes the third light and the fourth light of the same color with different wavelength bands, the first light, and the second light can be realized.

[0084] (Appendix 4) The prism body is joined by a cross prism including the first surface, the second surface, a part of the third surface, and the fifth surface, and a triangular prism including the emission surface and the other part of the third surface. The photosynthetic element according to any one of Appendices 1 to 3.

[0085] According to this configuration, the prism body can be formed simply and accurately.

[0086] (Appendix 5) The first optical layer is provided at the first joint portion of the cross prism. The second optical layer is provided at a second joint portion that intersects the first joint portion of the cross prism. The third optical layer is provided at a third joint portion where the cross prism and the triangular prism are joined. The photosynthetic element according to Supplementary Note 4.

[0087] According to this configuration, the first optical layer, the second optical layer, and the third optical layer can be formed on the prism body simply and with high accuracy.

[0088] (Supplementary Note 6) The first surface and the second surface intersect at 90°. The first surface and the emission surface intersect at 90°. The second surface and the third surface intersect at 120°. The third surface and the emission surface intersect at 60°. The photosynthetic element according to Supplementary Note 4 or Supplementary Note 5.

[0089] According to this configuration, it is possible to realize a photosynthetic element that aligns the directions of four image lights emitted from each display device at the emission surface.

[0090] (Supplementary Note 7) The photosynthetic element according to any one of Supplementary Notes 1 to 6, A first electro-optical device that is disposed opposite to the first surface and emits the first light, A second electro-optical device that is disposed opposite to the second surface and emits the second light, A third electro-optical device that is disposed opposite to the third surface and emits the third light, A fourth electro-optical device that is disposed opposite to the third surface and arranged side by side with the third electro-optical device and emits the fourth light, An optical unit.

[0091] According to the optical unit of this configuration, since it includes the above photosynthetic element, it is possible to provide a small optical unit that synthesizes the light emitted from each electro-optical device.

[0092] (Supplementary Note 8) The first electro-optical device, the second electro-optical device, and the third electro-optical device include a light source, a liquid crystal panel, and a polarization element onto which the light emitted from the liquid crystal panel is incident. The optical unit according to Supplementary Note 7.

[0093] According to this configuration, as each image light, light having a predetermined color light and a predetermined polarization direction can be generated.

[0094] (Supplementary Note 9) The first electro-optical device, the second electro-optical device, and the third electro-optical device include a self-luminous panel and a polarization conversion member that aligns the polarization directions of the light emitted from the panel. The optical unit according to Supplementary Note 7.

[0095] According to this configuration, as each image light, light having a predetermined color light and a predetermined polarization direction can be generated.

[0096] (Supplementary Note 10) The optical unit according to any one of Supplementary Notes 7 to 9, and a projection optical system that projects the light emitted from the optical unit. A projection display device.

[0097] According to the projection display device having this configuration, since an image light generation unit that synthesizes the four image lights emitted from each display device in the correct direction is provided, a projector capable of projecting the synthesized image light while miniaturizing the device configuration can be provided.

Explanation of Reference Numerals

[0098] 10…Image light generation unit (optical unit), 11…First display device (first electro-optical device), 11, 41…Display device, 12…Second display device (second electro-optical device), 13…Third display device (third electro-optical device), 14…Fourth display device (fourth electro-optical device), 15, 115, 215, 1115…Photosynthetic element, 16…Cross prism, 16e…First joint, 16f…Second joint, 17…Triangular prism, 100, 100A, 100B, 102…Projection display device, 110, 120, 130, 140…Backlight (light source), 110…Projection optical system, 111, 121, 131, 141…Liquid crystal panel, 113, 123, 133, 143…Emission polarizing plate (polarizing element), 150…Prism body, 151…First surface, 152…Second surface, 153…Third surface, 154…Emission surface, 155…First optical layer, 156…Second optical layer, 157, 257…Third optical layer, 158…Third joint, 411, 421, 431, 441…Self-luminous panel, 412, 422, 432, 442…Polarization conversion member.

Claims

1. a first surface on which a first light is incident; a second surface on which a second light different from the first light is incident; a third surface on which a third light different from the first light and the second light, and a fourth light different from the third light are incident; an emission surface that emits the first light, the second light, the third light, and the fourth light; a first optical layer that transmits the second light and the third light and reflects the first light; a second optical layer that transmits the first light and the second light and reflects the third light; a prism body having a third optical layer that transmits the first light, the second light, and the third light and reflects the fourth light; the first surface of the prism body is orthogonal to the emission surface; the second surface of the prism body faces the opposite side of the emission surface and is orthogonal to the first surface; one end of the third surface of the prism body intersects the second surface, and the other end intersects the emission surface; one end of the surface on which the first optical layer is formed intersects the first surface and the second surface, and the other end intersects the surface on which the third optical layer is formed; one end of the surface on which the second optical layer is formed intersects the second surface and the third surface, and the other end intersects the first surface and the emission surface; one end of the surface on which the third optical layer is formed intersects the third surface, and the other end intersects the first surface and the emission surface; a photosynthetic element.

2. the third light and the fourth light are colored lights of the same color and have different polarization directions from each other; the photosynthetic element according to claim 1.

3. the third light and the fourth light are colored lights of the same color and have different wavelength bands from each other; the photosynthetic element according to claim 1.

4. the prism body is joined by a cross prism including the first surface, the second surface, a part of the third surface, and a fifth surface, and a triangular prism including the emission surface and the other part of the third surface; the photosynthetic element according to claim 1.

5. the first optical layer is provided at a first joint portion of the cross prism; the second optical layer is provided at a second joint portion that intersects the first joint portion of the cross prism; the third optical layer is provided at a third joint portion where the cross prism and the triangular prism are joined; the photosynthetic element according to claim 4.

6. the second surface and the third surface intersect at 120°; the third surface and the emission surface intersect at 60°; the photosynthetic element according to claim 4 or claim 5.

7. the photosynthetic element according to claim 1; A first electro-optical device that is disposed to face the first surface and emits the first light; A second electro-optical device that is disposed to face the second surface and emits the second light; A third electro-optical device that is disposed to face the third surface and emits the third light; A fourth electro-optical device that faces the third surface and is disposed side by side with the third electro-optical device and emits the fourth light, and an optical unit comprising the same. Optical unit.

8. The first electro-optical device, the second electro-optical device, and the third electro-optical device include a light source, a liquid crystal panel, and a polarizing element into which the light emitted from the liquid crystal panel is incident. The optical unit according to claim 7.

9. The first electro-optical device, the second electro-optical device, and the third electro-optical device include a self-luminous panel and a polarization conversion member that aligns the polarization directions of the light emitted from the self-luminous panel. The optical unit according to claim 7.

10. An optical unit according to any one of claims 7 to 9; A projection optical system that projects the light emitted from the optical unit, and a projection display device comprising the same. Projection display device.

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