Light source device and projector

Abstract

The invention provides a light source device and a projector, which can restrain the enlargement of the light source device for the projector. This light source device is provided with: a first light source that emits first light of a first wavelength band; a second light source that emits second light of a second wavelength band different from the first wavelength band; a light conversion element that converts the incident first light into third light of a third wavelength band different from the first wavelength band; an optical path changing element that matches an optical path of first light emitted from the first light source and incident from a first direction with an optical path of second light emitted from the second light source and incident from a second direction intersecting the first direction; and a light guide optical system that guides the first light and the second light emitted from the optical path changing element to the light conversion element. The light guide optical system reflects the first light, the second light, and the third light emitted from the light conversion element.

Description

Technical Field

[0001] The invention relates to a light source device and a projector. Background Art

[0002] For example, a projector is used as a display device for magnifying and displaying an image on a display surface such as a screen. The projector includes: a light source device that emits color light; a light modulation device that modulates the color light emitted from the light source device according to image information to generate image light; and a projection optical system that projects the image light emitted from the light modulation device onto the display surface.

[0003] An example of a light source device for a projector is disclosed in Patent Document 1. The light source device disclosed in Patent Document 1 includes: a first blue laser light source that emits blue light as excitation light for a phosphor; a phosphor that is excited by the excitation light and emits yellow light; a red laser light source that emits red light; a first light synthesizing unit that synthesizes the yellow light and the red light to emit the first light; a second blue laser light source that emits blue light as the second light different from the blue light as the excitation light; and a second light synthesizing unit that synthesizes the first light emitted from the first light synthesizing unit and the second light emitted from the blue laser light source to emit white light.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2016-224304

[0005] In the light source device disclosed in Patent Document 1, the optical paths of the blue light emitted from the first blue laser light source until it enters the phosphor and the yellow light emitted from the excited phosphor, and the optical path of the red light emitted from the red laser light source until it is combined with the yellow light, are respectively provided, and do not overlap with each other. Therefore, in the light source device disclosed in Patent Document 1, it is necessary to set the optical path of the blue light as the excitation light and the optical paths of the yellow light and the red light other than the excitation light in different regions, and the light source device may be enlarged. That is, it is desired to take measures to suppress the enlargement of the light source device having the phosphor, the light source emitting the excitation light that excites the phosphor, and the other light sources emitting the color light. Summary of the invention

[0006] A light source device according to one embodiment of the present invention comprises: a first light source that emits a first light of a first wavelength band; a second light source that emits a second light of a second wavelength band different from the first wavelength band; a light conversion element that converts the incident first light into a third light of a third wavelength band different from the first wavelength band; an optical path changing element that makes the optical path of the first light emitted from the first light source and incident from a first direction coincide with the optical path of the second light emitted from the second light source and incident from a second direction intersecting the first direction; and a light guide optical system that guides the first light and the second light emitted from the optical path changing element to the light conversion element. The light guide optical system reflects the first light, the second light, and the third light emitted from the light conversion element. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a schematic diagram showing the structure of the projector according to the first embodiment.

[0008] Figure 2 yes Figure 1 A schematic diagram of a light source device for a projector.

[0009] Figure 3 yes Figure 2 Schematic diagram of a wavelength conversion device of a light source device.

[0010] Figure 4 yes Figure 3 A cross-sectional view of a wavelength conversion device.

[0011] Figure 5 yes Figure 3 A cross-sectional view of a wavelength conversion device.

[0012] Figure 6 It is shown from Figure 2 A graph showing an example of light intensity distribution of colored light emitted by a wavelength conversion device of a light source device.

[0013] Figure 7 It is shown Figure 2 A graph showing an example of reflectance characteristics of a wavelength selective reflection layer of a light source device.

[0014] Figure 8 This is a schematic diagram of an optical device according to a second embodiment.

[0015] Fig. 9 It shows the composition Figure 8 A graph showing an example of the transmittance characteristics of a dichroic mirror of a light guide optical system of a light source device.

[0016] Fig.10 yes Figure 8 Schematic diagram of a wavelength conversion device of a light source device.

[0017] Fig.11 yes Fig.10 A cross-sectional view of a wavelength conversion device.

[0018] Fig.12 yes Figure 8 A schematic diagram of a wavelength conversion device of a modified example of a light source device.

[0019] Fig.13 yes Fig.12 A cross-sectional view of a wavelength conversion device.

[0020] Fig.14 yes Fig.12 Another cross-sectional view of a wavelength conversion device.

[0021] Fig.15 yes Figure 8 A schematic diagram of a portion of a modified example of a light source device.

[0022] Fig.16 yes Figure 2 A schematic diagram of a modified example of a light source device.

[0023] Fig.17 It is composed Fig.16 Schematic diagram of optical elements of a light guide optical system of a light source device.

[0024] Fig.18 It is composed Figure 2 A schematic diagram of optical elements of a light guide optical system of another modified example of a light source device.

[0025] Fig.19 It is shown Fig.18 A graph showing an example of transmittance characteristics of a wavelength selective transmission film of an optical element.

[0026] Fig. 20 yes Figure 2 A schematic diagram of other variations of the light source device.

[0027] Description of symbols

[0028] 10: projector; 11: first light source; 12: second light source; 32: optical path changing element; 45: light guiding optical system; 50: wavelength conversion device (light conversion element); 100, 102, 104: light source device. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each of the drawings, in order to make each component easier to see, the scale of the dimensions may be changed depending on the component.

[0030] First Embodiment

[0031] First, refer to Figures 1 to 7 A first embodiment of the present invention will be described. Figure 1 1 is a schematic diagram showing the structure of a projector 10 according to a first embodiment of the present invention. The projector 10 is a projection type display device that displays images and videos on a screen SCR. The projector 10 includes a light source device 100, a color separation optical system 200, field lenses 300R, 300G, 300B, light modulation devices 400R, 400G, 400B, a color synthesis optical system 500, and a projection optical system 600. The projector 10 is a three-panel projector having three light modulation devices.

[0032] The light source device 100 emits blue light BL, green light GL, and red light RL as white light toward the color separation optical system 200. The red light RL, the green light GL, and the blue light BL are illumination lights in the projector 10. In the following description, the blue light BL and the green light GL, or the red light RL emitted from the light source device 100 are sometimes collectively described as colored light. The structure of the light source device 100 will be described later. The green light GL includes at least one of the green lights GL1, GL2, and GL3 described later.

[0033] The color separation optical system 200 separates the incident red light RL, green light GL, and blue light BL into separate optical paths. The color separation optical system 200 includes, for example, dichroic mirrors 210 and 220 , total reflection mirrors 230 , 240 , and 250 , and relay lenses 260 and 270 .

[0034] The dichroic mirror 210 is arranged on the optical path of the colored light emitted from the light source device 100, and separates the incident colored light into red light RL, green light GL, and blue light BL. For example, the dichroic mirror 210 transmits the red light RL and reflects the green light GL and the blue light BL. The dichroic mirror 220 is arranged on the common optical path of the green light GL and the blue light BL emitted from the dichroic mirror 210, and separates the green light GL and the blue light BL. For example, the dichroic mirror 220 transmits the blue light BL and reflects the green light GL.

[0035] Total reflection mirror 230 reflects red light RL toward light modulator 400R. Total reflection mirrors 240 and 250 guide blue light BL to light modulator 400B. Green light GL is reflected from dichroic mirror 220 toward light modulator 400G. Red light RL, green light GL, and blue light BL correspond to light emitted from light source device 100.

[0036] The relay lens 260 is arranged on the optical path of the blue light BL between the dichroic mirror 220 and the total reflection mirror 240. The relay lens 270 is arranged on the optical path of the blue light BL between the total reflection mirror 240 and the total reflection mirror 250. The optical path length of the blue light BL from the dichroic mirror 210 to the light modulator 400B is longer than the optical path length of the red light RL from the dichroic mirror 210 to the light modulator 400R and the optical path length of the green light GL from the dichroic mirror 210 to the light modulator 400G. Therefore, if the relay lens is not arranged on the optical path of the blue light BL, the optical loss of the blue light BL is greater than the optical loss of the red light RL and the green light GL. By arranging the relay lenses 260 and 270 as described above, the optical loss of the blue light BL is compensated.

[0037] The light modulator 400R is disposed on the optical path of the red light RL reflected by the total reflection mirror 230 and emitted from the total reflection mirror 230. The light modulator 400R modulates the incident red light RL according to image information input from an image input device (not shown) to form red image light, and emits the red image light. The image input device is, for example, a personal computer or a portable terminal device.

[0038] The light modulator 400G is disposed on the optical path of the green light GL reflected by the dichroic mirror 220 and emitted from the dichroic mirror 220. The light modulator 400G modulates the incident green light GL based on the image information input from the image input device, forms green image light, and emits the green image light.

[0039] The light modulator 400B is disposed on the optical path of the blue light BL reflected by the total reflection mirror 250 and emitted from the total reflection mirror 250. The light modulator 400B modulates the incident blue light BL based on the image information input from the image input device, forms blue image light, and emits the blue image light.

[0040] The light modulators 400R, 400G, and 400B use, for example, transmissive liquid crystal panels, respectively. Polarizing plates (not shown) are arranged in the incident side region and the emission side region of the liquid crystal panel. The field lens 300R is arranged on the optical path of the red light RL between the total reflection mirror 230 and the polarizing plate on the incident side of the light modulator 400R. The field lens 300G is arranged on the optical path of the green light GL between the dichroic mirror 220 and the polarizing plate on the incident side of the light modulator 400G. The field lens 300B is arranged on the optical path of the blue light BL between the total reflection mirror 250 and the polarizing plate on the incident side of the light modulator 400B.

[0041] The color synthesis optical system 500 is disposed in a region where the optical paths of the red image light emitted from the light modulator 400R, the green image light emitted from the light modulator 400G, and the blue image light emitted from the light modulator 400B intersect. Figure 1 As shown, when viewed from above or from the side, the position where the colored light in the color synthesis optical system 500 passes overlaps at the position where the optical path of the red image light, the optical path of the green image light, and the optical path of the blue image light intersect each other. The color synthesis optical system 500 emits the incident red image light, green image light, and blue image light in the same direction as each other, guides each image light to the same optical path as each other, and synthesizes them. The image light of each color emitted from the color synthesis optical system 500 is equivalent to the light modulated by the light modulation devices 400R, 400G, and 400B. The color synthesis optical system 500 uses, for example, a cross dichroic prism.

[0042] The projection optical system 600 is arranged on the optical path of the image light of each color emitted from the color synthesis optical system 500. The projection optical system 600 magnifies and projects the image light of each color emitted from the color synthesis optical system 500 and incident toward the screen SCR. The projection optical system 600 is composed of, for example, a plurality of optical lenses, but may also be composed of one optical lens. The optical lens includes, for example, various lenses such as a plano-convex lens, a biconvex lens, a concave-convex lens, an aspherical lens, a rod lens, and a free-form surface lens.

[0043] The image lights of various colors magnified and projected from the projection optical system 600 are displayed on the screen SCR on the emission surface of the projection optical system 600 and the display surface opposite to the emission port of the image light in the projector 10. On the screen SCR, the red image light, the green image light, and the blue image light are displayed at separate emission times according to the prescribed emission times of the red light RL, the green light GL, and the blue light BL emitted from the light source device 100. Since the prescribed emission time is set to be shorter than the time resolution of a person as an observer, the red, green, and blue image lights are synthesized by the afterimage effect, and the observer visually recognizes the image lights of various colors as a full-color image.

[0044] Next, a light source device 100 according to a first embodiment of the present invention will be described. Figure 2 yes Figure 1A schematic diagram of a light source device 100 provided in a projector 10 of FIG. The light source device 100 includes a first light source 11, a second light source 12, a wavelength conversion device 50A, an optical path changing element 32, a light guiding optical system 45, and a total reflection mirror 73, and further includes a reflection element 31, a beam expander 35, a homogenizing element 40, a lens 81, a superimposing lens 82, and a rod lens 85. In the following description, a direction corresponding to a height direction when looking down at the light source device 100 is set as a Z direction. A direction orthogonal to the Z direction is set as an X direction, and a direction orthogonal to the Z direction and the X direction is set as a Y direction. One side of the X direction is set as a -X side, and the other side of the X direction is set as a +X side. One side of the Y direction is set as a -Y side, and the other side of the Y direction is set as a +Y side. One side of the Z direction is set as a -Z side, and the other side of the Z direction is set as a +Z side.

[0045] The first light source 11 emits blue light BL in a blue wavelength band including at least a blue wavelength in the visible wavelength band toward the +Y side along the Y direction. The blue light BL corresponds to the first light. The blue wavelength band corresponds to the first wavelength band, for example, a wavelength band of 420 nm to 500 nm. The Y direction corresponds to the first direction.

[0046] The first light source 11 has a plurality of light sources 21 and the same number of parallelization elements 25 as the light sources 21. The plurality of light sources 21 are arranged at intervals along the X direction with the emission surfaces facing the +Y side, and are arranged at the same positions in the Y direction and the Z direction. The light source 21 emits blue light BL along the Y direction toward the +Y side. The blue light BL is diverged from the emission surface of the light source 21 with the Y direction as the center. The first light source 11 has, for example, four light sources 21. The number of light sources 21 included in the first light source 11 is appropriately set according to the ratio of the required amount of blue light BL emitted from the light source device 100 toward the color separation optical system 200 to the amount of blue light BL emitted from one light source 21. The light source 21 is, for example, a laser diode (LD) that emits blue light BL.

[0047] One parallelizing element 25 among the plurality of parallelizing elements 25 is configured in a manner corresponding to one of the plurality of light sources 21. One parallelizing element 25 is configured on the optical path of blue light BL emitted from one of the light sources 21. One parallelizing element 25 is configured at a position overlapping with one of the light sources 21 in the X direction and the Z direction, and at a position closer to the +Y side than one of the light sources 21 in the Y direction. The incident surface of the parallelizing element 25 is opposite to the emission surface of the light source 21. The parallelizing element 25 parallelizes the blue light BL emitted from the light source 21 in a radially divergent state with an optical axis parallel to the Y direction as the center, and emits the parallelized blue light BL toward the +Y side along the Y direction.

[0048] The parallelization element 25 is, for example, a plano-convex lens with a convex surface facing the emission side of the blue light BL. In addition, the parallelization element 25 is an optical element capable of parallelizing the incident blue light BL as described above, and is not limited to a plano-convex lens, and may be, for example, a biconvex lens, or an optical element other than a plano-convex lens or a biconvex lens.

[0049] In the first light source 11, one light source 21 and the parallelizing element 25 arranged corresponding to the light source 21 may be integrated into one package. In addition, a plurality of light sources 21 and a plurality of parallelizing elements 25 may be integrated and packaged on a substrate (not shown).

[0050] The beam expander 35 is arranged on the optical path of the blue light BL emitted from the first light source 11, at a position overlapping with one of the first light sources 11 in the X direction and the Z direction, and at a position closer to the +Y side than the first light source 11 in the Y direction. The beam expander 35 appropriately adjusts the beam widths of the blue light BL emitted from the first light source 11 in the X direction and the Z direction, so that the blue light BL with the adjusted beam width is emitted toward the +Y side along the Y direction. The beam widths of the blue light BL emitted from the beam expander 35 in the X direction and the Z direction are smaller than the beam widths of the blue light BL incident on the beam expander 35 in the same directions. Specifically, the beam width of the blue light BL emitted from the beam expander 35 is about the same as the beam width of the red light RL emitted from the second light source 12 described later.

[0051] The beam expander 35 has a focusing element 36 and a parallelizing element 37. The focusing element 36 focuses the parallel beams of the multiple blue lights BL emitted from the multiple parallelizing elements 25 of the first light source 11, and emits the blue lights BL focused in the X direction and the Z direction to the +Y side along the Y direction. The focusing element 36 is arranged on the optical path of the parallel beams of the multiple blue lights BL emitted from the multiple parallelizing elements 25 of the first light source 11, at a position overlapping with the area occupied by the multiple parallelizing elements 25 of the first light source 11 in the X direction and the Z direction, and at a position closer to the +Y side than the multiple parallelizing elements 25 in the Y direction. The focusing element 36 is, for example, a plano-convex lens with a convex surface facing the emission side of the blue lights BL, but may also be a biconvex lens or other optical lens capable of focusing the incident parallel beams of the multiple blue lights BL as described above.

[0052] The parallelizing element 37 is arranged on the optical path of the blue light BL emitted from the focusing element 36 and focused by the focusing element 36, and is arranged at a position overlapping with the focusing element 36 in the X direction and the Z direction, and is arranged at a position closer to the +Y side than the focusing element 36 in the Y direction. The parallelizing element 37 parallelizes the incident blue light BL and emits the parallelized blue light BL toward the +Y side along the Y direction. The parallelizing element 37 is, for example, a plano-concave lens with a concave surface facing the incident side of the blue light BL, but may also be an optical lens other than the plano-concave lens capable of parallelizing the incident blue light BL as described above.

[0053] The second light source 12 is arranged at a position closer to the -X side than the first light source 11. The second light source 12 emits red light RL of a red wavelength band including at least a wavelength belonging to red in the visible wavelength band toward the +Y side along the Y direction. The red light RL corresponds to the second light. The red wavelength band corresponds to the second wavelength band, which is different from the blue wavelength band, for example, a wavelength band of 610nm to 700nm.

[0054] The second light source 12 has a plurality of light sources 22 and the same number of parallelization elements 26 as the light sources 22. The plurality of light sources 22 are arranged at intervals along the X direction with the emission surface facing the +Y side, and are arranged at the same position as each other in the Y direction and the Z direction. The light source 22 emits red light RL along the Y direction toward the +Y side. The red light RL is diverged from the emission surface of the light source 22 with the Y direction as the center. The second light source 12 has, for example, two light sources 22. The number of light sources 22 included in the second light source 12 is appropriately set according to the ratio of the amount of red light RL required in the light source device 100 to the amount of red light RL emitted from one light source 22. The light source 22 is, for example, an LD that emits red light RL.

[0055] One parallelizing element 26 among the plurality of parallelizing elements 26 is configured in a manner corresponding to one of the plurality of light sources 22. One parallelizing element 26 is configured on the optical path of red light RL emitted from one of the light sources 22. One parallelizing element 26 is configured at a position overlapping with one of the light sources 22 in the X direction and the Z direction, and at a position closer to the +Y side than one of the light sources 22 in the Y direction. The incident surface of the parallelizing element 26 is opposite to the emission surface of the light source 22. The parallelizing element 26 parallelizes the red light RL emitted from the light source 22 in a radially divergent state with an optical axis parallel to the Y direction as the center, and emits the parallelized red light RL toward the +Y side along the Y direction.

[0056] The parallelization element 26 is, for example, a plano-convex lens with a convex surface facing the emission side of the red light RL. In addition, the parallelization element 26 is an optical element capable of parallelizing the incident red light RL as described above, and is not limited to a plano-convex lens, and may be, for example, a biconvex lens, or an optical element other than a plano-convex lens or a biconvex lens.

[0057] In the second light source 12, as in the first light source 11, one light source 22 and a parallelization element 26 arranged corresponding to the one light source 22 may be integrated into one package. In addition, a plurality of light sources 22 and a plurality of parallelization elements 26 may be integrated and packaged on a substrate not shown.

[0058] The reflective element 31 is arranged at a position overlapping with the second light source 12 in the X direction and the Z direction, and is arranged at a position closer to the +Y side than the beam expander 35 and the second light source 12 in the Y direction. The reflective element 31 reflects the red light RL incident from the -Y side along the Y direction, and emits the red light RL to the +X side along the X direction. The X direction corresponds to the second direction. The reflective element 31 is, for example, a total reflection mirror having a flat reflection surface. The reflection surface of the total reflection mirror constituting the reflective element 31 is arranged to be inclined relative to the X direction and the Y direction when viewed along the Z direction, and moves from the -Y side to the +Y side as it moves from the -X side to the +X side.

[0059] The optical path changing element 32 is arranged at a position where the optical path of the blue light BL emitted from the first light source 11 along the Y direction via the beam expander 35 intersects with the optical path of the red light RL emitted from the second light source 12 and reflected by the reflective element 31 along the X direction. The optical path changing element 32 makes the optical path of the blue light BL incident from the -Y side along the Y direction and the optical path of the red light RL incident from the -X side along the X direction coincide with each other. Figure 2 , at least the path and optical axis of the blue light BL at a stage subsequent to the beam expander 35, and the path and optical axis of the red light RL at a stage subsequent to the second light source 12 are shown. The optical path changing element 32 causes the incident blue light BL and red light RL to be emitted toward the +X side along the X direction, so that at least a portion of the optical path of the blue light BL and at least a portion of the optical path of the red light RL overlap with each other in the Y direction and the Z direction.

[0060] The optical path changing element 32 is, for example, a dichroic mirror having a flat reflecting surface. The reflecting surface of the dichroic mirror constituting the optical path changing element 32 reflects the blue light BL and allows the red light RL to pass through. The reflecting surface of the dichroic mirror is configured to be inclined relative to the X direction and the Y direction when viewed along the Z direction, and moves from the -Y side to the +Y side as it moves from the -X side to the +X side. In addition, the optical path changing element 32 is not limited to a dichroic mirror, and may be an optical element other than a dichroic mirror that can cause the blue light BL and the red light RL incident from different directions to be emitted toward the +X side along the same X direction as described above.

[0061] The uniformizing element 40 is disposed on the optical paths of the blue light BL and the red light RL emitted from the optical path changing element 32. The uniformizing element 40 corresponds to a uniformizing optical system, and uniformizes the intensity distribution of the incident blue light BL and the red light RL in the Y direction and the Z direction.

[0062] The uniformizing element 40 is composed of, for example, a double-sided lens array 41. The double-sided lens array 41 includes: a substrate having a plate surface parallel to the Y direction and the Z direction, a plurality of microlenses 42, and a number of microlenses 43 equal to the number of microlenses 42. The plurality of microlenses 42 and 43 divide the blue light BL and the red light RL emitted from the optical path changing element 32 into a plurality of small light beams in the Y direction and the Z direction. Figure 2 , the plurality of micro lenses 42 and 43 are illustrated in an enlarged manner, but the diameter of each micro lens 42 and 43 is sufficiently smaller than the beam width of the blue light BL and the red light RL.

[0063] A plurality of microlenses 42 are provided on the plate surface on the -X side of the substrate of the double-sided lens array 41. The plurality of microlenses 42 are adjacent to each other along the Y direction and the Z direction, and are arranged in a matrix in a plane including the Y direction and the Z direction. The microlens 42 is a plano-convex lens with a convex surface facing the incident side of the blue light BL and the red light RL. A plurality of microlenses 43 are provided on the plate surface on the +X side of the substrate of the double-sided lens array 41. The plurality of microlenses 43 are adjacent to each other along the Y direction and the Z direction, and are arranged in a matrix in a plane including the Y direction and the Z direction. One of the plurality of microlenses 43 is arranged in a manner corresponding to one of the plurality of microlenses 42 in the Y direction and the Z direction, and overlaps with the one microlens 42. The microlens 43 is a plano-convex lens with a convex surface facing the emission side of the blue light BL and the red light RL.

[0064] The light guide optical system 45 guides at least the blue light BL and the red light RL emitted from the optical path changing element 32 to the light conversion layer 61 of the wavelength conversion device 50A described later. The light guide optical system 45 also reflects the blue light BL and the red light RL emitted from the optical path changing element 32 to the +X side along the X direction and incident on the light guide optical system 45 from the -X side, and emits them to the +Y side along the Y direction. The light guide optical system 45 reflects the green light GL1 that diverges from the light conversion layer 61 with the X direction as the center and is emitted to the -X side and incident on the +X side, and emits them to the +Y side along the Y direction.

[0065] The light guide optical system 45 includes, for example, a dichroic mirror 71 having a flat reflection surface and a total reflection mirror 72 having a flat reflection surface. The dichroic mirror 71 is configured so that at least a portion of the reflection surface overlaps the optical path of the blue light BL and the red light RL emitted from the optical path changing element 32 and the optical path of the green light GL1 and GL2 emitted from the optical conversion layers 61 and 66 of the wavelength conversion device 50A described later. The dichroic mirror 71 corresponds to the first optical system. The dichroic mirror 71 transmits the blue light BL and the red light RL incident from the -X side and the +X side along the X direction and emits them to the +X side and the -X side. The dichroic mirror 71 reflects the green light GL1 and GL2 incident from the +X side along the X direction after being emitted from the optical conversion layers 61 and 66 of the wavelength conversion device 50A and emits them to the +Y side along the Y direction. The reflection surface of the dichroic mirror 71 reflects the green light GL1 and transmits the blue light BL and the red light RL. The reflecting surface of the dichroic mirror 71 is arranged to be inclined with respect to the X direction and the Y direction when viewed along the Z direction, and to move from the +Y side to the −Y side as it moves from the −X side to the +X side.

[0066] The total reflection mirror 72 is arranged at least at a position deviated from the optical path of the blue light BL and the red light RL emitted from the optical path changing element 32, for example, at a position closer to the +X side and the -Y side than the optical path changing element 32. On the other hand, the total reflection mirror 72 is arranged so that at least a part of the reflection surface overlaps with the optical path of the blue light BL and the red light RL emitted from the dichroic mirror 71 to the -X side along the X direction after passing through the dichroic mirror 71. The total reflection mirror 72 is arranged on the -X side opposite to the wavelength conversion device 50A arranged on the +X side with respect to the dichroic mirror 71. The total reflection mirror 72 is equivalent to the second optical system. The total reflection mirror 72 reflects the blue light BL and the red light RL incident from the +X side along the X direction after passing through the dichroic mirror 71, and emits them to the +Y side along the Y direction, so that the blue light BL and the red light RL overlap with the green light GL1 reflected by the dichroic mirror 71. The reflection surface of the total reflection mirror 72 reflects the blue light BL and the red light RL. The reflection surface of the total reflection mirror 72 is arranged to be inclined with respect to the X direction and the Y direction when viewed along the Z direction, and to move from the +Y side to the -Y side as it moves from the -X side to the +X side.

[0067] The lens 81 is arranged so as to overlap on the optical paths of the blue light BL and the red light RL emitted from the dichroic mirror 71 of the light guide optical system 45 and on the optical paths of the blue light BL, the red light RL, and the green light GL1 emitted from the wavelength conversion device 50A. The lens 81 is equivalent to a condensing optical system. The lens 81 deflects the blue light BL and the red light RL emitted from the dichroic mirror 71 through the dichroic mirror 71 of the light guide optical system 45, and enters from the -X side and converges to the wavelength conversion device 50A. The lens 81 collimates the green light GL1 emitted from the light conversion layers 61 and 66, and enters the dichroic mirror 71 from the +X side along the X direction.

[0068] Specifically, the lens 81 causes the blue light BL and the red light RL incident from the -X side along the X direction through the dichroic mirror 71 of the light guide optical system 45 to be emitted to the +X side and the -Y side, and converges toward the light conversion layer 61. At this time, the blue light BL and the red light RL are incident on the portion of the lens 81 that is closer to the +Y side than the central axis in the Y direction. The lens 81 parallelizes the blue light BL and the red light RL that are reflected by the wavelength selective reflection layers 63 and 64 of the wavelength conversion device 50A as described later and incident from the +X side and the +Y side, and emits them to the -X side along the X direction. At this time, the blue light BL and the red light RL are incident on the portion of the lens 81 that is closer to the -Y side than the central axis in the Y direction, that is, the position on the opposite side of the optical axis in the Y direction from when they were incident after passing through the dichroic mirror 71 of the light guide optical system 45. The optical path of the blue light BL and the red light RL emitted from the light guiding optical system 45 and reaching the wavelength conversion device 50A through the lens 81 from the −X side to the +X side is different from the optical path of the blue light BL and the red light RL emitted from the wavelength conversion device 50A and reaching the light guiding optical system 45 through the lens 81 from the +X side to the −X side.

[0069] In addition, the lens 81 is arranged on the optical path of the blue light BL, the red light RL, and the green light GL1 and GL2 between the light guide optical system 45 and the wavelength conversion device 50A in the X direction. The lens 81 parallelizes the green light GL1 and GL2 incident from the +X side in a divergent state with the X direction as the center, emits them to the -X side along the X direction, and enters the dichroic mirror 71 of the light guide optical system 45 from the +X side. The lens 81 is, for example, a biconvex lens, but it can also be an optical element other than the biconvex lens that can deflect and converge the blue light BL and the red light RL incident as described above, and can parallelize the green light GL1 and GL2 incident as described above.

[0070] The wavelength conversion device 50A is arranged at a position closer to the +X side than the lens 81, and is arranged at a position including the light guide optical system 45 and the lens 81 in the Y direction and the Z direction, reaching a position closer to the +Y side, the +Z side, and the -Z side than the light guide optical system 45 and the lens 81. The wavelength conversion device 50A includes, for example, a drive device 52, a substrate 54, a diffusion layer 60, light conversion layers 61 and 66, and wavelength selective reflection layers 63 and 64. The wavelength conversion device 50A is equivalent to a light conversion element. The wavelength conversion device 50A converts at least the incident blue light BL into yellow light YL in a yellow band different from the blue band. The yellow light YL is equivalent to the third light. The yellow band is equivalent to the third band, and includes the first green band and the red band in the green band. The green band includes at least a wavelength belonging to green in the visible band, for example, a band of 500nm to 600nm. The yellow light YL includes green light GL1 in the first green band and red light RF. The first green wavelength band is included in the green wavelength band, for example, a wavelength band of 550nm to 600nm. The red wavelength band of the red light RF included in the yellow light YL includes at least a wavelength belonging to red in the visible wavelength band, and may be the same as the red wavelength band emitted from the second light source 12, or may deviate from the red wavelength band emitted from the second light source 12 within the range belonging to red.

[0071] The substrate 54 has a plate surface parallel to the Y direction and the Z direction. The driving device 52 rotates the substrate 54 around the rotation axis JX. The driving device 52 is, for example, a motor, and has an axle component (not shown) with the rotation axis JX as the axis. The axle component of the driving device 52 is, for example, connected from the plate surface 54b on the +X side of the substrate 54 to the radial center of the substrate 54 with the rotation axis JX as the center. When observed along the X direction, the rotation axis JX coincides with the center of the plate surface of the substrate 54, and is located closer to the +Y side than the optical axes of the blue light BL and the red light RL emitted from the dichroic mirror 71 and the lens 81 of the light guide optical system 45. The substrate 54 is, for example, a metal circular plate. In addition, the material of the substrate 54 may be a resin with strength, etc., in addition to metal, and is not limited to a specific material.

[0072] Figure 3 1 is a schematic diagram of the wavelength conversion device 50A, and is a diagram of the wavelength conversion device 50A when viewed from the -X side along the X direction and the rotation axis JX. Figure 4 is a cross-sectional view of the wavelength conversion device 50A. Figure 3 The diagram is shown when viewed from the IV-IV line. Figure 5 is a cross-sectional view of the wavelength conversion device 50A. Figure 3 The figure is shown when viewed from the VV line. Figures 3 to 5 In the embodiment, the driving device 52 is omitted. Figures 3 to 5As shown, in the substrate 54, the plate surface 54a on the -X side into which the blue light BL emitted from the light guide optical system 45 and the lens 81 is incident is divided into a central portion, an inner peripheral portion on the outside of the central portion, and an outer peripheral end portion spaced apart from the inner peripheral portion in the radial direction centered on the rotation axis JX. In addition, the inner peripheral portion of the plate surface 54a of the substrate 54 is divided into a plurality of regions in the circumferential direction centered on the rotation axis JX, for example, into four regions in an angle range of 90°.

[0073] A reflective layer 55 is stacked on the entire surface 54a of the substrate 54. The reflective layer 55 reflects the incident blue light BL, green light GL1, and red light RF. Figure 2 The above are omitted in the schematic diagram showing the overall structure of the optical device.

[0074] The light conversion layer 61 is provided on the surface on the -X side of the reflective layer 55 stacked in one or more of the plurality of regions on the inner circumference of the plate surface 54a of the substrate 54, and is stacked on the reflective layer 55 in the X direction. The light conversion layer 61 is, for example, arranged in one of the four regions on the inner circumference of the plate surface 54a of the substrate 54. When the substrate 54 rotates in the circumferential direction around the rotation axis JX and the light conversion layer 61 reaches the -Y side, the center of the light conversion layer 61 in the Y direction and the Z direction substantially overlaps with the optical axes of the blue light BL and the red light RL emitted from the dichroic mirror 71 and the lens 81 of the light guide optical system 45.

[0075] The light conversion layer 61 converts the incident blue light BL into yellow light YL. The light conversion layer 61 corresponds to the first light conversion layer, and is excited by the blue light BL incident from the -X side to emit yellow light YL as fluorescence. The yellow light YL is emitted from the light conversion layer 61 to both the -X side and the +X side in a wide range radially with the X direction as the center. The light conversion layer 61 is formed of, for example, a fluorescent material containing cerium (Ce) that can be excited by the blue light BL to emit yellow light.

[0076] The wavelength selective reflection layer 64 is provided on the surface of the -X side of the light conversion layer 61 via the adhesive layer 65. The surface of the -X side of the light conversion layer 61 corresponds to the light incident surface. The adhesive layer 65 transmits light in the visible wavelength band. In addition, the wavelength selective reflection layer 64 may be laminated on the surface of the -X side of the light conversion layer 61, or the adhesive layer 65 may be omitted.

[0077] Figure 6: is a graph showing an example of the relative light intensity distribution of the yellow light YL emitted from the optical conversion layer 61 and the red light RL emitted from the second light source 12. The wavelength selective reflection layer 64 reflects the incident red light RL and the red light RF included in the yellow light YL. The wavelength selective reflection layer 64 is equivalent to the first wavelength selective reflection layer. The wavelength selective reflection layer 64 reflects the red light RL emitted from the second light source 12 and incident from the -X side and the +Y side toward the -X side and the -Y side, and diverges it. The wavelength selective reflection layer 64 reflects the red light RF incident from the +X side in the yellow light YL emitted from the optical conversion layer 61 toward the +X side, and transmits the green light GL1 included in the yellow light YL incident from the +X side and the blue light BL incident from the +X side and the -X side. The wavelength selective reflection layer 64 is based on Figure 6 The illustrated light intensity distribution of the yellow light YL and the red light RL is designed and is composed of a dielectric multilayer film capable of wavelength-selectively regular reflection of the red light RF and RL in the red wavelength band in the visible wavelength band.

[0078] Figure 7 is a graph showing an example of the reflectivity characteristics of the wavelength selective reflection layer 64. Figure 7 As shown, the wavelength selective reflection layer 64 may also reflect red light RF of a different wavelength band from the red light RL, and perform wavelength selective regular reflection only on the red light RL. In addition, since the red light RF included in the fluorescent yellow light YL has a smaller component on the wavelength side higher than 650nm, for example, the selective reflection layer 64 may also be able to transmit light of a wavelength band higher than 650nm.

[0079] The wavelength selective reflection layer 63 is provided in one of the multiple regions of the inner circumference of the plate surface 54a of the substrate 54, and more specifically, is provided on the surface of the -X side of the reflection layer 55 in the region that is separated from the region on which the light conversion layer 61 is stacked in the circumferential direction centered on the rotation axis JX among the multiple regions, and is stacked on the reflection layer 55 in the X direction. The wavelength selective reflection layer 63 reflects the incident blue light BL. The wavelength selective reflection layer 63 is equivalent to a reflection part. The wavelength selective reflection layer 63 reflects and scatters the blue light BL emitted from the first light source 11 and incident from the -X side and the +Y side to the -X side and the -Y side. The wavelength selective reflection layer 63 is composed of, for example, a dielectric multilayer film that can perform wavelength selective regular reflection of the blue light BL in the visible band.

[0080] The light conversion layer 66 is provided on the surface of the -X side of the reflective layer 55 stacked in the region between the region where the light conversion layer 61 is arranged in the circumferential direction centered on the rotation axis JX and the region where the wavelength selective reflective layer 63 is arranged, among the multiple regions of the inner circumference of the plate surface 54a of the substrate 54, and is stacked on the reflective layer 55 in the X direction. The light conversion layer 66 converts the incident blue light BL into the green light GL2 of the second green band in the green band. The light conversion layer 66 is equivalent to the second light conversion layer. The green light GL2 is equivalent to the fourth light. The second green band is included in the green band and is equivalent to the fourth band. The second green band may be the same as the first green band of the green light GL1 emitted from the light conversion layer 61, or may deviate from the first green band within the range belonging to green, for example, a band of 560nm to 600nm.

[0081] The light conversion layer 66 is excited by the blue light BL incident from the -X side and emits green light GL2 as fluorescence. The green light GL2 is emitted from the light conversion layer 66 radially to both the -X side and the +X side over a wide range with the X direction as the center. The light conversion layer 66 is formed of a fluorescent material including cerium (Ce) that can be excited by the blue light BL and emit the green light GL2.

[0082] The diffusion layer 60 is provided on the surface of the reflective layer 55 on the -X side of the entire circumferential direction around the rotation axis JX at the outer peripheral end of the plate surface 54a of the substrate 54 via the adhesive layer 65. The diffusion layer 60 extends outward from the outer peripheral end of the plate surface 54a of the substrate 54 in the radial direction around the rotation axis JX, and protrudes outward from the outer peripheral edges of the substrate 54 and the reflective layer 55 when viewed along the X direction and the rotation axis JX.

[0083] The diffusion layer 60 transmits the blue light BL, red light RL, and green light GL1 and GL2 emitted from the total reflection mirror 73 described later to the +X side along the X direction and incident from the -X side through the overlapping lens 82, and diffuses it within a plane including the Y direction and the Z direction. In the following description, the green light GL1 and GL2 are sometimes collectively referred to as the green light GL. The blue light BL, the red light RL, and the green light GL are diffused by the diffusion layer 60, thereby reducing the speckle of the image magnified and projected from the above-mentioned projection optical system 600 to the display surface of the screen SCR. The diffusion layer 60 is composed of, for example, a light diffusion element or a light diffusion material having a fine structure such as a concave-convex structure that is appropriately small relative to the wavelength bands of the blue light BL, the red light RL, and the green light GL formed on the surface of the -X side.

[0084] like Figure 2As shown, the total reflection mirror 73 is provided on the optical path of the blue light BL, the red light RL, and the green light GL1, GL2 emitted from the light guide optical system 45, and is arranged at a position overlapping with the dichroic mirror 71 of the light guide optical system 45 in the X direction and the Z direction, and is arranged at a position closer to the +Y side than the dichroic mirror 71, and is arranged at a position overlapping with the diffusion layer 60 of the wavelength conversion device 50A in the Y direction. The optical axis passing through the center of the Y direction and the Z direction of the region into which the blue light BL, the red light RL, and the green light GL1, GL2 are incident on the reflection surface of the total reflection mirror 73 passes through the approximate center in the Y direction of the diffusion layer 60 on the +Y side of the wavelength conversion device 50A, which extends to the +Y side, i.e., radially outward, relative to the substrate 54.

[0085] The total reflection mirror 73 has a flat reflection surface. The reflection surface of the total reflection mirror 73 is arranged to be inclined with respect to the X direction and the Y direction when viewed along the Z direction, and moves from the -Y side to the +Y side as it moves from the -X side to the +X side.

[0086] The total reflection mirror 73 reflects the green light GL1 and GL2 emitted from the dichroic mirror 71 of the light guide optical system 45 and the blue light BL and the red light RL emitted from the total reflection mirror 72 toward the +X side, that is, the wavelength conversion device 50A side, along the X direction. The total reflection mirror 73 is equivalent to the third optical system. Specifically, the total reflection mirror 73 reflects the green light GL1 and GL2 emitted from the dichroic mirror 71 along the Y direction and incident from the -Y side, and emits them toward the +X side along the X direction. The total reflection mirror 73 reflects the blue light BL and the red light RL emitted from the total reflection mirror 72 along the Y direction and incident from the -Y side, and emits them toward the +X side along the X direction.

[0087] The superimposing lens 82 is disposed between the total reflection mirror 73 and the diffusion layer 60 on the +Y side of the wavelength conversion device 50A in the X direction, and is disposed at a position overlapping the total reflection mirror 73 in the Y direction and the Z direction. The center axis of the superimposing lens 82 in the Y direction substantially overlaps with the optical axes of the blue light BL, the red light RL, and the green light GL1 and GL2 emitted from the total reflection mirror 73 to the +X side.

[0088] The superimposing lens 82 converges the blue light BL and the red light RL emitted from the double-sided lens array 41 and respectively passing through the dichroic mirror 71, the lens 81, and the wavelength conversion device 50A of the light guide optical system 45 and emitted from the total reflection mirror 73, and the green light GL1 and GL2 generated by the multiple small light beams of the blue light BL and the red light RL, and emits them to the +X side along the X direction. The superimposing lens 82 cooperates with the multiple micro lenses 42 and 43 of the double-sided lens array 41 to make the blue light BL, the red light RL and the green light GL1 and GL2 overlap each other in the image forming area of ​​each of the above-mentioned light modulating devices 400R, 400G, and 400B or in the vicinity of the image forming area on the optical path of the color light. The superimposing lens 82 is, for example, a biconvex lens, but it can also be an optical element with a focusing function other than a biconvex lens, it can also be a plano-convex lens, and it can also be composed of a plurality of optical lenses.

[0089] The rod lens 85 is arranged at a position closer to the +X side than the diffusion layer 60 on the +Y side of the wavelength conversion device 50A in the X direction, and is arranged at a position overlapping with the total reflection mirror 73, the superimposing lens 82, and the diffusion layer 60 on the +Y side of the wavelength conversion device 50A in the Y direction and the Z direction. The axis of the rod lens 85 is parallel to the X direction, and substantially overlaps with the optical axes of the blue light BL, the red light RL, and the green light GL1 and GL2 emitted from the total reflection mirror 73, the superimposing lens 82, and the diffusion layer 60 on the +Y side of the wavelength conversion device 50A to the +X side, respectively.

[0090] The rod lens 85 diffuses the blue light BL, red light RL, and green light GL1, GL2 incident from the -X side from the diffusion layer 60 on the +Y side of the wavelength conversion device 50A toward the +X side with the X direction as the center and emits them in a diffused state in a plane including the Y direction and the Z direction, and propagates them toward the +X side along the axis, thereby making the light intensity distribution of the blue light BL, red light RL, and green light GL1, GL2 in the plane including the Y direction and the Z direction uniform. The rod lens 85 emits the uniformized blue light BL, red light RL, and green light GL1, GL2 from the end surface on the +X side toward the +X side along the X direction.

[0091] In the light source device 100 having the above structure, the plurality of light sources 21 of the first light source 11, the plurality of light sources 22 of the second light source 12, and the driving device 52 of the wavelength conversion device 50A are connected to a control device (not shown). The control device supplies an electrical signal of a predetermined voltage to the plurality of light sources 21 of the first light source 11, and supplies an electrical signal of a predetermined voltage to the plurality of light sources 22 of the second light source 12 at a predetermined lighting time. That is, the control device performs pulse control of the plurality of second light sources 12.

[0092] The control device supplies an electric signal to the plurality of light sources 21 and 22, and drives the drive device 52 of the wavelength conversion device 50A, so that the substrate 54 rotates around the rotation axis JX, and drives the light modulators 400R, 400G, and 400B. The control device synchronizes the emission of the blue light BL from the plurality of light sources 21, the emission of the red light RL from the plurality of light sources 22, and the rotation of the substrate 54, and makes the blue light BL emitted from the lens 81 and incident on the wavelength conversion device 50A to be incident on either of the light conversion layers 61 and 66 during the period when the power signal is supplied to the plurality of light sources 21 and the blue light BL is emitted from the plurality of light sources 21, and makes the red light RL emitted from the lens 81 and incident on the wavelength conversion device 50A to be incident on the wavelength selective reflection layer 64 during the lighting period when the power signal is supplied to the plurality of light sources 22 and the red light RL is emitted from the plurality of light sources 22. That is, the control device makes the timing of starting to emit the red light RL from the plurality of light sources 22 coincide with the timing of the red light RL incident from the lens 81 to the wavelength converter 50A being incident on one end of the circumference of the wavelength selective reflection layer 64 centered on the rotation axis JX. The control device makes the timing of stopping the emission of the red light RL from the plurality of light sources 22 coincide with the timing of the red light RL incident from the lens 81 to the wavelength converter 50A being incident on the other end of the circumference of the wavelength selective reflection layer 64.

[0093] The blue light BL emitted from the plurality of light sources 21 of the first light source 11 is collimated by the collimating element 25, and is collected into one light beam by the beam expander 35, and the beam width is appropriately adjusted. The blue light BL emitted from the beam expander 35 is reflected by the optical path changing element 32, emitted toward the +X side along the X direction, passes through the uniformizing element 40, and is further guided toward the +X side along the X direction through the dichroic mirror 71 of the light guiding optical system 45, and is incident on a portion closer to the +Y side than the central axis of the lens 81, and is converged by the lens 81 to the wavelength conversion device 50A.

[0094] The substrate 54 of the wavelength conversion device 50A is rotated circumferentially around the rotation axis JX by the driving device 52, whereby the blue light BL converged by the lens 81 is incident on the wavelength selective reflection layer 64, the light conversion layer 66, the wavelength selective reflection layer 63, and the light conversion layer 66 in chronological order from the -X side and the +Y side.

[0095] The blue light BL incident on the wavelength selective reflection layer 64 passes through the wavelength selective reflection layer 64 and the adhesive layer 65, and enters the light conversion layer 61. A portion of the blue light BL incident on the light conversion layer 61 from the -X side excites the light conversion layer 61, so that yellow light is emitted from the light conversion layer 61 to the -X side and the +X side. The yellow light has a Lambertian distribution with the X direction as a substantial center. The remaining at least a portion of the blue light BL incident on the light conversion layer 61 from the -X side passes through the light conversion layer 61. The yellow light and the blue light BL emitted from the light conversion layer 61 to the +X side are reflected by the reflection layer 55 to the -X side. A portion of the blue light BL reflected by the reflection layer 55 re-excites the light conversion layer 61 and is converted into yellow light. The yellow light reflected by the reflection layer 55 is emitted to the -X side, sequentially passes through the light conversion layer 61 and the adhesive layer 65, and enters the wavelength selective reflection layer 64 from the +X side. The green light GL1 included in the yellow light YL emitted from the light conversion layer 61 and incident on the wavelength selective reflection layer 64 from the +X side passes through the wavelength selective reflection layer 64 and is emitted toward the -X side of the wavelength selective reflection layer 64. The red light RF included in the yellow light YL incident on the wavelength selective reflection layer 64 from the +X side is reflected by the wavelength selective reflection layer 64 and is not emitted from the wavelength conversion device 50A.

[0096] A portion of the blue light BL incident on the light conversion layer 66 excites the light conversion layer 66, causing the green light GL2 to be emitted from the light conversion layer 66 to the -X side and the +X side. The green light GL2 also has a Lambertian distribution approximately centered in the X direction, similarly to the yellow light YL. The remaining at least a portion of the blue light BL incident on the light conversion layer 66 from the -X side passes through the light conversion layer 66 and is reflected by the reflection layer 55 to the -X side. At least a portion of the blue light BL reflected by the reflection layer 55 excites the light conversion layer 66 again and is converted into the green light GL2. The green light GL2 reflected by the reflection layer 55 passes through the light conversion layer 66 and is emitted to the -X side.

[0097] As a result, during the time period when the blue light BL is incident on the wavelength selective reflection layer 64 and the light conversion layer 61, only the green light GL1 is emitted from the wavelength selective reflection layer 64 with the X direction as the center and toward the -X side at a greater divergence angle than the blue light BL and is diverged. During the time period when the blue light BL is incident on the light conversion layer 66, only the green light GL2 is emitted from the light conversion layer 66 with the X direction as the center and toward the -X side at a greater divergence angle than the blue light BL and is diverged.

[0098] The blue light BL incident on the wavelength selective reflection layer 63 is reflected, emitted to the -X side and the -Y side from the wavelength selective reflection layer 63, and diverges. That is, during the time period when the blue light BL is incident on the wavelength selective reflection layer 63, only the blue light BL is emitted to the -X side and the -Y side from the wavelength selective reflection layer 63.

[0099] According to the above-mentioned operating principle, the wavelength conversion device 50A causes the blue light BL to be always emitted divergently toward the -X side and the -Y side during the period when the blue light BL is emitted from the multiple light sources 21 of the first light source 11, and causes the green light GL to be emitted divergently toward the -X side with a divergence angle larger than that of the blue light BL with the X direction as the center during a specified time period.

[0100] The blue light BL emitted from the wavelength conversion device 50A is incident on the portion closer to the -Y side than the central axis of the lens 81, and is emitted to the -X side in parallel along the X direction, passes through the dichroic mirror 71 of the light guide optical system 45, is reflected by the total reflection mirror 72, and is emitted from the total reflection mirror 72 to the +Y side in the Y direction. The green light GL1 and GL2 emitted from the wavelength conversion device 50A are incident on the -Y side and the +Y side relative to the central axis of the lens 81, and are emitted to the -X side in parallel along the X direction, and have a larger beam width than the blue light BL in the Y direction and the Z direction. The green light GL1 and GL2 emitted from the lens 81 to the -X side are reflected by the dichroic mirror 71, and are emitted from the dichroic mirror 71 to the +Y side in the Y direction. The optical path of the green light GL emitted to the +Y side in the Y direction through the light guide optical system 45 overlaps with the optical path of the blue light BL. In addition, "overlapping with the optical path" refers to a state in which at least a part of the light beams forming each other's color light are on the same optical path.

[0101] The blue light BL and the green light GL1 and GL2 emitted from the light guide optical system 45 to the +Y side along the Y direction are reflected by the total reflection mirror 73, emitted from the total reflection mirror 73 to the +X side along the X direction, converged by the superimposing lens 82, diffused by the diffusion layer 60 arranged in the wavelength conversion device 50A, and diverged again, and are incident on the rod lens 85. Figure 1 The control device drives the light modulator 400B in a time period when at least the blue light BL is incident from the light source device 100, and converts the blue light BL into blue image light as described above. The control device drives the light modulator 400G in a time period when at least the green light GL1 and GL2 are incident from the light source device 100 as the green light GL, and converts the green light GL into green image light as described above.

[0102] Furthermore, the red light RL emitted from the plurality of light sources 22 of the second light source 12 is collimated by the collimating element 26, reflected by the reflecting element 31, emitted toward the +X side along the X direction, passes through the optical path changing element 32 and merges with the optical path of the blue light BL, and is emitted toward the +X side along the X direction from the optical path changing element 32. The red light RL emitted from the optical path changing element 32 passes through the uniformizing element 40. The optical path and behavior of the red light RL emitted from the uniformizing element 40 and incident on the wavelength conversion device 50A are the same as those of the blue light BL in the same range.

[0103] The substrate 54 of the wavelength conversion device 50A is rotated in the circumferential direction around the rotation axis JX by the driving device 52, and the rotation of the substrate 54 is synchronized with the lighting of the red light RL from the second light source 12, so that the red light RL focused by the lens 81 is incident on the wavelength selective reflection layer 64 from the -X side and the +Y side. The red light RL incident on the wavelength selective reflection layer 64 is reflected, emitted from the wavelength selective reflection layer 64 to the -X side and the -Y side, and diverges.

[0104] When the rotation speed of the substrate 54 based on the driving device 52 about the rotation axis JX is, for example, T0 [seconds / cycle], and the plate surface 54a of the substrate 54 is equally divided into four regions in the circumferential direction as described above, the time periods of the green light GL1 and GL2 emitted from the wavelength conversion device 50A at one time, that is, the prescribed emission time of the green light GL1 and GL2, are T0×(1 / 4) [seconds], and the time when neither the green light GL1 nor the green light GL2 is emitted is T0×(1 / 4) [seconds]. Under the same circumstances, the time period of the red light RL emitted from the wavelength conversion device 50A at one time, that is, the prescribed emission time of the red light RL, is T0×(1 / 4) [seconds], and the time when the red light RL is not emitted is T0×(3 / 4) [seconds]. The timing and time period of emitting the red light RL are consistent with the timing and time period of emitting the green light GL1, but are different from the timing and time period of emitting the green light GL2. When the substrate 54 rotates once, the wavelength conversion device 50A emits red light RL and green light GL1 during T0×(1 / 4)[seconds], then emits green light GL2 during T0×(1 / 4)[seconds], then emits blue light BL during T0×(1 / 4)[seconds], and then emits green light GL2 again during T0×(1 / 4)[seconds]. In the control device, the above-mentioned lighting times, conditions of the electrical signals supplied to the plurality of light sources 21 of the first light source 11 and the plurality of light sources 22 of the second light source 12, etc. are adjusted and appropriately set according to the light amounts required for the blue light BL, green light GL, and red light RL emitted from the light source device 100 and the light amount ratio in the color light.

[0105] The wavelength conversion device 50A is incident on the Figure 1 The optical path and behavior of the red light RL from the color separation optical system 200 are the same as those of the blue light BL in the same range. The control device drives the light modulator 400R during the time period when at least the red light RL is incident from the light source device 100, and converts the red light RL into red image light as described above.

[0106] The light source device 100 of the first embodiment described above has at least the first light source 11, the second light source 12, the wavelength conversion device (optical conversion element) 50A, the optical path changing element 32, and the light guiding optical system 45. The first light source 11 emits blue light (first light) BL in a blue wavelength band (first wavelength band). The second light source 12 emits red light (second light) RL in a red wavelength band (second wavelength band) different from the blue wavelength band. The wavelength conversion device 50 converts the incident blue light BL into yellow light (third light) YL in a yellow wavelength band (third wavelength band) different from the blue wavelength band. The optical path changing element 32 makes the optical path of the blue light BL emitted from the first light source 11 and incident from the -Y side along the Y direction (first direction) and the optical path of the red light RL emitted from the second light source 12 and incident from the -X side along the X direction (second direction) intersecting the Y direction coincide with each other. In the first embodiment, the optical path of the blue light BL and the optical path of the red light RL at the subsequent stage of the optical path changing element 32 completely overlaps with the optical path of the other in the Y direction and the Z direction, or is included in the optical path of the other. However, a state where a part of the optical path of the blue light BL overlaps with a part of the optical path of the red light RL in the Y direction and the Z direction, a state where the optical path of the blue light BL and the optical path of the red light RL do not overlap with each other in the Y direction and the Z direction but are formed in parallel along the X direction, and a state where the optical path of the blue light BL and the optical path of the red light RL are switched in time series in each of the above states are all included in the optical path of the blue light BL incident from the -Y side and the optical path of the red light RL incident from the -X side being made consistent with each other by the optical path changing element 32. The light guiding optical system 45 guides the blue light BL and the red light RL emitted from the optical path changing element 32 to the +X side along the X direction to the wavelength conversion device 50A. In the light source device 100 of the first embodiment, the light guiding optical system 45 reflects the green light GL1 and the green light GL2 of the blue light BL, the red light RL, the yellow light YL emitted from the wavelength converter 50A to the -X side, for example, to the +Y side different from the +X side toward the wavelength converter 50A.

[0107] In the light source device 100 of the first embodiment, the optical path of the blue light BL and the optical path of the red light RL from the light guide optical system 45 to the wavelength conversion device 50A are made to coincide with each other by the light guide optical system 45, so that the first light source 11 and the second light source 12 can be separated from each other, and the first light source 11 and the second light source 12 can be arranged on the -X side with respect to the light guide optical system 45. In the light source device 100 of the first embodiment, one optical path changing element 32 changes the optical path of the blue light BL from the Y direction to the X direction, and makes the optical path of the blue light BL and the optical path of the red light RL coincide with each other, so that it can be miniaturized compared with the conventional light source device. Therefore, according to the light source device 100 of the first embodiment, the first light source 11 that emits the blue light BL as the excitation light that can excite the phosphor that has the wavelength conversion function of the wavelength conversion device 50A and the second light source that emits the red light RL as the color light different from the blue light BL can reduce the number of components and suppress the size. Furthermore, according to the light source device 100 of the first embodiment, it is possible to suppress the loss of the red light RF included in the yellow light YL emitted from the light conversion layer 61 of the wavelength conversion device 50A.

[0108] In the light source device 100 of the first embodiment, the wavelength conversion device 50A includes a substrate 54, a light conversion layer (first light conversion layer) 61, and a wavelength selective reflection layer (first wavelength selective reflection layer) 64. The substrate 54 includes a reflection layer 55 that reflects at least blue light BL. The light conversion layer 61 is disposed on the reflection layer 55, and converts the incident blue light BL into yellow light YL including green light GL1 in the first green wavelength band and red light RF in the red wavelength band. The wavelength selective reflection layer 64 is disposed on the surface (light incident surface) on the -X side of the light conversion layer 61, and reflects the red light RL and RF.

[0109] In the light source device 100 of the first embodiment, the blue light BL is regularly reflected on the reflective layer 55, and the red light RL is regularly reflected on the wavelength selective reflective layer 64, so that when the blue light BL and the red light RL are incident from a direction inclined relative to a direction perpendicular to the surface of each reflective layer, they can be emitted in a direction different from that when they are incident. According to the light source device 100 of the first embodiment, the optical path of the blue light BL and the red light RL when they are emitted from the wavelength conversion device 50A and the optical path when they are incident on the wavelength conversion device 50A can be easily offset.

[0110] In the light source device 100 of the first embodiment, the light guide optical system 45 includes a dichroic mirror (first optical system) 71 and a total reflection mirror (second optical system) 72. The dichroic mirror 71 reflects the green light GL emitted from the wavelength conversion device 50A. The total reflection mirror 72 reflects the blue light BL and the red light RL to an optical path overlapping with the green light GL reflected by the dichroic mirror 71.

[0111] In the light source device 100 of the first embodiment, the optical paths of the blue light BL, the red light RL, and the green light GL are overlapped by the total reflection mirror 72 arranged separately from the dichroic mirror 71, thereby suppressing the size increase and easily controlling the illumination distribution of the color light at the subsequent stage of the light guide optical system 45.

[0112] In the light source device 100 according to the first embodiment, the total reflection mirror 72 is arranged on the side opposite to the wavelength conversion device 50A with respect to the dichroic mirror 71 .

[0113] In the light source device 100 of the first embodiment, the total reflection mirror 72 is arranged on the side opposite to the wavelength conversion device 50A in the X direction relative to the dichroic mirror 71, for example, on the -X side, so that the total reflection mirror 72 that does not transmit the green light GL but reflects it can be used as the second optical system. According to the light source device 100 of the first embodiment, the second optical system can be simply configured.

[0114] The light source device 100 of the first embodiment further includes a lens (condensing optical system) 81 disposed on the optical path of the blue light BL and the red light RL between the light guide optical system 45 and the wavelength conversion device 50A. The lens 81 allows the blue light BL and the red light RL that have passed through the light guide optical system 45 to be incident on the wavelength conversion device 50A, and allows the colored light emitted from the wavelength conversion device 50A to be incident on the light guide optical system 45. In the light source device 100 of the first embodiment, the blue light BL and the red light RL that have passed through the light guide optical system 45 are incident on a position of the lens 81 that is away from the central axis in the Y direction, that is, a position that is away from the central axis in the radial direction of the lens 81.

[0115] In the light source device 100 of the first embodiment, the blue light BL and the red light RL are incident on a portion separated from the central axis of the lens 81, that is, the optical axis of the color light, in the Y direction, for example, on the +Y side, when incident from the light guide optical system 45, and the blue light BL and the red light RL are incident on a portion on the opposite side of the central axis of the lens 81 in the Y direction from the light guide optical system 45, for example, on the -Y side, when incident from the wavelength conversion device 50A. According to the light source device 100 of the first embodiment, the optical paths of the blue light BL and the red light RL when incident from the light guide optical system 45 to the lens 81 are made different from the optical paths of the blue light BL and the red light RL when incident from the wavelength conversion device 50A to the lens 81, and it is possible to easily avoid the blue light BL and the red light RL emitted from the wavelength conversion device 50A from propagating toward the first light source 11 and the second light source 12.

[0116] In the light source device 100 of the first embodiment, the wavelength conversion device 50A includes a wavelength selective reflection layer (reflection portion) 63 that reflects blue light BL. The substrate 54 is a circular plate made of metal. The wavelength selective reflection layer 63 and the light conversion layer 61 are arranged in different regions in the circumferential direction around the rotation axis JX of the circular plate constituting the substrate 54.

[0117] In the light source device 100 of the first embodiment, a wavelength selective reflection layer 63 that reflects blue light BL is arranged in the wavelength conversion device 50A. Therefore, by adjusting the size of the wavelength selective reflection layer 63 in the circumferential direction, the light amount of blue light BL emitted from the wavelength conversion device 50A can be easily adjusted.

[0118] In the light source device 100 of the first embodiment, the wavelength conversion device 50A further includes a light conversion layer (second light conversion layer) 66. The light conversion layer 66 converts the incident blue light BL into green light (fourth light) GL2 of a green band (fourth band) included in a yellow band that is different from the blue band and the red band and is equivalent to the third band. The light conversion layer 66 is arranged on the reflection layer 55, and the light conversion layer 61 and the wavelength selective reflection layer 63 are arranged in different regions in the circumferential direction of the substrate 54.

[0119] In the light source device 100 of the first embodiment, the wavelength conversion device 50A also has a light conversion layer 66 that is excited by the blue light BL and emits green light GL. Therefore, the light amount of the green light GL emitted from the wavelength conversion device 50A can be increased, and the color gamut of the colored light emitted from the subsequent rod lens 85 can be expanded.

[0120] The light source device 100 of the first embodiment further includes a total reflection mirror (third optical system) 73. The total reflection mirror 73 reflects the colored light including the blue light BL, the red light RL, and the green light GL emitted from the light guide optical system 45 toward the +X side, that is, the wavelength conversion device 50A side in the X direction.

[0121] In the light source device 100 of the first embodiment, the colored light emitted from the wavelength conversion device 50A to the -X side and reflected to the +Y side by the light guiding optical system 45 is guided to the +X side toward the wavelength conversion device 50A by the total reflection mirror 73. Therefore, the optical path of the colored light is folded back, which can at least suppress the enlargement in the X direction.

[0122] In the light source device 100 of the first embodiment, the wavelength conversion device 50A has a diffusion layer 60. The diffusion layer 60 is provided at a region (position) different from the inner peripheral portion where the light conversion layer 61 is provided, that is, at the outer peripheral end portion in the radial direction centered on the rotation axis JX of the substrate 54. The diffusion layer 60 transmits and diffuses the colored light (light) including the blue light BL, the red light RL, and the green light GL emitted from the total reflection mirror 73.

[0123] In the light source device 100 of the first embodiment, the diffusion layer 60 extends radially outward from the outer peripheral end of the plate surface 54a of the substrate 54, that is, radially outward from the substrate 54. According to the light source device 100 of the first embodiment, one wavelength conversion device 50A has both the light conversion function of converting the blue light BL into the green light GL and the light diffusion function of diffusing the colored light in a plane including the Y direction and the Z direction, so the number of components can be reduced and miniaturization can be achieved.

[0124] The light source device 100 of the first embodiment further includes a uniformizing element (uniformizing optical system) 40. The uniformizing element 40 is disposed between the optical path changing element 32 and the light guiding optical system 45 on the optical paths of the blue light BL and the red light RL, and uniformizes the illuminance distribution of the blue light BL and the red light RL.

[0125] In the light source device 100 of the first embodiment, the illuminance distribution in a plane orthogonal to the optical axes of the blue light BL and the red light RL is uniformized by the uniformizing element 40, which can suppress color unevenness in the subsequent colored light of the light source device 100 and illuminance unevenness in the image when the colored light is converted into image light.

[0126] The light source device 100 of the first embodiment further includes a rod lens 85. The rod lens 85 makes uniform the light intensity distribution of the colored light (light) transmitted through the diffusion layer 60 of the wavelength conversion device 50A in a plane intersecting the optical axis, for example, in a plane including the Y direction and the Z direction.

[0127] In the light source device 100 of the first embodiment, the illuminance distribution of the colored light can be easily made uniform by the rod lens 85 disposed at the last stage on the optical paths of the blue light BL, the red light RL, and the green light GL.

[0128] The projector 10 of the first embodiment includes the light source device 100 of the first embodiment, light modulators 400R, 400G, 400B, and a projection optical system 600. The light modulators 400R, 400G, 400B modulate the red light (light) RL, green light (light) GL, and blue light (light) BL emitted from the light source device 100 according to image information, convert them into image lights of respective colors, and emit them. The projection optical system 600 projects the image lights of respective colors emitted from the light modulators 400R, 400G, 400B.

[0129] According to the projector 10 of the first embodiment, even if the light source device 100 includes a phosphor of a wavelength conversion device, namely a light conversion layer 61, a first light source 11 that emits blue light BL as excitation light that can excite the phosphor, and a second light source that emits red light RL as a color light different from the blue light BL, it is possible to suppress enlargement.

[0130] Second Embodiment

[0131] Next, refer to Figures 8 to 11 A projector and a light source device according to a second embodiment of the present invention are described. In the description of the second embodiment and thereafter, the same contents as those in the first embodiment are omitted, and for the same structures as those in the projector 10 and the light source device 100 according to the first embodiment, the same reference numerals as those in the corresponding structures in the projector 10 and the light source device 100 are used. In the description of the second embodiment and each modified example, only the structures and contents different from those described in the first embodiment are described.

[0132] Although not shown in the drawings, the projector according to the second embodiment includes a light source device 102 according to the second embodiment described below, instead of the light source device 100 in the projector 10 according to the first embodiment.

[0133] Figure 8 FIG. 1 is a schematic diagram of a light source device 102 according to the second embodiment. Figure 8 As shown, the light source device 102 has a first light source 11, a beam expander 35, a second light source 12, a reflecting element 31, an optical path changing element 32, a uniformizing element 40, a light guiding optical system 45, a lens 81, a wavelength conversion device 50B, a total reflection mirror 73, an overlapping lens 82 and a rod lens 85, and also has a third light source 13 and a dichroic mirror 33.

[0134] In the light source device 102, the second light source 12 has a light source 22 and a parallelizing element 26. The number of light sources 22 and parallelizing elements 26 in the second light source 12 of the light source device 102 is different from that of the second light source 12 of the light source device 100, but as described in the first embodiment, it is possible to appropriately change them in consideration of the amount of red light RL emitted from the light source device 102 and the amount of red light RL emitted from the light source 22.

[0135] The third light source 13 is arranged between the first light source 11 and the second light source 12 in the X direction. The third light source 13 emits the green light GL3 of the third green band toward the +Y side along the Y direction. The green light GL3 emitted from the third light source 13 is equivalent to the fifth light. The third green band is included in the green band and is equivalent to the fifth band. In the second embodiment, it is assumed that the third green band is different from the second green band of the green light GL2 emitted from the light conversion layer 66, and is a band that does not overlap with the second green band, for example, a band of 520nm to 550nm. In addition, the third green band may partially overlap with the second green band within the range belonging to green.

[0136] The third light source 13 has one light source 23 and one parallelization element 27, which is the same number as the light source 23. The light source 23 is arranged so that the emission surface faces the +Y side. The light source 23 emits green light GL3 along the Y direction toward the +Y side. The green light GL3 diverges from the emission surface of the light source 23 with the Y direction as the center. The number of light sources 22 possessed by the third light source 13 is appropriately set by comprehensively considering the amount of light required for the green light GL in the light source device 102, the amount of light of the green light GL1, GL2, and GL3 generated by the wavelength conversion device 50B, the amount of light of the green light GL3 emitted from one light source 23, and the like. For example, the light source 23 is an LD that emits the green light GL3. Therefore, the third light source 13 may also have, for example, more than two light sources 23. In this case, the more than two light sources 23 may also be arranged at intervals along the X direction and configured at the same positions as each other in the Y direction and the Z direction.

[0137] The parallelizing element 27 is arranged on the optical path of the green light GL3 emitted from the light source 23. The parallelizing element 27 is arranged at a position overlapping with the light source 23 in the X direction and the Z direction, and at a position closer to the +Y side than the light source 23 in the Y direction. The incident surface of the parallelizing element 27 is opposite to the emission surface of the light source 23. The parallelizing element 27 parallelizes the green light GL3 emitted from the light source 23 in a radially divergent state with the optical axis parallel to the Y direction as the center, and emits the parallelized green light GL3 toward the +Y side along the Y direction. In addition, as described above, in the case where the third light source 13 has more than two light sources 23, the same number of parallelizing elements 26 as the light source 23 are arranged in a manner corresponding to the plurality of light sources 23.

[0138] The parallelization element 27 is, for example, a plano-convex lens with a convex surface facing the emission side of the green light GL3. In addition, the parallelization element 27 is an optical element capable of parallelizing the incident green light GL3 as described above, and is not limited to a plano-convex lens, for example, it may be a biconvex lens, or an optical element other than a plano-convex lens or a biconvex lens.

[0139] In addition, in the third light source 13, similarly to the first light source 11 and the second light source 12, one light source 23 and a parallelization element 27 arranged corresponding to the one light source 23 may be integrated into one package. In addition, a plurality of light sources 23 and a plurality of parallelization elements 27 may be integrated on a substrate (not shown) and packaged.

[0140] The dichroic mirror 33 is arranged at a position overlapping with the third light source 13 in the X direction and the Z direction, and is arranged at a position closer to the +Y side than the third light source 13 in the Y direction. In addition, the dichroic mirror 33 is arranged between the reflective element 31 and the optical path changing element 32 in the X direction, and is arranged at a position overlapping with the reflective element 31 and the optical path changing element 32 in the Y direction and the Z direction. That is, the dichroic mirror 33 is arranged at a position where the optical path of the green light GL3 emitted from the third light source 13 in the Y direction intersects with the optical path of the red light RL emitted from the second light source 12 and reflected by the reflective element 31 in the X direction.

[0141] The dichroic mirror 33 makes the optical path of the green light GL3 incident from the -Y side along the Y direction and the optical path of the red light RL incident from the -X side along the X direction coincide with each other. Figure 8 , at least the path and optical axis of the green light GL3 which is later than the third light source 13 are shown. The dichroic mirror 33 emits the incident green light GL3 and red light RL toward the +X side along the X direction, so that at least a portion of the optical path of the green light GL3 and at least a portion of the optical path of the red light RL overlap each other in the Y direction and the Z direction.

[0142] The flat reflection surface of the dichroic mirror 33 reflects the green light GL3 and transmits the red light RL. The reflection surface of the dichroic mirror is configured to be inclined relative to the X direction and the Y direction when viewed along the Z direction, and moves from the -Y side to the +Y side as it moves from the -X side to the +X side. In addition, instead of the dichroic mirror 33, an optical element other than the dichroic mirror that can make the green light GL3 and the red light RL incident from different directions be emitted toward the +X side along the same X direction as described above may be configured.

[0143] The dichroic mirror 71 reflects the green light GL1 and GL2 incident from the +X side along the X direction after being emitted from the light conversion layers 61 and 66 of the wavelength conversion device 50B, and emits the green light GL3 incident from the -X side and the +X side along the X direction to the +Y side. The dichroic mirror 71 transmits the green light GL3 incident from the -X side and the +X side along the X direction, and emits the green light GL3 to the +X side and the -X side. Fig. 9 : is a graph showing an example of the transmittance characteristic of the dichroic mirror 71 in the light source device 102 . Fig. 9 The peak wavelengths of the transmittance in the graph of correspond to the peak wavelength of the blue light BL, the peak wavelength of the green light GL3, and the peak wavelength of the red light RL in order from the low wavelength side. Fig. 9 As illustrated, the reflection surface of the dichroic mirror 71 reflects the green light GL1 and GL2 and transmits the blue light BL, the red light RL, and the green light GL3 having a wavelength band different from that of the green light GL1 and GL2 .

[0144] The total reflection mirror 72 reflects the blue light BL, the red light RL, and the green light GL3 that are incident from the +X side along the X direction through the dichroic mirror 71, and emits them to the +Y side along the Y direction, so that the blue light BL, the red light RL, and the green light GL3 overlap with the green light GL1 and GL2 reflected by the dichroic mirror 71. The reflection surface of the total reflection mirror 72 reflects the blue light BL, the red light RL, and the green light GL3.

[0145] The lens 81 is disposed not only on the optical path of the blue light BL and the red light RL emitted from the dichroic mirror 71 of the light guide optical system 45, but also on the optical path of the green light GL3 and on the optical paths of the blue light BL, the red light RL, and the green light GL3 emitted from the wavelength converter 50B. The lens 81 deflects the blue light BL, the red light RL, and the green light GL3 emitted from the dichroic mirror 71 through the dichroic mirror 71 of the light guide optical system 45, and converges the blue light BL and the red light RL on the wavelength converter 50B to enter from the -X side, and converges the blue light BL and the green light GL3 on the wavelength converter 50B to enter from the -X side.

[0146] Specifically, the lens 81 causes the blue light BL, the red light RL, and the green light GL3 incident from the -X side along the X direction through the dichroic mirror 71 of the light guide optical system 45 to be emitted to the +X side and the -Y side, and converged toward the light conversion layer 61. At this time, the blue light BL, the red light RL, and the green light GL3 are incident on the portion of the lens 81 that is closer to the +Y side than the center axis in the Y direction. The lens 81 parallelizes the blue light BL, the red light RL, and the green light GL3 incident from the +X side and the +Y side by reflection from the wavelength selective reflection layers 63, 64, and 68 of the wavelength conversion device 50B as described later, and emits them to the -X side along the X direction. At this time, the blue light BL, the red light RL, and the green light GL3 are incident on the portion of the lens 81 that is closer to the -Y side than the center axis in the Y direction. The optical paths of the blue light BL, red light RL and green light GL3 from the -X side to the +X side that are emitted from the light guiding optical system 45 and reach the wavelength conversion device 50B through the lens 81 are different from the optical paths of the blue light BL, red light RL and green light GL3 from the +X side to the -X side that are emitted from the wavelength conversion device 50B and reach the light guiding optical system 45 through the lens 81.

[0147] In the light source device 102, the wavelength conversion device 50B includes a driving device 52, a substrate 54, a diffusion layer 60, light conversion layers 61 and 66, wavelength selective reflection layers 63 and 64, and a wavelength selective reflection layer 68. The wavelength conversion device 50B corresponds to a light conversion element.

[0148] Fig.101 is a schematic diagram of the wavelength conversion device 50B of the light source device 102 , and is a diagram of the wavelength conversion device 50B when viewed from the −X side along the X direction and the rotation axis JX. Fig.11 yes Fig.10 The cross-sectional view of the wavelength conversion device 50B is Fig.10 The figure is shown when looking from the XI-XI line. Fig.10 and Fig.11 As shown, the wavelength selective reflection layer 68 is provided on the surface of the -X side of the light conversion layer 66 via the adhesive layer 65. The surface of the -X side of the light conversion layer 66 is equivalent to the light incident surface. In addition, the wavelength selective reflection layer 68 can be stacked on the surface of the -X side of the light conversion layer 66, or the adhesive layer 65 can be omitted. The wavelength selective reflection layer 68 reflects the green light GL3 emitted from the third light source 13 and incident on the wavelength selective reflection layer 68. The wavelength selective reflection layer 68 is equivalent to the second wavelength selective reflection layer. The wavelength selective reflection layer 68 reflects and diverges the green light GL3 emitted from the third light source 13 and incident from the -X side and the +Y side to the -X side and the -Y side. The wavelength selective reflection layer 68 reflects the green light GL2 of the same wavelength band as the green light GL3 among the green light GL2 emitted from the light conversion layer 66 and incident from the +X side toward the +X side, and transmits the green light GL2 of the different wavelength band from the green light GL3 among the green light incident from the +X side and the blue light BL incident from the +X side and the -X side. The wavelength selective reflection layer 68 is composed of, for example, a dielectric multilayer film capable of wavelength selective regular reflection of the green light GL3 of the third green wavelength band among the light in the visible band.

[0149] The total reflection mirror 73 reflects the green light GL1 and GL2 emitted from the dichroic mirror 71 of the light guide optical system 45 and the blue light BL, red light RL, and green light GL3 emitted from the total reflection mirror 72 toward the +X side, that is, the wavelength conversion device 50B side, along the X direction. Specifically, the total reflection mirror 73 reflects the blue light BL, red light RL, and green light GL3 emitted from the total reflection mirror 72 along the Y direction and incident from the -Y side, and emits them toward the +X side along the X direction.

[0150] The superimposing lens 82 converges the blue light BL, the red light RL, and the green light GL3, which are emitted from the double-sided lens array 41 and respectively pass through the dichroic mirror 71, the lens 81, and the wavelength conversion device 50B of the light guide optical system 45 and are emitted from the total reflection mirror 73, and the green light GL1 and GL2 generated by the plurality of small light beams of the blue light BL, the red light RL, and the green light GL3, and emits them toward the +X side along the X direction. The superimposing lens 82 cooperates with the plurality of micro lenses 42 and 43 of the double-sided lens array 41 to overlap the blue light BL, the red light RL, and the green light GL1, GL2, and GL3 in the vicinity of the image forming areas of the above-mentioned light modulating devices 400R, 400G, and 400B or the image forming areas on the optical paths of the color lights.

[0151] The rod lens 85 diffuses the blue light BL, red light RL, and green light GL1, GL2 incident from the -X side toward the +X side with the X direction as the center and emits them in a diffused state in a plane including the Y direction and the Z direction, and propagates them toward the +X side along the axis line, thereby making the light intensity distribution of the blue light BL, red light RL, and green light GL1, GL2 in the plane including the Y direction and the Z direction uniform. The rod lens 85 emits the uniformized blue light BL, red light RL, and green light GL1, GL2 from the end surface on the +X side toward the +X side along the X direction.

[0152] In the light source device 102 having the above structure, the light source 23 of the third light source 13 is connected to a control device (not shown). The control device supplies an electric signal of a predetermined voltage to the plurality of light sources 21 of the first light source 11, supplies an electric signal of a predetermined voltage to the light source 22 of the second light source 12 at a predetermined lighting time, and supplies an electric signal of a predetermined voltage to the light source 23 of the third light source 13 at a predetermined lighting time. That is, the control device performs pulse control of the second light source 12 and the third light source 13.

[0153] The control device supplies electric signals to the plurality of light sources 21 and the light sources 22 and 23, and drives the driving device 52 of the wavelength conversion device 50B to rotate the substrate 54 around the rotation axis JX. The control device synchronizes the emission of the blue light BL from the plurality of light sources 21, the emission of the red light RL from the light source 22, the emission of the green light GL3 from the light source 23, and the rotation of the substrate 54. The control device supplies an electric signal to the light source 22 to cause the plurality of light sources 22 to emit the red light RL, and causes the red light RL emitted from the lens 81 and incident on the wavelength conversion device 50B to enter the wavelength selective reflection layer 64. The control device supplies an electric signal to the light source 23 to cause the green light GL3 emitted from the light source 23 to enter the wavelength selective reflection layer 68. The control device matches the timing at which the light source 23 starts emitting the green light GL3 with the timing at which the red light RL entering the wavelength converter 50B from the lens 81 enters one end of the wavelength selective reflection layer 68 in the circumferential direction around the rotation axis JX.

[0154] In the light source device 102, the optical path and behavior of the blue light BL and the red light RL after being emitted from the multiple light sources 21 of the first light source 11 to being emitted from the rod lens 85, and the optical path and behavior of the green light GL1 and GL2 after being emitted from the wavelength conversion device 50B to being emitted from the rod lens 85 are the same as the optical path and behavior of the various color lights of the light source device 100.

[0155] The green light GL3 emitted from the light source 23 of the third light source 13 is collimated by the collimating element 27, reflected by the dichroic mirror 33, emitted to the +X side along the X direction, passes through the optical path changing element 32 and merges with the optical paths of the blue light BL and the red light RL, and is emitted from the optical path changing element 32 to the +X side along the X direction. The green light GL3 emitted from the optical path changing element 32 passes through the uniformizing element 40. The optical path and behavior of the green light GL3 emitted from the uniformizing element 40 and incident on the wavelength conversion device 50B are the same as those of the blue light BL and the red light RL in the same range.

[0156] The substrate 54 of the wavelength conversion device 50B is rotated in the circumferential direction around the rotation axis JX by the driving device 52, and the rotation of the substrate 54 is synchronized with the lighting of the green light GL3 from the third light source 13, so that the green light GL3 focused by the lens 81 is incident on the wavelength selection reflection layer 68 from the -X side and the +Y side. The green light GL3 incident on the wavelength selection reflection layer 68 is reflected and emitted from the wavelength selection reflection layer 68 to the -X side and the -Y side to diverge.

[0157] In the light source device 102 of the second embodiment, similarly to the light source device 100 of the first embodiment, when the rotation speed of the substrate 54 of the driving device 52 about the rotation axis JX is, for example, T0 [seconds / turn], and when the plate surface 54a of the substrate 54 is equally divided into four regions in the circumferential direction, the time period of the green light GL3 emitted once from the wavelength conversion device 50B, that is, the prescribed emission time of the green light GL3 is T0×(1 / 4) [seconds], and the time period when the green light GL3 is not emitted is T0×(1 / 4) [seconds]. The timing and time period for emitting the green light GL3 are different from the timing and time period for emitting the red light RL. The green light GL3 is emitted twice when the substrate 54 rotates once. When the substrate 54 rotates once, the wavelength conversion device 50B emits blue light BL, red light RL and green light GL1 for a period of, for example, T0×(1 / 4) [seconds], then emits blue light BL and green light GL2 and GL3 for a period of T0×(1 / 4) [seconds], then emits only blue light BL for a period of T0×(1 / 4) [seconds], and again emits blue light BL and green light GL2 and GL3 for a period of T0×(1 / 4) [seconds]. In the control device, the lighting time of each color light, the conditions of the electric signal supplied to the plurality of light sources 21 of the first light source 11, the light source 22 of the second light source 12 and the light source 23 of the third light source 13, etc. are adjusted and appropriately set according to the light amount required for the blue light BL, green light GL1, GL2, GL3 and red light RL emitted from the light source device 102 and the light amount ratio in the color light.

[0158] The wavelength conversion device 50B is incident on the Figure 1The optical path and behavior of the green light GL3 to the color separation optical system 200 are the same as the optical paths and behaviors of the blue light BL and the red light RL in the same range.

[0159] The light source device 102 of the second embodiment described above has at least the first light source 11, the second light source 12, the wavelength conversion device (light conversion element) 50B, the optical path changing element 32, and the light guiding optical system 45. According to the light source device 102 of the second embodiment, even if the first light source 11 that emits blue light BL as excitation light that can excite the phosphor included in the wavelength conversion device 50B and the second light source that emits red light RL as a color light different from the blue light BL are included, it is possible to suppress the size increase. The light source device 102 of the second embodiment has the same structural elements and configuration structure as the light source device 100 of the first embodiment, and therefore has the same effects as the above-mentioned effects based on the same structural elements and configuration structure as the light source device 100 of the first embodiment.

[0160] The light source device 102 of the second embodiment further includes a third light source 13. The third light source 13 emits green light (fifth light) GL3 of the second green wavelength band (fifth wavelength band) included in the green wavelength band. In the light source device 102 of the second embodiment, the optical path changing element 32 makes the optical path of the green light GL3, the optical path of the blue light BL, and the optical path of the red light RL coincide with each other.

[0161] In the light source device 102 of the second embodiment, as a light source of colored light, in addition to the first light source 11 emitting blue light BL and the second light source 12 emitting red light RL, which are the same as the light source device 100 of the first embodiment, a third light source 13 emitting green light GL3 is used. According to the light source device 102 of the second embodiment, the optical path of the green light GL3 is made consistent with the optical path of the blue light BL and the optical path of the red light RL by using an optical path changing element 32, and therefore, compared with the light source device 100, the enlargement can be suppressed.

[0162] In the light source device 102 of the second embodiment, the wavelength conversion device 50B further includes a wavelength selective reflection layer (second wavelength selective reflection layer) 68. The wavelength selective reflection layer 68 is disposed on the surface (light incident surface) on the -X side of the light conversion layer (second light conversion layer) 66, and reflects the green light GL2.

[0163] In the light source device 102 of the second embodiment, the blue light BL is regularly reflected on the reflective layer 55, and the green light GL2 is regularly reflected on the wavelength selective reflective layer 68, so that when the blue light BL and the green light GL2 are incident from a direction inclined relative to a direction perpendicular to the surface of each reflective layer, they can be emitted in a direction different from that when they are incident. According to the light source device 102 of the second embodiment, the optical path of the blue light BL and the green light GL2 when emitted from the wavelength conversion device 50B can be easily offset from the optical path when incident on the wavelength conversion device 50B.

[0164] Modification of the Second Embodiment

[0165] Next, refer to Figures 12 to 15 A modification of the light source device 102 of the second embodiment will be described. The light source device 102 of the second embodiment may include a wavelength conversion device 50C described below instead of the wavelength conversion device 50B.

[0166] Fig.12 1 is a schematic diagram of the wavelength conversion device 50C, and is a diagram of the wavelength conversion device 50C when viewed from the -X side along the X direction and the rotation axis JX. Fig.13 is a cross-sectional view of the wavelength conversion device 50C. Fig.12 The diagram is shown when viewed from the XIII-XIII line. Fig.14 is a cross-sectional view of the wavelength conversion device 50C. Fig.12 The figure is a diagram of the case of viewing from the XIV-XIV line shown in FIG. Figure 12 to Figure 14 In the embodiment, the driving device 52 is omitted. Figure 12 to Figure 14 As shown, the wavelength conversion device 50C includes a driving device 52, a substrate 54, a diffusion layer 60, light conversion layers 61 and 66, wavelength selective reflection layers 63, 64 and 68, and color filter layers 62R and 62G. The wavelength conversion device 50C corresponds to a light conversion element.

[0167] In the wavelength conversion device 50C, the outer peripheral end of the plate surface 54a of the substrate 54 is divided into the same number of regions as the inner peripheral portion in the circumferential direction centered on the rotation axis JX, for example, divided into four regions within an angle range of 90°. The circumferential boundary lines of the regions of the outer peripheral end coincide with the circumferential boundary lines of the regions of the inner peripheral portion.

[0168] The color filter layer 62R is provided on the surface of the -X side of the diffusion layer 60 provided in a region which is point-symmetrical with respect to the region where the light conversion layer 61 and the wavelength selective reflection layer 64 are arranged, among a plurality of regions in the circumferential direction of the plate surface 54a of the substrate 54 centered on the rotation axis JX, and is stacked on the diffusion layer 60 in the X direction. The color filter layer 62R transmits the red light RL of the desired red wavelength band emitted from the light source device 102 in the red wavelength band, and absorbs or reflects the colored light other than the desired red wavelength band in the visible wavelength band. The color filter layer 62R is composed of, for example, a dichroic film which transmits the red light RL of the desired red wavelength band.

[0169] The color filter layer 62G is provided on the surface of the -X side of the diffusion layer 60 provided in a region which is point-symmetrical with respect to the region where the light conversion layer 66 and the wavelength selective reflection layer 68 are arranged, among a plurality of regions in the circumferential direction of the plate surface 54a of the substrate 54 centered on the rotation axis JX, and is stacked on the diffusion layer 60 in the X direction. The color filter layer 62G transmits the green light GL of the desired green wavelength band emitted from the light source device 102 in the second green wavelength band, and absorbs or reflects the color light other than the desired green wavelength band in the visible wavelength band. The color filter layer 62G is composed of, for example, a dichroic film which transmits the green light GL of the desired green wavelength band.

[0170] The color separation film constituting the color filter layers 62R and 62G can be formed directly on the surface of the -X side of the diffusion layer 60, or can be formed on the surface of a transparent substrate such as a glass substrate not shown, and can be bonded to the surface of the -X side of the diffusion layer 60 via an adhesive or the like as a stacked body with the transparent substrate.

[0171] In the case where the light source device 102 of the second embodiment has a wavelength conversion device 50C, the optical path and behavior of the blue light BL emitted from the first light source 11 and incident on the diffusion layer 60 of the wavelength conversion device 50C, the optical path and behavior of the red light RL emitted from the second light source 12 and incident on the diffusion layer 60 of the wavelength conversion device 50C, the optical path and behavior of the green light GL3 emitted from the third light source 13 and incident on the diffusion layer 60 of the wavelength conversion device 50C, and the optical paths and behaviors of the green lights GL1 and GL2 emitted from the optical conversion layers 61 and 66 of the wavelength conversion device 50C and incident on the diffusion layer 60 are the same as the respective optical paths and behaviors of the blue light BL, red light RL, green light GL1, GL2, and GL3 within the same range described in the second embodiment.

[0172] The blue light BL emitted from the total reflection mirror 73 toward the +X side in the X direction and condensed by the lens 82 is diffused by the diffusion layer 60 and diverges again, and enters the lens 85 through the rod lens 85. Figure 1 The color separation optical system 200 is shown in FIG.

[0173] Fig.15 This is a schematic diagram of a part of a modified example of the light source device 102, and is a diagram for explaining the optical paths and behaviors of the blue light BL, the green light GL1, GL2, GL3, and the red light RL from the wavelength conversion device 50C to the rod lens 85. Fig.15 In FIG. 8 , only the center and the optical axis of the colored light are shown, and the overlapping lens 82 is omitted. Fig.15 As shown, the red light RL emitted from the total reflection mirror 73 to the +X side along the X direction and condensed by the lens 82 passes through the color filter layer 62R and is converted into the red light RL of the desired red wavelength band among the incident red light RL. The red light RL of the desired red wavelength band is incident on the diffusion layer 60 from the -X side, diffused by the diffusion layer 60 and diverged again, and is emitted from the diffusion layer 60 to the +X side along the X direction, and is incident on the rod lens 85 through the rod lens 85. Figure 1 The color separation optical system 200 is shown in FIG.

[0174] The green light GL1 emitted from the total reflection mirror 73 to the +X side in the X direction and condensed by the lens 82 at the same timing and time period as the red light RL is absorbed or reflected by the color filter layer 62R.

[0175] The green light GL2 and GL3 emitted from the total reflection mirror 73 to the +X side along the X direction and condensed by the lens 82 pass through the color filter layer 62G and are converted into the green light GL of the desired green wavelength band among the incident green light GL2 and GL3. The green light GL of the desired green wavelength band is incident on the diffusion layer 60 from the -X side, diffused by the diffusion layer 60 and diverged again, and emitted from the diffusion layer 60 to the +X side along the X direction, and is incident on the rod lens 85 through the rod lens 85. Figure 1 The color separation optical system 200 is shown in FIG.

[0176] As a result, the blue light BL, the green light GL in the desired green wavelength band, the red light RL in the desired red wavelength band, and the green light GL in the desired green wavelength band are emitted from the rod lens 85 in a time series.

[0177] In a modification of the light source device 102 of the second embodiment, in the wavelength conversion device 50C, the color filter layers 62R and 62G are provided in a region (position) different from the light conversion layer 61 in the radial direction centered on the rotation axis JX of the substrate 54. The color filter layers 62R and 62G transmit only the red light RL of a desired red wavelength band (prescribed wavelength band) and the green light GL of a desired green wavelength band (prescribed wavelength band) among the colored light (light) including the blue light BL, the red light RL and the green light GL1, GL2 and GL3 emitted from the total reflection mirror (third optical system) 73.

[0178] In the modified example of the light source device 102 of the second embodiment, a wavelength conversion device 50C has a light conversion function of converting blue light BL into green light GL1, GL2, and a filtering function of filtering the red light RL of the desired red band and the green light GL of the green band that should be amplified and projected onto the screen SCR among the red light RL and the green light GL1, GL2. According to the modified example of the light source device 102 of the second embodiment, the number of components can be reduced and miniaturization can be achieved.

[0179] Modification of the first embodiment <1>

[0180] Next, a modification of the light source device 100 according to the first embodiment will be described. The light source device 100 according to the first embodiment may include a wavelength conversion device described below instead of the wavelength conversion device 50A.

[0181] Although not shown in the figure, a modified example of the first embodiment <1> The wavelength conversion device has a driving device 52, a substrate 54, a diffusion layer 60, light conversion layers 61, 66 and wavelength selective reflection layers 63, 64, 68, and also has a transparent substrate, which is equivalent to a light conversion element. <1> In the wavelength conversion device of the first embodiment, in the wavelength conversion device 50A of the first embodiment, a transparent substrate is provided in a region that is point-symmetrical with the region where the light conversion layer 66 is provided about the rotation axis JX in the radial range among a plurality of regions in the circumferential direction of the substrate 54 centered on the rotation axis JX, instead of the diffusion layer 60. The transparent substrate is formed of a material that transmits color light in the visible wavelength band, for example, an optical glass substrate. In the case where the transparent substrate is formed of optical glass, the diffusion layer 60 and the transparent substrate may be alternately connected in the circumferential direction of the substrate 54 centered on the rotation axis JX.

[0182] In the variant <1> In the wavelength conversion device of the embodiment, the optical path and behavior of the blue light BL emitted from the first light source 11 to the rod lens 85 are the same as the optical path and behavior of the blue light BL in the same range described in the second embodiment. The optical path and behavior of the red light RL emitted from the second light source 12 to the rod lens 85 and the optical path and behavior of the green light GL1 emitted from the light conversion layer 61 to the rod lens 85 are the same as the optical paths and behaviors of the red light RL and the green light GL1 in the same range described in the wavelength conversion device 50C of the modified example of the second embodiment.

[0183] In the variant <1> In the wavelength conversion device of the embodiment, the optical path and behavior of the green light GL2 emitted from the light conversion layer 66 to the lens 82 and converged by the lens 82 are the same as the optical path and behavior of the green light GL2 in the same range described in the first embodiment. <1> The wavelength conversion device of the transparent substrate is further diverged from the transparent substrate, passes through the rod lens 85, and is incident on Figure 1 The color separation optical system 200 is shown in FIG.

[0184] The uniformity of the light intensity distribution of the green light GL2 generated as fluorescence in a plane perpendicular to the optical axis is lower than the uniformity of the light intensity distribution of the blue light BL and the red light RL emitted from the LD in a plane perpendicular to the optical axis. Even if the green light GL2 passes through the transparent substrate instead of the diffusion layer 60, the green light GL having good uniformity is emitted from the rod lens 85 and enters the color separation optical system 200. According to the modification of the first embodiment <1> The light source device with the wavelength conversion device can obtain the same effects as the light source device 100 of the first embodiment.

[0185] Modification of the first embodiment <2>

[0186] Next, refer to Fig.16 and Fig.17 Other modifications of the light source device 100 according to the first embodiment will be described. Fig.16 A modification of the first embodiment <2> A schematic diagram of the light source device 104 is shown. Fig.16 As shown, the light source device 104 is provided with an optical element 171 described below, instead of the dichroic mirror 71 of the light guide optical system 45 in the light source device 100 of the first embodiment.

[0187] Fig.17 The front view of the optical element 171 is a view when the optical element 171 is viewed from the +X side and the +Y side toward the -X side and the -Y side. The optical element 171 corresponds to the first optical system and is composed of a substrate having a flat reflective surface. Fig.17 As shown, through holes H1 to H3 are formed in the optical element 171. The reflective surface of the optical element 171 is configured to be inclined relative to the X direction and the Y direction when viewed along the Z direction, and moves from the +Y side to the -Y side as it moves from the -X side to the +X side. The reflective surface of the optical element 171 reflects color light in the visible band. The reflective surface of the optical element 171 is composed of a dichroic film that can reflect the green light GL1 and GL2, for example.

[0188] The optical element 171 includes a plurality of regions AR1 to AR6. The region AR1 corresponds to the first region and is located between the incident region of the blue light BL and the red light RL reflected by the total reflection mirror 72 of the light guide optical system 45 and incident from the -Y side in the Y direction and the incident region of the blue light BL and the red light RL emitted from the uniformizing element 40 and incident from the -X side in the X direction in the Y direction in the Y direction. The region AR2 corresponds to the second region and is located between the incident region of the blue light BL and the red light RL emitted from the wavelength conversion device 50A and incident from the +X side in the X direction through the lens 81 and the incident region of the blue light BL and the red light RL reflected by the total reflection mirror 72 and incident from the -Y side in the Y direction in the Y direction. The region AR3 is located closer to the -Y side than the incident region of the blue light BL and the red light RL emitted from the wavelength conversion device 50A and incident from the +X side in the X direction through the lens 81.

[0189] The area AR4 corresponds to the fourth area and is an area located between the area AR1 and the area AR2 in the Y direction. The blue light BL and the red light RL reflected by the total reflection mirror 72 enter the area AR4 from the -Y side along the Y direction. The area AR5 corresponds to the fifth area and is an area located between the area AR2 and the area AR3 in the Y direction. The blue light BL and the red light RL emitted from the wavelength conversion device 50A and emitted along the X direction through the lens 81 enter the area AR5. The area AR6 includes an area where the blue light BL and the red light RL emitted from the uniformizing element 40 enter from the -X side along the X direction, and is located on the +Y side of the area AR1.

[0190] The through hole H1 is formed in the Y direction and the Z direction in the range including the incident region of the blue light BL and the red light RL emitted from the uniformizing element 40 in the region AR6. The through hole H2 is formed in the region AR4 in the range including the incident region in the Y direction of the blue light BL and the red light RL reflected by the total reflection mirror 72. The through hole H3 is formed in the range including the incident region of the blue light BL and the red light RL emitted from the wavelength conversion device 50A and incident from the +X side along the X direction toward the optical element 171 through the lens 81.

[0191] In the optical element 171, a reflective film 176 is provided in a region other than the region where the through holes H1 to H3 are formed in the plate surface of the substrate made of optical glass on the +X side, that is, outside the incident region of the blue light BL and the red light RL emitted from the wavelength converter 50A and then emitted from the lens 81 to the -X side along the X direction, outside the incident region of the blue light BL and the red light RL reflected by the total reflection mirror 72 and emitted to the +Y side along the Y direction, and outside the incident region of the blue light BL and the red light RL emitted from the uniformizing element 40 and incident from the -X side along the X direction. The reflective film 176 is, for example, a dichroic film that wavelength-selectively reflects the green light GL1 of the first green wavelength band and the green light GL2 of the second green wavelength band.

[0192] In the variant <2> In the light source device 104 of the embodiment, the optical path and behavior of the blue light BL from the first light source 11 to the rod lens 85, the optical path and behavior of the red light RL from the second light source 12 to the rod lens 85, and the optical paths and behaviors of the green light GL1 and GL2 from the wavelength conversion device 50A to the rod lens 85 are the same as the optical paths and behaviors of the blue light BL, the red light RL, and the green light GL1 and GL2 in the same range in the light source device 100 described in the first embodiment. However, at least a part of the green light GL1 and GL2 emitted from the wavelength conversion device 50A and emitted from the lens 81 is reflected by the reflection film 176 of the optical element 171 and emitted to the +Y side along the Y direction. The remaining part of the green light GL1 and GL2 passes through the through holes H1 to H3 and is emitted to the position closer to the -X side than the optical element 171, so it does not reach the rod lens 85 and becomes a loss.

[0193] According to the modification of the first embodiment <2> The light source device 104 of the first embodiment can obtain the same effects as the light source device 100 of the first embodiment.

[0194] In the modification of the first embodiment <2> In the light source device 104, the optical element (first optical system) 171 of the light guide optical system 45 has regions (first region to fifth region) AR1 to AR5 for reflecting the green light GL1 included in the yellow light (third light) YL. The region (fourth region) AR4 is located between the region AR1 (first region) and the region AR2 (second region) in the Y direction, and is arranged at the center of the optical element 171 in the Y direction. The region AR5 is arranged between the region AR2 and the region AR3 in the Y direction. In a modification of the first embodiment <2> In the light source device 104, the blue light BL and the red light RL emitted from the wavelength conversion device 50A pass through the through hole H3 formed in the area (fifth area) AR5. The blue light BL and the red light RL emitted from the total reflection mirror (second optical system) 72 of the light guide optical system 45 pass through the through hole H2 formed in the area (fourth area) AR4.

[0195] According to the modification of the first embodiment <2> The light source device 104 can make the centers of the green light GL1 and GL2 reflected by the reflection surface of the optical element 171 close to the centers of the blue light BL and the red light RL reflected by the reflection surface of the total reflection mirror 72. Thus, the size of the light source device 104 can be suppressed.

[0196] In the modification of the first embodiment <2> In the light source device 104 , the through hole H2 is formed in the region AR4 , the through hole H3 is formed in the region AR5 , and the through hole H1 is formed in the region AR6 .

[0197] According to the modification of the first embodiment <2> The light source device 104 can simply constitute the optical element 171 as the first optical system in the light guide optical system 45.

[0198] In the modification of the first embodiment <2> In the light source device 104, the optical element 171 has a first reflecting element 181 formed by the area AR1, a second reflecting element 182 formed by the area AR2, and a third reflecting element 183 formed by the area AR3 in the Y direction. The first reflecting element 181, the second reflecting element 182, and the third reflecting element 183 have a reflecting film 176 that reflects the green light GL1 of the yellow light (third light) YL emitted from the light conversion layer 61. In a modification of the first embodiment <2> In the light source device 104, the blue light BL and the red light RL emitted from the wavelength conversion device 50A pass between the second reflecting element 182 and the third reflecting element 183 in the Y direction, and specifically, pass through the through hole H3 formed in the area AR5 between the second reflecting element 182 and the third reflecting element 183. The blue light BL and the red light RL emitted from the total reflection mirror (second optical system) 72 pass between the first reflecting element 181 and the second reflecting element 182 in the Y direction, and specifically, pass through the through hole H2 formed in the area AR4 between the first reflecting element 181 and the second reflecting element 182.

[0199] According to the modification of the first embodiment <2> The light source device 104 can simply constitute the light guide optical system 45. <2> In the light source device 104, the arrangement of each reflective element can be appropriately adjusted so that the optical paths of the blue light BL and the red light RL emitted from the light guide optical system 45 coincide with the optical paths of the green lights GL1 and GL2.

[0200] In addition, as a further modification, the first optical element 181 and the second optical element 182 may be separated from each other in the Y direction. Similarly, the second optical element 182 and the third optical element 183 may be separated from each other in the Y direction. That is, the first optical element 181, the second optical element 182, and the third optical element 183 may be configured separately from each other.

[0201] Modification of the first embodiment <3>

[0202] Next, refer to Fig.18 and Fig.19 Another modification of the light source device 100 of the first embodiment will be described. Although not shown in the figure, the modification of the first embodiment <3> A modified example of the first embodiment in which the light source device is replaced <2> In addition to the optical element 171 of the light guide optical system 45 in the light source device 104, an optical element 172 described below is provided.

[0203] Fig.18 1 is a front view of the optical element 172, which is a view when the optical element 172 is viewed from the +X side and the +Y side toward the -X side and the -Y side. Fig.18As shown, a modification of the first embodiment <3> The optical element 172 is a modified example of the first embodiment. <2> The through holes H1 to H3 of the optical element 171 are provided with a wavelength selective transmission film 175. The wavelength selective transmission film 175 transmits the blue light BL in the blue wavelength band and the red light RL in the red wavelength band, and reflects the green light GL1 in the first green wavelength band and the green light GL2 in the second green wavelength band. Fig.19 : is a graph showing an example of the transmittance characteristics of the wavelength selection transmission film 175. Fig.19 As illustrated, the wavelength selective transmission film 175 is a dichroic film that selectively transmits the blue light BL and the red light RL in wavelength as described above.

[0204] In the modification of the first embodiment <3> In the light source device of the embodiment, the optical path and behavior of the blue light BL from the first light source 11 to the rod lens 85, the optical path and behavior of the red light RL from the second light source 12 to the rod lens 85, and the optical paths and behaviors of the green lights GL1 and GL2 from the wavelength conversion device 50A to the rod lens 85 are the same as the respective optical paths and behaviors of the blue light BL, the red light RL, the green light GL1 and GL2 in the same range in the light source device 100 described in the first embodiment. However, the blue light BL and the red light RL emitted from the wavelength conversion device 50A and emitted from the lens 81 pass through the wavelength selective transmission film 175, are emitted to the -X side of the optical element 171, are reflected by the total reflection mirror 72, and are emitted from the total reflection mirror 72 to the +Y side along the Y direction. At least a portion of the green light GL1 and GL2 emitted from the wavelength converter 50A and then emitted from the lens 81 is reflected by the reflective film 176 of the optical element 171 and emitted toward the +Y side along the Y direction. The remaining portion of the green light GL1 and GL2 is also reflected by the wavelength selective transmission film 175 and emitted toward the +Y side along the Y direction. <3> In the light source device, the green lights GL1 and GL2 incident on the wavelength selection transmission film 175 are also guided to the rod lens 85.

[0205] According to the modification of the first embodiment <3> The light source device can obtain the same effects as the light source device 100 of the first embodiment.

[0206] In the modification of the first embodiment <3> In the light source device, the yellow band (the third band) includes the green band (the second band). A wavelength selective transmission film 175 is disposed in the regions AR4 and AR5. The wavelength selective transmission film 175 transmits the blue light BL in the blue band and the red light RL in the red band (the second band) (a part of the light including the second band) of the color light (light) incident on the optical element 171 of the light guide optical system 45, and reflects the other color light (light), that is, the green light GL1 and GL2 in the green band.

[0207] According to the modification of the first embodiment <3> The wavelength selective transmission film 175 selectively transmits the incident blue light BL and red light RL and reflects the green light GL1 and GL2. <2> Compared with the light source device 104 , the loss of the green lights GL1 and GL2 in the light guide optical system 45 can be suppressed.

[0208] As mentioned above, although the preferred embodiment of the present invention is described in detail, the present invention is not limited to this specific embodiment, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims.

[0209] For example, the projectors of the above-mentioned embodiments and modified examples include a color separation optical system and three light modulators between the light source device and the projection optical system in the optical path of the color light and the image light of each color, but may be replaced by a light modulator having a red, green and blue color filter in each pixel, so as to be configured as a single-board projector. In addition, the projectors of the above-mentioned embodiments and modified examples may also include a light modulator composed of a DMD (Digital Micromirror Device) instead of the color separation optical system and the three light modulators.

[0210] Fig. 20 1 is a schematic diagram of a light source device 106 according to an example of the present invention, and is a schematic diagram of another modified example of the light source device 100 according to the first embodiment. Fig. 20As illustrated, the light source device of the present invention includes a light source device 106 of a simple structure, which has a first light source 11, a second light source 12, an optical path changing element 32, a wavelength conversion device (optical conversion element) 50D having a light conversion layer 61, a reflector 178 as a light guiding optical system 45, and a collimating lens 185. The light conversion layer 61 allows red light RL to pass through. The reflector 178 is configured in the same manner as the color separation mirror 71 so that the reflecting surface is inclined toward the X direction and the Y direction when observed along the Z direction. The reflector 178 allows the colored light incident from the -X side to pass through, and reflects the colored light incident from the +X side. The collimating lens 185 emits the colored light continuously emitted from the color separation mirror 71 to the +Y side, that is, the blue light BL, the red light RL, and the green light GL as white light WL. The white light WL is, for example, directed toward Figure 1 The color separation optical system 200 of the projector 10 emits.

[0211] In addition, the wavelength selective reflection layers 64 and 68 may be directly formed on the plate surface 54a of the substrate 54 made of optical glass such as BK7, and arranged between the substrate 54 and the light conversion layers 61 and 66 in the X direction. The wavelength selective reflection layers 64 and 68 may also be directly formed on the plate surface 54b of the substrate 54 made of optical glass such as BK7. In addition, the substrate 54 may also be composed of a diffusion plate having a diffusion angle of 1° to 5°, for example.

[0212] In the light source device 100 of the first embodiment, the light guide optical system 45 includes the first optical system 71 and the second optical system 72, but the light guide optical system 45 may be constituted by a single optical element. In this case, for example, the light guide optical system may be constituted so that only the region where the blue light BL and the red light RL are incident from the -X side along the X direction is constituted by a reflector having wavelength selectivity, so that the incident blue light BL and the red light RL are transmitted, and the other region is constituted by a reflector having reflection characteristics with respect to the entire wavelength band, so that the incident blue light BL and the red light RL are reflected.

[0213] In the light source device 102 of the second embodiment, the light guide optical system 45 includes the first optical system 71 and the second optical system 72, but the light guide optical system 45 may be constituted by a single optical element. In this case, for example, the light guide optical system may be constituted so that only the region where the blue light BL, the red light RL, and the green light GL3 are incident from the -X side along the X direction is constituted by a reflector having wavelength selectivity, so that the incident blue light BL, the red light RL, and the green light GL3 are transmitted, and the other region is constituted by a reflector having reflection characteristics with respect to the entire wavelength band, so that the incident blue light BL, the red light RL, and the green light GL3 are reflected.

[0214] Summary of the Disclosure

[0215] The following is a summary of the present disclosure.

[0216] (Supplementary Note 1) A light source device comprises: a first light source that emits a first light in a first wavelength band; a second light source that emits a second light in a second wavelength band different from the first wavelength band; a light conversion element that converts the incident first light into a third light in a third wavelength band different from the first wavelength band; an optical path changing element that makes the optical path of the first light emitted from the first light source and incident from a first direction consistent with the optical path of the second light emitted from the second light source and incident from a second direction intersecting the first direction; and a light guiding optical system that guides the first light and the second light emitted from the optical path changing element to the light conversion element, and the light guiding optical system reflects the first light, the second light and the third light emitted from the light conversion element.

[0217] According to the structure of Supplementary Note 1, after the second light and the third light are synthesized, the color light from the first light to the third light is made to reach the light conversion element along mutually consistent optical paths, so that the first light source and the second light source can be concentrated in separate areas, and the enlargement of the light source device can be suppressed. The optical path changing element has the functions of synthesizing the first light and the second light and changing the optical path of the second light, which can contribute to miniaturization.

[0218] (Note 2) According to the light source device described in Note 1, the light conversion element comprises: a substrate having a reflective layer; a first light conversion layer arranged on the reflective layer and converting the incident first light into the third light; and a first wavelength selective reflective layer arranged on the light incident surface of the first light conversion layer and reflecting the second light.

[0219] According to the structure of Supplementary Note 2, the second light can be regularly reflected on the first wavelength selective reflection layer, i.e., on the light incident side, so that the incident optical paths of the first light and the second light to the light conversion element and the outgoing optical paths from the light conversion element are different from each other.

[0220] (Note 3) A light source device according to Note 2, wherein the light-guiding optical system comprises a first optical system and a second optical system, the first optical system reflects the third light emitted from the light conversion element, and the second optical system reflects the first light and the second light to an optical path overlapping with the third light reflected by the first optical system.

[0221] In the configuration of Supplementary Note 3, the optical paths of the first and second lights overlap with the optical path of the third light reflected by the first optical system due to the second optical system disposed separately from the first optical system, so that the illumination distribution of each color light can be easily controlled.

[0222] (Supplementary Note 4) The light source device according to Supplementary Note 3, wherein the second optical system is arranged on the opposite side of the light conversion element with respect to the first optical system.

[0223] According to the structure of Supplementary Note 4, the second optical system can be formed by simple optical elements.

[0224] (Note 5) A light source device according to any one of Notes 2 to 4, wherein the light source device comprises a focusing optical system, the focusing optical system being arranged on an optical path between the light guiding optical system and the light conversion element, the focusing optical system causing the first light and the second light that have passed through the light guiding optical system to be incident on the light conversion element, causing the light emitted from the light conversion element to be incident on the light guiding optical system, and causing the first light and the second light that have passed through the light guiding optical system to be incident on a position separated from the optical axis of the focusing optical system.

[0225] According to the structure of Supplementary Note 5, the first light and the second light are incident on a position separated from the optical axis of the light-converging optical system, so that the optical path of the first light and the second light when passing through the light-guiding optical system before being incident on the light-converging optical system can be staggered from the optical path of the first light and the second light when passing through the light-guiding optical system after being emitted from the light-converging optical system. Thus, the loss of the first light and the second light can be suppressed.

[0226] (Note 6) A light source device according to Note 3, wherein the first optical system has a first optical element, the first optical element includes a first region, a second region, a third region, a fourth region and a fifth region for reflecting the third light, the fourth region is located between the first region and the second region and at the center of the first optical element, the fifth region is located between the second region and the third region, the first light and the second light emitted from the light conversion element pass through the fifth region between the second region and the third region, and the first light and the second light emitted from the second optical system pass through the fourth region.

[0227] In the configuration of Supplementary Note 6, the centers of the third light reflected by the first optical element and the second light reflected by the second optical system can be made substantially coincident.

[0228] (Note 7) A light source device according to Note 6, wherein the third wavelength band includes the second wavelength band, and a wavelength selective transmission film is arranged in the fourth area and the fifth area, and the wavelength selective transmission film transmits a portion of light having a wavelength band including the second wavelength band among the light incident on the first optical system, and reflects the other light.

[0229] In the configuration of Supplementary Note 7, since the wavelength selective transmission film is arranged in the fourth region and the fifth region, the loss of the color light in the wavelength band transmitted through the first optical system can be suppressed.

[0230] (Supplementary Note 8) A light source device according to any one of Supplementary Notes 2 to 7, wherein the light conversion element includes a reflecting portion that reflects the first light, the substrate is a metal circular plate, and the reflecting portion and the first light conversion layer are arranged in a circumferential direction of the circular plate.

[0231] In the structure of Supplementary Note 8, the light amount of the first light extracted from the light conversion element can be easily controlled.

[0232] (Note 9) A light source device according to any one of Notes 2 to 7, wherein the light conversion element further has a second light conversion layer, which converts the first light into a fourth light in a fourth band, wherein the fourth band is different from the first band and the second band and is included in the third band, and the second light conversion layer is arranged in a region different from the first light conversion layer and the reflecting portion in the circumferential direction of the substrate.

[0233] In the configuration of Supplementary Note 9, it is possible to achieve an expansion of the color gamut of color light emitted from the light source device while suppressing an increase in the size of the light source device.

[0234] (Note 10) The light source device according to Note 9, wherein the light source device further comprises a third light source, the third light source emits a fifth light of a fifth band included in the fourth band, and the optical path changing element makes the optical paths of the fifth light, the first light and the second light consistent.

[0235] In the configuration of Supplementary Note 10, even when the first light source, the second light source, and the third light source that emit light of any one of three colors are used, it is possible to suppress an increase in the size of the light source device.

[0236] (Supplementary Note 11) The light source device according to Supplementary Note 10, wherein the light conversion element includes a second wavelength selective reflection layer that is arranged on a light incident surface of the second light conversion layer and reflects the fifth light.

[0237] In the structure of Supplementary Note 11, by causing the fifth light to be regularly reflected on the second wavelength selective reflection layer, i.e., on the light incident side, the incident optical path of the fifth light to the light conversion element and the outgoing optical path from the light conversion element can be made different from each other. Therefore, it is possible to avoid a state in which the fifth light reflected from the light conversion element returns to each light source side from the light guide optical system.

[0238] (Note 12) A light source device according to any one of Notes 2 to 11, wherein the light source device also has a third optical system that reflects light including the first light, the second light and the third light emitted from the light guiding optical system toward the side of the light conversion element.

[0239] In the configuration of Supplementary Note 12, since the color light including the second light and the third light is guided to the light conversion element side by the third optical system, the optical path is bent toward the light conversion element side in the third optical system, and the size of the light source device can be suppressed.

[0240] (Note 13) A light source device according to Note 12, wherein the light conversion element has a color filter layer, which is arranged at a position different from the first light conversion layer in the radial direction of the substrate, and the color filter layer only transmits light of a specified wavelength band among the light including the first light, the second light and the third light emitted from the third optical system.

[0241] In the structure of Supplementary Note 13, the integrated light conversion element performs the light conversion function and the color filtering function, so the number of components can be reduced and the size of the light source device can be suppressed.

[0242] (Note 14) A light source device according to Note 12, wherein the light conversion element has a diffusion layer, which is arranged at a position different from the first light conversion layer in the radial direction of the substrate, and the diffusion layer transmits and diffuses the light emitted from the third optical system including the first light, the second light and the third light.

[0243] In the structure of Supplementary Note 14, the integrated light conversion element performs the light conversion function and the light diffusion function, so the number of components can be reduced and the size of the light source device can be suppressed.

[0244] (Note 15) A light source device according to any one of Notes 1 to 14, wherein the light source device further comprises a homogenizing optical system, which is arranged between the optical path changing element and the light guiding optical system to make the illumination distribution of the first light and the second light uniform.

[0245] In the configuration of Supplementary Note 15, the light source image of the colored light can be easily adjusted to suppress color unevenness.

[0246] (Supplementary Note 16) The light source device according to any one of Supplementary Notes 13 to 15, further comprising a rod lens that makes uniform the light intensity distribution of the light transmitted through the light conversion element within a plane intersecting the optical axis.

[0247] In the configuration of Supplementary Note 16, the illuminance distribution of the color light incident on the rod lens can be made uniform.

[0248] (Supplementary Note 17) The light source device according to Supplementary Note 6, wherein through holes are arranged in the fourth region and the fifth region.

[0249] In the configuration of Supplementary Note 17, the first optical system can be simply configured, and enlargement of the light source device can be suppressed.

[0250] (Note 18) A light source device according to Note 3, wherein the first optical system comprises a first reflecting element, a second reflecting element and a third reflecting element, which reflect the third light, and the first light and the second light emitted from the light conversion element pass between the second reflecting element and the third reflecting element, and the first light and the second light emitted from the second optical system pass between the first reflecting element and the second reflecting element.

[0251] In the configuration of Supplementary Note 18, the light guide optical system can be simply configured, and the optical paths of the first light and the second light can be easily aligned with the optical path of the third light.

[0252] (Supplementary Note 19) The light source device according to any one of Supplementary Notes 1 to 18, wherein the first light is blue light and the second light is red light.

[0253] In the configuration of Supplementary Note 19, it is possible to suppress an increase in the size of a light source device including a first light source that emits blue light and a second light source that emits red light.

[0254] (Note 20) A projector comprising: a light source device according to any one of Notes 1 to 19; a light modulation device that modulates light emitted from the light source device according to image information; and a projection optical system that projects the light emitted from the light modulation device.

[0255] In the structure of Supplementary Note 20, it is possible to suppress the enlargement of the light source device and realize the miniaturization of the projector.

Claims

1. A light source device, comprising: a first light source emitting a first light in a first wavelength band; a second light source that emits a second light in a second wavelength band different from the first wavelength band; a light conversion element that converts the incident first light into a third light in a third wavelength band different from the first wavelength band; an optical path changing element that makes the optical path of the first light emitted from the first light source and incident from a first direction coincide with the optical path of the second light emitted from the second light source and incident from a second direction intersecting the first direction; as well as a light guiding optical system that guides the first light and the second light emitted from the optical path changing element to the light conversion element, The light guiding optical system reflects the first light, the second light, and the third light emitted from the light conversion element.

2. The light source device according to claim 1, wherein: The light conversion element has: a substrate having a reflective layer; a first light conversion layer disposed on the reflective layer and converting the incident first light into the third light; and The first wavelength selective reflection layer is disposed on the light incident surface of the first light conversion layer and reflects the second light.

3. The light source device according to claim 2, wherein: The light guiding optical system comprises a first optical system and a second optical system. The first optical system reflects the third light emitted from the light conversion element. The second optical system reflects the first light and the second light toward an optical path overlapping with the third light reflected by the first optical system.

4. The light source device according to claim 3, wherein: The second optical system is arranged on the opposite side of the first optical system from the light conversion element.

5. The light source device according to any one of claims 2 to 4, wherein: The light source device includes a light-collecting optical system disposed on an optical path between the light-guiding optical system and the light conversion element. The condensing optical system allows the first light and the second light that have passed through the light guiding optical system to be incident on the light conversion element, and allows the light emitted from the light conversion element to be incident on the light guiding optical system. The first light and the second light having passed through the light guiding optical system are incident on a position separated from the optical axis of the light collecting optical system.

6. The light source device according to claim 3, wherein: The first optical system includes a first optical element, wherein the first optical element includes a first region, a second region, a third region, a fourth region, and a fifth region for reflecting the third light. The fourth region is located between the first region and the second region and is located at the center of the first optical element. The fifth area is located between the second area and the third area, The first light and the second light emitted from the light conversion element pass through the fifth region. The first light and the second light emitted from the second optical system pass through the fourth region.

7. The light source device according to claim 6, wherein: The third band includes the second band, A wavelength selective transmission film is disposed in the fourth region and the fifth region. The wavelength selective transmission film transmits a portion of light having a wavelength band including the second wavelength band among the light incident on the first optical system and reflects the other light.

8. The light source device according to any one of claims 2 to 4 and claim 6, wherein: The light conversion element includes a reflecting portion that reflects the first light. The substrate is a metal circular plate. The reflecting portion and the first light conversion layer are arranged in different regions in the circumferential direction of the substrate.

9. The light source device according to claim 8, wherein: The light conversion element further includes a second light conversion layer that converts the first light into fourth light in a fourth wavelength band, wherein the fourth wavelength band is different from the first wavelength band and the second wavelength band and is included in the third wavelength band. The second light conversion layer is disposed in a region different from the first light conversion layer and the reflection portion in the circumferential direction of the substrate.

10. The light source device according to claim 9, wherein: The light source device further includes a third light source that emits fifth light in a fifth wavelength band included in the fourth wavelength band. The optical path changing element makes the optical paths of the fifth light, the first light, and the second light consistent with each other.

11. The light source device according to claim 10, wherein: The light conversion element includes a second wavelength selective reflection layer, the second wavelength selective reflection layer being arranged on the light incident surface of the second light conversion layer and reflecting the fifth light.

12. The light source device according to any one of claims 2 to 4, wherein: The light source device further includes a third optical system configured to reflect light including the first light, the second light, and the third light emitted from the light guide optical system toward the light conversion element.

13. The light source device according to claim 12, wherein: The light conversion element includes a color filter layer, and the color filter layer is provided at a position different from the first light conversion layer in the radial direction of the substrate. The color filter layer transmits only light of a predetermined wavelength band among the light including the first light, the second light, and the third light emitted from the third optical system.

14. The light source device according to claim 12, wherein: The light conversion element includes a diffusion layer provided at a position different from that of the first light conversion layer in the radial direction of the substrate. The diffusion layer transmits and diffuses light including the first light, the second light, and the third light emitted from the third optical system.

15. The light source device according to any one of claims 1 to 4, wherein: The light source device further includes a uniformizing optical system disposed between the optical path changing element and the light guiding optical system and uniformizing the illumination distribution of the first light and the second light.

16. The light source device according to claim 13 or 14, wherein: The light source device further includes a rod lens that makes light intensity distribution of the light transmitted through the light conversion element uniform within a plane intersecting the optical axis.

17. The light source device according to claim 6, wherein: Through holes are arranged in the fourth region and the fifth region.

18. The light source device according to claim 3, wherein: The first optical system comprises a first reflecting element, a second reflecting element and a third reflecting element, which reflect the third light. The first light and the second light emitted from the light conversion element pass between the second reflecting element and the third reflecting element. The first light and the second light emitted from the second optical system pass between the first reflecting element and the second reflecting element.

19. The light source device according to any one of claims 1 to 4, wherein: The first light is blue light, The second light is red light.

20. A projector comprising: The light source device according to any one of claims 1 to 4; a light modulation device for modulating light emitted from the light source device according to image information; and A projection optical system projects the light emitted from the light modulation device.

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