Light source device and projector

Abstract

A light source device and a projector with excellent light utilization efficiency are provided. [Solution] The light source device of the present invention includes a first light source that emits first light, a wavelength conversion element that converts the first light into second light, a first optical member that transmits the first light and reflects the second light, a first light guide section that guides the second light, a first reflecting member that reflects the first light and the second light, and a support member that supports the wavelength conversion element. The wavelength conversion element has a first surface onto which the first light is incident, second and third surfaces that intersect with the first surface and face in opposite directions, and fourth and fifth surfaces that intersect with the first, second, and third surfaces and face in opposite directions. The first reflecting member is disposed on the second surface side of the wavelength conversion element and the first light guide section, the second light is emitted from the third surface side of the first light guide section, and the support member has a first support section that supports the fourth surface and a second support section that supports the fifth surface. The first optical member covers the first light guiding section disposed between the first support section and the second support section on the opposite side to the wavelength conversion element.

Description

[Technical Field]

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

[0002] A light source device for use in a projector has been proposed that utilizes fluorescence emitted from a phosphor when the phosphor is irradiated with excitation light emitted from a light-emitting element. Patent Document 1 listed below discloses a light source device that includes a flat wavelength conversion member containing a phosphor and a light-emitting diode that emits excitation light. In this light source device, excitation light is incident on a larger incident surface of the wavelength conversion member than the other surfaces, and fluorescence is emitted from a smaller exit surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2006 / 054203 Summary of the Invention [Problem to be solved by the invention]

[0004] In the light source device of Patent Document 1, the fluorescence generated inside the wavelength conversion member is totally reflected at the interface between the surface of the wavelength conversion member and the air layer, propagates inside the wavelength conversion member, and is emitted from the emission surface. However, components of the fluorescence that are incident on the interface between the wavelength conversion member and the air layer at an angle less than the critical angle are not totally reflected at the interface and therefore leak from the interface to the outside before reaching the emission surface. This poses a problem of reduced fluorescence utilization efficiency. [Means for solving the problem]

[0005] In order to solve the above problems, a light source device according to one aspect of the present invention provides:

[0006] A projector according to one aspect of the present invention comprises a light source device according to one aspect of the present invention, an optical modulation device that modulates light emitted from the light source device, and a projection optical device that projects the light modulated by the optical modulation device. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic configuration diagram of a projector according to a first embodiment. [Figure 2] FIG. 2 is a side cross-sectional view showing a schematic configuration of the light source device. [Figure 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2. [Figure 4] FIG. 2 is a plan view of the light source device viewed from the +X side to the −X side. [Figure 5] FIG. 10 is a cross-sectional view of the configuration of a light source device according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] (First embodiment) A first embodiment of the present invention will be described below with reference to the drawings. The projector of this embodiment is an example of a projector that uses a liquid crystal panel as a light modulation device. In the drawings below, the dimensions of some components may be shown on different scales to make them easier to see.

[0009] FIG. 1 is a schematic configuration diagram of a projector 1 according to this embodiment. 1, the projector 1 of this embodiment is a projection-type image display device that displays a color image on a screen SCR, which is a projection surface. The projector 1 is equipped with three light modulation devices corresponding to red light LR, green light LG, and blue light LB.

[0010] The projector 1 includes a first illumination device 11, a second illumination device 12, a color separation optical system 3, a light modulation device 4R, a light modulation device 4G, a light modulation device 4B, a light combining element 5, and a projection optical device 6.

[0011] The first illumination device 11 emits yellow illumination light WL toward the color separation optical system 3. The second illumination device 12 emits blue light LB toward the light modulation device 4B. Detailed configurations of the first illumination device 11 and the second illumination device 12 will be described later.

[0012] In the following, in the drawings, an XYZ Cartesian coordinate system will be used as necessary for explanation. The Z axis is an axis along the up-down direction of the projector 1. The X axis is an axis parallel to the optical axis AX1 of the first illumination device 11 and the optical axis AX2 of the second illumination device 12. The Y axis is an axis perpendicular to the X and Z axes. The optical axis AX1 of the first illumination device 11 is the central axis of the fluorescent light Y emitted from the first illumination device 11. The optical axis AX2 of the second illumination device 12 is the central axis of the blue light LB emitted from the second illumination device 12. One of the two directions along the X axis will be referred to as the +X direction, and the opposite direction will be referred to as the -X direction. One of the two directions along the Y axis will be referred to as the +Y direction, and the opposite direction will be referred to as the -Y direction. One of the two directions along the Z axis will be referred to as the +Z direction, and the opposite direction will be referred to as the -Z direction. Furthermore, when the two directions along the X axis are referred to collectively without distinction, they are referred to as the X-axis direction; when the two directions along the Y axis are referred to collectively without distinction, they are referred to as the Y-axis direction; and when the two directions along the Z axis are referred to collectively without distinction, they are referred to as the Z-axis direction.

[0013] The color separation optical system 3 separates the yellow illumination light WL emitted from the first illumination device 11 into red light LR and green light LG. The color separation optical system 3 includes a dichroic mirror 7, a first reflecting mirror 8a, and a second reflecting mirror 8b.

[0014] The dichroic mirror 7 separates the illumination light WL into red light LR and green light LG. The dichroic mirror 7 transmits the red light LR and reflects the green light LG. The second reflecting mirror 8b is disposed in the optical path of the green light LG. The second reflecting mirror 8b reflects the green light LG reflected by the dichroic mirror 7 toward the optical modulation device 4G. The first reflecting mirror 8a is disposed in the optical path of the red light LR. The first reflecting mirror 8a reflects the red light LR transmitted through the dichroic mirror 7 toward the optical modulation device 4R.

[0015] On the other hand, the blue light LB emitted from the second illumination device 12 is reflected by the reflecting mirror 9 toward the light modulation device 4B.

[0016] The configuration of the second illumination device 12 will be described below. The second illumination device 12 includes a light source unit 44, a condenser lens 45, a diffuser plate 46, a rod lens 47, and a relay lens 48. The light source unit 44 is configured with at least one semiconductor laser. The light source unit 44 emits blue light LB made of laser light. Note that the light source unit 44 is not limited to a semiconductor laser, and may be configured with an LED that emits blue light.

[0017] The condenser lens 45 is composed of a convex lens. The condenser lens 45 causes the blue light LB emitted from the light source unit 44 to enter the diffuser plate 46 in a substantially condensed state. The diffuser plate 46 diffuses the blue light LB emitted from the condenser lens 45 with a predetermined degree of diffusion, generating blue light LB having a substantially uniform luminous intensity distribution similar to that of the illumination light WL emitted from the first lighting device 11. The diffuser plate 46 may be, for example, frosted glass made of optical glass.

[0018] The blue light LB diffused by the diffuser plate 46 is incident on the rod lens 47. The rod lens 47 has a rectangular columnar shape extending along the optical axis AX2 of the second illumination device 12. The rod lens 47 has a light incident end surface 47a at one end and a light exit end surface 47b at the other end. The diffuser plate 46 is fixed to the light incident end surface 47a of the rod lens 47 via an optical adhesive (not shown). It is desirable that the refractive index of the diffuser plate 46 and the refractive index of the rod lens 47 match as closely as possible.

[0019] The blue light LB is propagated through the rod lens 47 while being totally reflected inside the rod lens 47, and is emitted from the light emitting end surface 47b with the uniformity of the illuminance distribution increased. The blue light LB emitted from the rod lens 47 is incident on the relay lens 48. The relay lens 48 causes the blue light LB, whose uniformity of the illuminance distribution has been increased by the rod lens 47, to be incident on the reflecting mirror 9.

[0020] The shape of the light exit end surface 47b of the rod lens 47 is a rectangle that is approximately similar to the shape of the image forming area of ​​the light modulation device 4B, so that the blue light LB exiting from the rod lens 47 is efficiently incident on the image forming area of ​​the light modulation device 4B.

[0021] The light modulation device 4R modulates the red light LR according to image information to form image light corresponding to the red light LR. The light modulation device 4G modulates the green light LG according to image information to form image light corresponding to the green light LG. The light modulation device 4B modulates the blue light LB according to image information to form image light corresponding to the blue light LB.

[0022] Each of the light modulation devices 4R, 4G, and 4B uses, for example, a transmissive liquid crystal panel. Polarizing plates (not shown) are disposed on the entrance and exit sides of the liquid crystal panels. The polarizing plates allow only linearly polarized light in a specific direction to pass through.

[0023] A field lens 10R is disposed on the incident side of the optical modulation device 4R. A field lens 10G is disposed on the incident side of the optical modulation device 4G. A field lens 10B is disposed on the incident side of the optical modulation device 4B. The field lens 10R collimates the chief ray of the red light LR incident on the optical modulation device 4R. The field lens 10G collimates the chief ray of the green light LG incident on the optical modulation device 4G. The field lens 10B collimates the chief ray of the blue light LB incident on the optical modulation device 4B.

[0024] The light combining element 5 receives the image lights emitted from the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B, combines the image lights corresponding to the red light LR, the green light LG, and the blue light LB, and emits the combined image light toward the projection optical device 6. The light combining element 5 may be, for example, a cross dichroic prism.

[0025] The projection optical device 6 is composed of a plurality of projection lenses. The projection optical device 6 enlarges and projects the image light combined by the light combining element 5 onto the screen SCR, thereby displaying a color image on the screen SCR.

[0026] Next, the configuration of the first illumination device 11 will be described. The first illumination device 11 includes a light source device 30A, an integrator optical system 90, a polarization conversion element 93, and a superimposing optical system 94. Fig. 2 is a side cross-sectional view showing a schematic configuration of a light source device 30A of this embodiment, Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2.

[0027] As shown in FIG. 2, the light source device 30A of this embodiment includes a housing 31, a first light source 41, a second light source 42, a wavelength conversion element 51, a first optical member 55, a second optical member 56, a first light guiding section 71, a second light guiding section 72, a support member 80, a pressing member 88, a first reflecting member 81, a second reflecting member 82, and a third reflecting member 83.

[0028] The housing 31 constitutes the exterior of the light source device 30A. The housing 31 accommodates the first light source 41, the second light source 42, the wavelength conversion element 51, the first optical member 55, the first reflecting member 81, the second reflecting member 82, the third reflecting member 83, the second optical member 56, the first light guiding section 71, the second light guiding section 72, and the support member 80. The housing 31 is composed of a bottom plate section 32 and a lid body 33.

[0029] The housing 31 has an outlet 31K for extracting the yellow fluorescence Y emitted from the wavelength conversion element 51, the first light guiding section 71, and the second light guiding section 72 to the outside as illumination light WL. The outlet 31K is an opening defined by an opening 33K provided in a second side wall section 33d of the lid 33 (described later) and a part of the frame section 32b of the bottom plate section 32. The configuration of the outlet 31K is not particularly limited, and a configuration may be adopted in which the outlet 31K is closed by a lid made of a light-transmitting member to hermetically seal the inside of the housing 31.

[0030] The housing 31 is configured by arranging the sidewalls of the bottom plate 32 and the lid 33 so that they butt against each other. The lid 33 and the bottom plate 32 are fixed to each other via fixing members such as adhesive or screws (not shown). In this manner, in the light source device 30A, the components of the first light source 41, the second light source 42, the wavelength conversion element 51, the first optical member 55, the first reflecting member 81, the second reflecting member 82, the third reflecting member 83, the second optical member 56, the first light guiding section 71, the second light guiding section 72, and the support member 80 are housed in a space surrounded by the housing 31. This makes it possible to prevent foreign matter such as dust from adhering to the components.

[0031] The bottom plate 32 has a generally plate-like shape. The lid 33 has a box shape with one side open, and has a top wall 33a, a first side wall 33c, a second side wall 33d, a third side wall 33e, a fourth side wall 33f, and an opening 33K.

[0032] The bottom plate portion 32 is disposed along the XZ plane and has a recess that houses the second light source 42. The bottom plate portion 32 has a base portion 32a and a frame portion 32b. The base portion 32a is a plate-shaped member that forms the main body of the bottom plate portion 32 and extends long in the X-axis direction. The frame portion 32b is configured integrally with the base portion 32a and is provided on a surface located on the +Y side of the base portion 32a.

[0033] The bottom plate portion 32 is connected to the second light source 42 so as to be able to transfer heat. For this reason, it is desirable that the bottom plate portion 32 be made of a material that has a predetermined strength and high thermal conductivity. Therefore, it is desirable that the material of the bottom plate portion 32 be a metal such as aluminum or stainless steel, and in particular, an aluminum alloy such as a 6061 series aluminum alloy.

[0034] In the cover 33, the top wall 33a is disposed along the XZ plane and has a recess that accommodates the first light source 41. The first side wall 33c and the second side wall 33d intersect with the X axis along the longitudinal direction of the light source device 30A and are positioned on opposite sides of each other in the X axis direction. The first side wall 33c is positioned on the -X side, which is one side in the X axis direction. The second side wall 33d is positioned on the +X side, which is the other side in the X axis direction. The third side wall 33e and the fourth side wall 33f are positioned on opposite sides of each other in the Z axis direction, which intersects with the longitudinal direction of the light source device 30A. In this embodiment, the third side wall 33e is positioned on the +Z side, which is one side in the Z axis direction. The fourth side wall 33f is positioned on the -Z side, which is the other side in the Z axis direction.

[0035] The top wall portion 33a is connected to the first light source 41 in a manner that allows heat transfer. For this reason, it is desirable that the lid body 33 be made of a material that has a predetermined strength and high thermal conductivity, similar to the bottom plate portion 32. For this reason, it is desirable that the material of the lid body 33 be a metal such as aluminum or stainless steel, similar to the bottom plate portion, and in particular, an aluminum alloy such as 6061 series aluminum alloy.

[0036] The first light source 41 has a plurality of first light-emitting elements 411. The plurality of first light-emitting elements 411 are respectively mounted on the top wall portion 33a of the housing 31. Note that the number of first light-emitting elements 411 included in the first light source 41 is not particularly limited. The first light-emitting element 411 emits an excitation light beam E1 in a first wavelength band. The first light-emitting element 411 is configured by, for example, a light-emitting diode (LED). The first light-emitting element 411 is disposed opposite the wavelength conversion element 51 and emits the excitation light beam E1 toward the wavelength conversion element 51. The first wavelength band is, for example, a wavelength band from purple to blue of 400 nm to 480 nm, and the peak wavelength is, for example, 445 nm. The multiple first light-emitting elements 411 are disposed along the X-axis direction, which is the longitudinal direction of the wavelength conversion element 51. In this way, the first light source 41 emits excitation light E consisting of multiple blue excitation light beams E1 toward the wavelength conversion element 51.

[0037] The second light source 42 is disposed on the opposite side of the wavelength conversion element 51 from the first light source 41. The second light source 42 has a plurality of second light-emitting elements 421. The plurality of second light-emitting elements 421 are respectively mounted in recesses in the bottom plate portion 32 of the housing 31. The number of second light-emitting elements 421 included in the second light source 42 is not particularly limited. The second light-emitting elements 421 are configured with the same light-emitting elements as the first light-emitting elements 411. Therefore, the second light source 42 emits excitation light E consisting of a plurality of blue excitation light rays E1 toward the wavelength conversion element 51. The excitation light E in this embodiment corresponds to an example of the "first light" in the present invention.

[0038] The wavelength conversion element 51 has a columnar shape extending along the X-axis and has six faces. The sides of the wavelength conversion element 51 extending along the X-axis are longer than the sides extending along the Y-axis and the Z-axis. The X-axis direction corresponds to the longitudinal direction of the wavelength conversion element 51. The Y-axis direction is a direction parallel to the shortest side of the wavelength conversion element 51. The length of the sides along the Y-axis is shorter than the length of the sides along the Z-axis. That is, the cross-sectional shape of the wavelength conversion element 51 cut along a plane along the YZ plane is rectangular, as shown in FIG. 3.

[0039] The wavelength conversion element 51 has a front surface 51a, a back surface 51b, a first end surface 51c, a second end surface 51d, a first side surface 51e, and a second side surface 51f. The front surface 51a and the back surface 51b intersect with the Y axis and face opposite sides along the Y axis. In this embodiment, the front surface 51a is located on the +Y side, which is one side along the Y axis. The back surface 51b is located on the -Y side, which is the other side along the Y axis. Excitation light E is incident on the front surface 51a from the first light source 41 arranged on the top wall 33a via the first optical member 55 and the first light guiding unit 71. The front surface 51a in this embodiment corresponds to an example of the "first surface of the wavelength conversion element" in the present invention.

[0040] As shown in FIG. 2, the first end face 51c and the second end face 51d intersect the front face 51a and the back face 51b and face opposite each other in the X-axis direction along the longitudinal direction of the wavelength conversion element 51. In this embodiment, the first end face 51c is located on the −X side, which is one side in the X-axis direction. The second end face 51d is located on the +X side, which is the other side in the X-axis direction. The first end face 51c of this embodiment corresponds to an example of the “second surface of the wavelength conversion element” of the present invention, and the second end face 51d of this embodiment corresponds to an example of the “third surface of the wavelength conversion element” of the present invention.

[0041] 3, the first side surface 51e and the second side surface 51f intersect the front surface 51a and the back surface 51b and the first end surface 51c and the second end surface 51d, and face opposite each other in the Z-axis direction. In this embodiment, the first side surface 51e is located on the +Z side, which is one side in the Z-axis direction, and the second side surface 51f is located on the -Z side, which is the other side in the Z-axis direction. The first side surface 51e of this embodiment corresponds to an example of the "fourth surface of the wavelength conversion element" of the present invention, and the second side surface 51f of this embodiment corresponds to an example of the "fifth surface of the wavelength conversion element" of the present invention.

[0042] The wavelength conversion element 51 contains at least a yellow phosphor and converts the excitation light E in a first wavelength band emitted from the first light source 41 and the second light source 42 into yellow fluorescence Y in a second wavelength band different from the first wavelength band. As will be described in detail later, part of the yellow fluorescence Y generated inside the wavelength conversion element 51 is emitted from the front surface 51a to the first light guiding section 71, and another part of the fluorescence Y is emitted from the back surface 51b to the second light guiding section 72.

[0043] The wavelength conversion element 51 includes a ceramic phosphor made of a polycrystalline phosphor that converts the wavelength of the excitation light E into yellow fluorescence Y. The wavelength conversion element 51 of this embodiment is made of a phosphor that does not have light-scattering properties, that is, a so-called transparent phosphor. The second wavelength band of the yellow fluorescence Y is, for example, a yellow wavelength band of 490 to 750 nm. The center wavelength of the second wavelength band is, for example, 550 nm. In other words, the fluorescence Y is yellow fluorescence containing a red light component and a green light component. The yellow fluorescence Y of this embodiment corresponds to an example of the "second light" of the present invention.

[0044] In this specification, the transparent phosphor refers to a phosphor having a total light transmittance of 80% or more for fluorescent light. The transparent phosphor constituting the wavelength conversion element 51 may be a transparent single crystal or polycrystalline body having a total light transmittance of 80% or more, such as a YAG ceramic phosphor obtained by sintering a plurality of YAG phosphor particles. The wavelength conversion element 51 made of such a material converts the excitation light E into yellow fluorescent light Y.

[0045] The wavelength conversion element 51 may contain a single crystal phosphor instead of a polycrystalline phosphor. Alternatively, the wavelength conversion element 51 may be made of fluorescent glass. Alternatively, the wavelength conversion element 51 may be made of a material in which a large number of phosphor particles are dispersed in a binder made of glass or resin. A wavelength conversion element 51 made of such a material converts the excitation light E into yellow fluorescence Y.

[0046] Specifically, the material of the wavelength conversion element 51 includes, for example, an yttrium-aluminum-garnet (YAG) phosphor. Taking YAG:Ce containing cerium (Ce) as an activator as an example, the material of the wavelength conversion element 51 may be a material obtained by mixing raw material powders containing constituent elements such as Y2O3, Al2O3, and CeO3 and causing a solid-phase reaction, Y-Al-O amorphous particles obtained by a wet method such as a coprecipitation method or a sol-gel method, or YAG particles obtained by a gas-phase method such as a spray-drying method, a flame pyrolysis method, or a thermal plasma method.

[0047] 2, the first reflecting member 81 is disposed on the −X side of the first light source 41, the second light source 42, the wavelength conversion element 51, the first optical member 55, the second optical member 56, the first light guiding section 71, and the second light guiding section 72. The first reflecting member 81 is disposed on the first side wall portion 33c of the lid body 33 and part of the frame portion 32b of the bottom plate portion 32. Note that the first reflecting member 81 does not necessarily have to be provided over the entire region described above, but only needs to be provided in at least the region on the first end surface 51c side of the wavelength conversion element 51, the first optical member 55, the second optical member 56, the first light guiding section 71, and the second light guiding section 72.

[0048] The first reflecting member 81 reflects the fluorescence Y that has propagated through the wavelength conversion element 51, the first light guiding section 71, and the second light guiding section 72 and reached the first reflecting member 81. The first reflecting member 81 also reflects the excitation light E that has propagated through the first light guiding section 71 and the second light guiding section 72 and reached the first reflecting member 81. That is, the first reflecting member 81 reflects the fluorescence Y and the excitation light E. The first reflecting member 81 is made of, for example, a metal film, a dielectric multilayer film, a scattering member containing barium sulfate, or the like.

[0049] 3, the wavelength conversion element 51 is supported in the Z-axis direction by a support member 80. The support member 80 has a first support portion 801 and a second support portion 802.

[0050] The first support member 801 is disposed on a third side wall portion 33e of the lid body 33, and supports a first side surface 51e (described later) of the wavelength conversion element 51. The second reflecting member 82 is provided on a surface of the first support member 801 facing the wavelength conversion element 51. More specifically, the second reflecting member 82 is provided on a side surface 801c of the first support member 801 that faces the first side surface 51e of the wavelength conversion element 51 and the region of the first light guiding section 71 on the first side surface 51e side. The third side wall portion 33e of the lid body 33 is connected to the wavelength conversion element 51 via the support member 80 and the second reflecting member 82 in a heat-transferable manner.

[0051] The second reflecting member 82 reflects the fluorescence Y and the excitation light E. The second reflecting member 82 is made of, for example, a metal film, a dielectric multilayer film, a scattering member, or the like. Therefore, the second reflecting member 82 reflects, for example, the excitation light E that has passed through the wavelength conversion element 51, the first light guiding section 71, and the second light guiding section 72 and reached the second reflecting member 82, and causes the reflected light to enter the wavelength conversion element 51. This can improve the efficiency of conversion from the excitation light E to fluorescence Y. Furthermore, the second reflecting member 82 reflects the fluorescence Y that has been emitted from the wavelength conversion element 51, propagated through the first light guiding section 71 and the second light guiding section 72, and reached the second reflecting member 82. This can improve the extraction efficiency of the fluorescence Y.

[0052] The second support portion 802 is disposed on a fourth side wall portion 33f of the lid 33, and supports a second side surface 51f (described later) of the wavelength conversion element 51. The third reflecting member 83 is provided on a surface of the second support portion 802 facing the wavelength conversion element 51. More specifically, the third reflecting member 83 is provided on a side surface 802c of the second support portion 802 that faces the second side surface 51f of the wavelength conversion element 51 and the region of the second light guiding portion 72 on the second side surface 51f side. The fourth side wall portion 33f of the lid 33 is connected to the wavelength conversion element 51 via the support member 80 and the third reflecting member 83 in a heat-transferable manner.

[0053] Furthermore, the third reflecting member 83 reflects the fluorescence Y and the excitation light E. The third reflecting member 83 is made of, for example, a metal film, a dielectric multilayer film, a scattering member, or the like. Therefore, the third reflecting member 83 reflects, for example, the excitation light E that has passed through the wavelength conversion element 51, the first light guiding section 71, and the second light guiding section 72 and reached the third reflecting member 83, and causes the reflected light to enter the wavelength conversion element 51. This can improve the efficiency of conversion from the excitation light E to the fluorescence Y. Furthermore, the third reflecting member 83 reflects the fluorescence Y that has been emitted from the wavelength conversion element 51, propagated through the first light guiding section 71 and the second light guiding section 72, and reached the third reflecting member 83. This can improve the extraction efficiency of the fluorescence Y.

[0054] In this way, according to the light source device 30 of this embodiment, the heat of the wavelength conversion element 51 can be efficiently released to the outside through the lid body 33, thereby suppressing the temperature rise of the wavelength conversion element 51 and preventing the decrease in wavelength conversion efficiency that accompanies the temperature rise of the wavelength conversion element 51.

[0055] The first light guiding unit 71 is supported in the Z-axis direction by the first support unit 801 and the second support unit 802 via the second reflecting member 82 and the third reflecting member 83. The first light guiding unit 71 is also disposed between the wavelength conversion element 51 and the first optical member 55 in the Y-axis direction, and guides the fluorescence Y converted by the wavelength conversion element 51.

[0056] The first light guiding section 71 of the present embodiment includes a first light-transmissive member 711 and an air layer 712. The first light-transmissive member 711 is fixed to the surface 51a of the wavelength conversion element 51 with a light-transmissive adhesive 713, and transmits the excitation light E and the yellow fluorescence Y. The air layer 712 is provided between the first light-transmissive member 711 and the first optical member 55.

[0057] According to the first light guiding section 71 of the present embodiment, the first light-transmissive member 711 and the wavelength conversion element 51 are joined together, and therefore no air layer exists between the first light-transmissive member 711 and the wavelength conversion element 51. Therefore, the fluorescence Y emitted from the wavelength conversion element 51 is less likely to be totally reflected at the interface with the first light-transmissive member 711, and is therefore efficiently incident into the first light-transmissive member 711. Therefore, the first light guiding section 71 can efficiently take in the fluorescence Y.

[0058] In this embodiment, the refractive index of the first light-transmissive member 711 (1.4: quartz) is smaller than the refractive index of the wavelength conversion element 51 (YAG: 1.7). Materials for the first light-transmissive member 711 that satisfy this relationship include, in addition to quartz, borosilicate glass such as BK7, synthetic quartz, and quartz crystal. According to this configuration, the fluorescence Y is refracted when it enters the first light-transmissive member 711 from the wavelength conversion element 51, thereby reducing the angle it forms with the X-axis along the major axis of the first light-transmissive member 711. In other words, the fluorescence Y propagating through the first light-transmissive member 711 is incident at a small angle on the end face 711d on the second end face 51d side, which is orthogonal to the X-axis. Therefore, the first light-transmissive member 711 can efficiently extract the fluorescence Y from the end face 711d on the second end face 51d side.

[0059] Furthermore, it is desirable that the thermal conductivity of the first light-transmissive member 711 be greater than the thermal conductivity of the wavelength conversion element 51. Materials for the first light-transmissive member 711 that satisfy this relationship include, for example, SiC, GaN, MgO, YAG, sapphire, and diamond. The first light-transmissive member 711 of this embodiment is made of, for example, quartz. With this configuration, heat from the wavelength conversion element 51 is efficiently conducted to the first light-transmissive member 711 via the light-transmissive adhesive 713, thereby suppressing a temperature rise in the wavelength conversion element 51. This makes it possible to suppress a decrease in luminous efficiency due to a temperature rise in the wavelength conversion element 51.

[0060] The second light guiding unit 72 is supported in the Z-axis direction by the first support unit 801 and the second support unit 802 via the second reflecting member 82 and the third reflecting member 83. The second light guiding unit 72 is disposed between the wavelength conversion element 51 and the second optical member 56, and guides the fluorescence Y converted by the wavelength conversion element 51. The second light guiding section 72 of the present embodiment includes a second light-transmissive member 721 and an air layer 722. The second light-transmissive member 721 is disposed by being bonded to the rear surface 51b of the wavelength conversion element 51 with a light-transmissive adhesive 713, and transmits the excitation light E and the yellow fluorescence Y. The air layer 722 is provided between the second light-transmissive member 721 and the second optical member 56.

[0061] According to the second light-guiding section 72 of the present embodiment, similarly to the first light-guiding section 71, the absence of an air layer between the first light-transmissive member 711 and the wavelength conversion element 51 suppresses total reflection of the fluorescence Y at the interface, and therefore the fluorescence Y can be efficiently taken into the second light-transmissive member 721.

[0062] Like the first light-transmissive member 711, the second light-transmissive member 721 is made of a material whose refractive index is smaller than that of the wavelength conversion element 51. Therefore, the second light-transmissive member 721 can efficiently extract the fluorescence Y from the end face 721d on the second end face 51d side. Also, like the first light-transmissive member 711, the second light-transmissive member 721 is desirably made of a material whose thermal conductivity is greater than that of the wavelength conversion element 51. With this configuration, heat from the wavelength conversion element 51 is efficiently conducted to the second light-transmissive member 721, making it possible to suppress a decrease in light-emitting efficiency that accompanies a rise in temperature of the wavelength conversion element 51.

[0063] According to the light source device 30A of the present embodiment, by arranging the air layer 712 having a large refractive index difference with respect to the first light-transmissive member 711 in the first light guiding section 71, it is possible to facilitate total reflection of the fluorescence Y generated in the wavelength conversion element 51 at the interface between the first light-transmissive member 711 and the air layer 712. Similarly, by arranging the air layer 722 having a large refractive index difference with respect to the second light-transmissive member 721 in the second light guiding section 72, it is possible to facilitate total reflection of the fluorescence Y generated in the wavelength conversion element 51 at the interface between the second light-transmissive member 721 and the air layer 722. Therefore, according to the light source device 30A of the present embodiment, in the first light guiding section 71, the fluorescence Y propagating within the first light-transmissive member 711 by total reflection can be emitted from the end face 711d on the second end face 51d side of the first light-transmissive member 711, while in the second light guiding section 72, the fluorescence Y propagating within the second light-transmissive member 721 by total reflection can be emitted from the end face 721d on the second end face 51d side of the second light-transmissive member 721. This makes it possible to improve the extraction efficiency of the fluorescence Y.

[0064] The fluorescence Y that has passed through the first light-transmissive member 711 and is emitted into the air layer 712 is incident on the first optical member 55 . The first optical member 55 is disposed between the first light source 41 and the wavelength conversion element 51. As shown in Fig. 3, the first optical member 55 is disposed on an upper surface 801a on the +Y side of the first support portion 801 and an upper surface 802a on the +Y side of the second support portion 802. As a result, the first optical member 55 covers the side (+Y side) of the first light guiding portion 71 disposed between the first support portion 801 and the second support portion 802 opposite to the wavelength conversion element 51. The first optical member 55 transmits the excitation light E and reflects the fluorescence Y.

[0065] The first optical member 55 includes a first transparent substrate 551 and a first optical layer 552 . The first transparent substrate 551 is made of a light-transmitting material such as borosilicate glass such as BK7, quartz, synthetic quartz, crystal, SiC, GaN, MgO, YAG, sapphire, or diamond. The first transparent substrate 551 must be made of a material that can transmit at least the excitation light E. The first transparent substrate 551 has a plate-like shape extending along the X-axis. As shown in FIG. 3, the first transparent substrate 551 has a rectangular cross-sectional shape cut along the YZ plane, and extends elongated in the X-axis direction.

[0066] The first optical layer 552 is made of, for example, a dielectric multilayer film, and has the optical property of transmitting the excitation light E and reflecting the fluorescence Y. The first optical layer 552 is formed on the surface of the first transparent substrate 551. The first optical layer 552 is disposed between the wavelength conversion element 51 and the first transparent substrate 551. That is, the first optical layer 552 is provided on one of the two surfaces of the first transparent substrate 551, the surface 551a facing the wavelength conversion element 51. With this configuration, as will be described later, the fluorescence Y is reflected by the first optical layer 552 without entering the first transparent substrate 551, thereby suppressing loss of the fluorescence Y due to propagation inside the first transparent substrate 551 and improving the utilization efficiency of the fluorescence Y.

[0067] The first optical member 55 is pressed against the support member 80 by a pressing member 88. The pressing member 88 is disposed between the first optical member 55 and the top wall portion 33a of the cover 33 of the housing 31. The pressing member 88 is made of an elastic member that generates a pressing force that presses the first optical member 55 against the support member 80. Note that the elastic member that constitutes the pressing member 88 may be, for example, a spring member or an elastomer.

[0068] The pressing member 88 abuts against a surface 551b of the first transparent substrate 551 of the first optical member 55 on the side opposite to the first optical layer 552. With this configuration, the first optical layer 552 does not directly press against the pressing member 88, and therefore, it is possible to suppress the occurrence of defects such as deformation or breakage caused by the application of an external force to the first optical layer 552.

[0069] In this way, the first optical member 55 covers the +Y side of the first light guiding unit 71 sandwiched between the first support unit 801 and the second support unit 802 in the Z axis direction. The width of the first optical member 55 in the Z axis direction is larger than the gap generated between the first support unit 801 and the second support unit 802. In other words, the first optical member 55 is provided so as to straddle the first support unit 801 and the second support unit 802 in the Z axis direction. Therefore, both ends of the first optical member 55 are disposed on the first support unit 801 and the second support unit 802.

[0070] Here, in the first optical member 55, the first optical layer 552 is formed over the entire surface of the first transparent substrate 551, and therefore it is difficult to form the first optical layer 552 uniformly all the way to the edge of the first transparent substrate 551. Furthermore, in the manufacturing process of the first optical member 55, the edge surface of the first transparent substrate 551 on which the first optical layer 552 is formed is polished, and at this time, chipping is likely to occur on the edge surface of the first transparent substrate 551, and there is a risk that part of the first optical layer 552 will be missing along with the edge surface of the first transparent substrate 551. In this way, the edge of the first optical layer 552 is considered to be a defective portion where desired optical properties will not be obtained due to defects caused by poor film formation or chipping.

[0071] In light source device 30A of the present embodiment, because first optical member 55 straddles between first support portion 801 and second support portion 802, both ends of first optical member 55, i.e., ends of first optical layer 552 corresponding to the above-described defective portion, can be positioned outside the gap between first support portion 801 and second support portion 802. In the case of the present embodiment, an air layer 712 of first light guiding section 71 is provided in the gap on the +Y side between first support portion 801 and second support portion 802.

[0072] Furthermore, in the present embodiment, the first optical layer 552 abuts against the first support portion 801 and the second support portion 802, and therefore, as shown in Fig. 3, the defect portion 552K of the first optical layer 552 does not communicate with the air layer 712 located in the gap between the first support portion 801 and the second support portion 802. Therefore, a portion of the fluorescence Y propagating through the air layer 712 does not enter the defect portion 552K and leak toward the first light source 41, resulting in loss. Therefore, by suppressing the light loss caused by the defect portion 552K of the first optical layer 552, the light utilization efficiency of the fluorescence Y can be improved.

[0073] The fluorescence Y that has passed through the second light-transmissive member 721 and is emitted into the air layer 722 is incident on the second optical member 56 . The second optical member 56 is disposed between the second light source 42 and the wavelength conversion element 51. As shown in Fig. 3, the second optical member 56 is disposed on a lower surface 801b on the -Y side of the first support portion 801 and a lower surface 802b on the -Y side of the second support portion 802. As a result, the second optical member 56 covers the side (-Y side) of the second light guiding portion 72 disposed between the first support portion 801 and the second support portion 802 opposite to the wavelength conversion element 51. The second optical member 56 transmits the excitation light E and reflects the fluorescence Y.

[0074] The second optical member 56 includes a second transparent substrate 561 and a second optical layer 562 . Like the first transparent substrate 551, the second transparent substrate 561 is made of a translucent material such as borosilicate glass such as BK7, quartz, synthetic quartz, crystal, SiC, GaN, MgO, YAG, sapphire, and diamond. The second transparent substrate 561 must be made of a material that can transmit at least the excitation light E. The second transparent substrate 561 has a plate-like shape extending along the X-axis. As shown in FIG. 3, the second transparent substrate 561 has a rectangular cross-sectional shape cut along the YZ plane, and extends elongated in the X-axis direction.

[0075] The second optical layer 562 is composed of a dielectric multilayer film similar to the first optical layer 552, and has the optical property of transmitting the excitation light E and reflecting the fluorescence Y. The second optical layer 562 is provided on one of the two surfaces of the second transparent substrate 561, the surface 561a facing the wavelength conversion element 51. With this configuration, as will be described later, the fluorescence Y is reflected by the second optical layer 562 without entering the second transparent substrate 561, thereby suppressing loss of the fluorescence Y due to propagation inside the second transparent substrate 561 and increasing the utilization efficiency of the fluorescence Y.

[0076] Similar to the first optical member 55, the second optical member 56 is pressed against the support member 80 by a pressing member 88. The pressing member 88 is disposed between the second optical member 56 and the top wall portion 33a of the lid 33 of the housing 31. The pressing member 88 abuts against a surface 561b of the second transparent substrate 561 opposite to the second optical layer 562, and does not directly press against the second optical layer 562, thereby suppressing deformation or damage to the second optical layer 562.

[0077] Furthermore, the second optical member 56 covers the -Y side of the second light guiding unit 72 sandwiched between the first support unit 801 and the second support unit 802 in the Z-axis direction. The second optical member 56 is provided straddling the first support unit 801 and the second support unit 802 in the Z-axis direction, and both ends of the second optical member 56 are located on the first support unit 801 and the second support unit 802. Note that the second optical member 56 has a similar configuration to the first optical member 55, and therefore it is considered that defective portions also occur at the ends of the second optical layer 562.

[0078] In light source device 30A of the present embodiment, second optical member 56 straddles between first support section 801 and second support section 802, and therefore the end of second optical layer 562 corresponding to the defective portion is positioned outside the gap between first support section 801 and second support section 802. In the case of the present embodiment, an air layer 712 of first light guiding section 71 is provided in the gap on the −Y side of first support section 801 and second support section 802.

[0079] Furthermore, in the present embodiment, the second optical layer 562 abuts against the first support portion 801 and the second support portion 802, and therefore, as shown in Fig. 3, the defect portion 562K of the second optical layer 562 does not communicate with the air layer 722 located in the gap between the first support portion 801 and the second support portion 802. Therefore, a portion of the fluorescence Y propagating through the air layer 722 is not incident on the defect portion 562K and leaks toward the second light source 42, resulting in loss. Therefore, by suppressing the light loss caused by the defect portion 562K of the second optical layer 562, the light utilization efficiency of the fluorescence Y can be improved.

[0080] Fig. 4 is a plan view of the light source device 30A viewed from the +X side to the -X side. That is, Fig. 4 is a plan view when viewed in the X-axis direction, which is the normal direction of the second end surface 51d along the YZ plane of the wavelength conversion element 51. As shown in Fig. 4, the extraction port 31K overlaps with the first light guiding section 71, the wavelength conversion element 51, and the second light guiding section 72. Therefore, the extraction port 31K of the housing 31 has a shape that exposes the first light guiding section 71, the wavelength conversion element 51, and the second light guiding section 72 to the inside.

[0081] The light source device 30A of this embodiment can extract the yellow fluorescence Y that has propagated through the first light-guiding section 71, the wavelength conversion element 51, and the second light-guiding section 72 through the extraction outlet 31K of the housing 31 and emit it as illumination light WL.

[0082] 1, an integrator optical system 90 is provided on the light emission side of the light source device 30A. The integrator optical system 90 has a first lens array 91 and a second lens array 92. The integrator optical system 90, together with a superimposing optical system 94, functions as a uniform illumination optical system that uniformizes the intensity distribution of the illumination light WL emitted from the light source device 30A in each of the light modulation devices 4R, 4G, and 4B, which are the illuminated regions.

[0083] The first lens array 91 has a plurality of first lenses 91a. The plurality of first lenses 91a are arranged in a matrix in a plane parallel to the YZ plane, which is perpendicular to the optical axis AX1 of the first lighting device 11. The plurality of first lenses 91a split the illumination light WL emitted from the light source device 30A into a plurality of partial light beams. The shape of each of the first lenses 91a is rectangular, which is approximately similar to the shape of the image formation areas of the light modulation devices 4R, 4G, and 4B. This allows each of the partial light beams emitted from the first lens array 91 to efficiently enter the image formation areas of the light modulation devices 4R, 4G, and 4B.

[0084] The illumination light WL emitted from the first lens array 91 travels toward the second lens array 92. The second lens array 92 is disposed opposite the first lens array 91. The second lens array 92 has a plurality of second lenses 92a corresponding to the plurality of first lenses 91a of the first lens array 91. The second lens array 92, together with the superimposing optical system 94, forms each of the images of the plurality of first lenses 91a of the first lens array 91 near the image forming areas of the light modulation devices 4R, 4G, and 4B. The plurality of second lenses 92a are arranged in a matrix in a plane parallel to the YZ plane that is perpendicular to the optical axis AX1 of the first illumination device 11. The superimposing optical system 94 is composed of a single convex lens.

[0085] In this embodiment, the first lenses 91a of the first lens array 91 and the second lenses 92a of the second lens array 92 have the same size, but may have different sizes. Also, in this embodiment, the first lenses 91a of the first lens array 91 and the second lenses 92a of the second lens array 92 are arranged so that their optical axes coincide with each other, but they may be arranged eccentrically with each other.

[0086] The polarization conversion element 93 converts the polarization direction of the illumination light WL emitted from the second lens array 92. Specifically, the polarization conversion element 93 converts each partial beam of the illumination light WL split by the first lens array 91 and emitted from the second lens array 92 into linearly polarized light. The polarization conversion element 93 has a polarization separation layer, a reflective layer, and a retardation layer, all of which are not shown. The polarization separation layer transmits one linearly polarized component of the polarization components contained in the illumination light WL emitted from the light source device 30A as is, and reflects the other linearly polarized component in a direction perpendicular to the optical axis AX1. The reflective layer reflects the other linearly polarized component reflected by the polarization separation layer in a direction parallel to the optical axis AX1. The retardation layer converts the other linearly polarized component reflected by the reflective layer into one linearly polarized component.

[0087] The behavior of light in the light source device 30A of this embodiment will be described below. 2, in the light source device 30A, the excitation light E emitted from the first light source 41 passes through the first optical member 55 and the first light guiding section 71 and enters the wavelength conversion element 51. Furthermore, the excitation light E emitted from the second light source 42 passes through the second optical member 56 and the second light guiding section 72 and enters the wavelength conversion element 51. When the excitation light E enters the wavelength conversion element 51, the phosphor contained inside the wavelength conversion element 51 is excited, and fluorescence Y is emitted in various directions from any light-emitting point.

[0088] Of the fluorescence Y emitted from the wavelength conversion element 51, fluorescence Y1 that is incident on the surface 51a of the wavelength conversion element 51 at an incident angle less than the critical angle is emitted from the wavelength conversion element 51 and enters the first translucent member 711 of the first light-guiding section 71. The fluorescence Y1 is incident on the interface between the first light-transmissive member 711 and the air layer 712 at an incident angle equal to or greater than the critical angle, and is therefore totally reflected and emitted to the outside from the end face 711d on the second end face 51d side of the first light-transmissive member 711. Although not shown in the figures, part of the fluorescence Y that is totally reflected at the interface between the first light-transmissive member 711 and the air layer 712 propagates within the first light-transmissive member 711 by total reflection and is emitted to the outside from the end face 711d on the second end face 51d side of the first light-transmissive member 711.

[0089] Furthermore, the fluorescence Y2 emitted from the wavelength conversion element 51 is incident on the interface between the first light-transmissive member 711 and the air layer 712 at an incident angle less than the critical angle, and thereby passes through the first light-transmissive member 711 and enters the air layer 712. The fluorescence Y2 is reflected by the first optical layer 552 of the first optical member 55, passes through the air layer 712, enters the first light-transmissive member 711 again, and is emitted to the outside from the end face 711d on the second end face 51d side of the first light-transmissive member 711. Although not shown in the drawings, part of the fluorescence Y that has again entered the first light-transmissive member 711 propagates within the first light-transmissive member 711 by total reflection and is emitted to the outside from the end face 711d on the second end face 51d side.

[0090] Furthermore, the fluorescence Y3 emitted from the wavelength conversion element 51 and reaching the first reflecting member 81 is reflected by the first reflecting member 81, then travels toward the +X side, and propagates inside the first light-guiding section 71 by being reflected, for example, between the first optical layer 552 of the first optical member 55 and the first translucent member 711 or the air layer 712, and is emitted to the outside from the area on the second end face 51d side of the first light-guiding section 71.

[0091] Furthermore, of the fluorescence Y emitted from the wavelength conversion element 51, fluorescence Y4 that is incident on the surface 51a of the wavelength conversion element 51 at an incident angle equal to or greater than the critical angle is reflected by the surface 51a and guided inside the wavelength conversion element 51. In this embodiment, since the wavelength conversion element 51 is made of a transparent phosphor, the fluorescence Y4 is not scattered inside the wavelength conversion element 51, and the incident angle of the fluorescence Y4 on the surface 51a or rear surface 51b of the wavelength conversion element 51 does not change. Therefore, the fluorescence Y4 traveling toward the +X side is repeatedly reflected between the surface 51a and rear surface 51b of the wavelength conversion element 51 and is emitted from the second end surface 51d. On the other hand, the fluorescence Y4 traveling toward the -X side is reflected by the first reflecting member 81, like the fluorescence Y3, and then travels toward the +X side, repeatedly reflected between the surface 51a and rear surface 51b of the wavelength conversion element 51, and is emitted from the second end surface 51d.

[0092] In this way, the fluorescence Y emitted from the wavelength conversion element 51 is repeatedly reflected between the wavelength conversion element 51 or the first translucent member 711 of the first light-guiding section 71 and the first optical layer 552 of the first optical member 55, and thereby propagates through the interior of the first translucent member 711 and the air layer 712, and is emitted to the outside from the end face 711d on the second end face 51d side of the first translucent member 711 and the region on the second end face 51d side of the air layer 712.

[0093] In this embodiment, the same can be said about the behavior of the fluorescence Y that is incident on the second light guiding section 72 side from the wavelength conversion element 51 directly or via the first light guiding section 71 or the first optical member 55.

[0094] Therefore, in the light source device 30A of the present embodiment, the fluorescence Y converted by the wavelength conversion element 51 travels through the wavelength conversion element 51, the first light guiding section 71, and the second light guiding section 72, and is emitted from the second end surface 51d of the wavelength conversion element 51, the first light guiding section 71, and the second light guiding section 72. Therefore, according to the light source device 30A of the present embodiment, the illumination light WL containing the fluorescence Y can be efficiently extracted to the outside from the extraction port 31K of the housing 31.

[0095] 2, of the fluorescence Y emitted from the wavelength conversion element 51, the fluorescence Y0 that is incident on the first optical layer 552 or the second optical layer 562 from the normal direction and reflected perpendicularly is unlikely to change its traveling direction while passing through the wavelength conversion element 51, and is repeatedly reflected between the first optical layer 552 and the second optical layer 562. The fluorescence Y0 that is repeatedly reflected between the first optical layer 552 and the second optical layer 562 in this way is absorbed while propagating through the wavelength conversion element 51 multiple times.

[0096] In the light source device 30A of this embodiment, the illumination light WL is extracted to the outside from the extraction port 31K of the housing 31, so that the etendue of the illumination light WL is small, and it is possible to reduce the loss of the illumination light WL in optical members such as the integrator optical system 90 arranged downstream of the light source device 30A. As a result, it is possible to improve the utilization efficiency of the illumination light WL in the light source device 30A.

[0097] (Effects of the first embodiment) The light source device 30A of this embodiment includes a first light source 41 that emits excitation light E, a wavelength conversion element 51 that converts the excitation light E into yellow fluorescence Y, a first optical member 55 that is arranged between the first light source 41 and the wavelength conversion element 51 and that transmits the excitation light E and reflects the fluorescence Y, a first light guiding section 71 that is arranged between the wavelength conversion element 51 and the first optical member 55 and that guides the fluorescence Y converted by the wavelength conversion element 51, a first reflecting member 81 that reflects the excitation light E and the fluorescence Y, and a support member 80 that supports the wavelength conversion element 51. The wavelength conversion element 51 has a surface 51a on which the excitation light E is incident via the first optical member 55 and the first light guiding section 71, a first end face 51c and a second end face 51d that intersect with the surface 51a and face in opposite directions, and a first side face 51e and a second side face 51f that intersect with the surface 51a, the first end face 51c, and the second end face 51d and face in opposite directions. The first reflecting member 81 is disposed on the first end face 51c side of the wavelength conversion element 51 and in an area on the first end face 51c side of the first light guiding section 71. The fluorescence Y converted by the wavelength conversion element 51 travels through the first light guiding section 71 and is emitted from an area on the second end face 51d side of the first light guiding section 71. The support member 80 has a first support portion 801 that supports the first side surface 51e of the wavelength conversion element 51 and a second support portion 802 that supports the second side surface 51f of the wavelength conversion element 51. The first optical member 55 abuts against the first support portion 801 and the second support portion 802, and covers the side of the first light guiding portion 71 that is disposed between the first support portion 801 and the second support portion 802 opposite to the wavelength conversion element 51. The light source device 30A of this embodiment further includes: a second light source 42 that is disposed on the opposite side of the wavelength conversion element 51 from the first light source 41 and that emits excitation light E; a second optical member 56 that is disposed between the second light source 42 and the wavelength conversion element 51 and that transmits the excitation light E and reflects the fluorescence Y; and a second light guiding unit 72 that is disposed between the wavelength conversion element 51 and the second optical member 56 and that guides the fluorescence Y converted by the wavelength conversion element 51. The fluorescence Y converted by the wavelength conversion element 51 travels through the second light guiding unit 72 and is emitted from a region of a second end surface 51d of the second light guiding unit 72. The second optical member 56 abuts against the first support member 801 and the second support member 802 and covers a side of the second light guiding unit 72 that is disposed between the first support member 801 and the second support member 802 and that is opposite to the wavelength conversion element 51.

[0098] According to the light source device 30A of the present embodiment, the fluorescence Y generated by the wavelength conversion element 51 travels through the first light guiding section 71 and is emitted from the end face 711d of the first light-transmissive member 711 on the second end face 51d side and the region of the air layer 712 on the second end face 51d side. Also, the fluorescence Y generated by the wavelength conversion element 51 travels through the second light guiding section 72 and is emitted from the end face 721d of the second light-transmissive member 721 on the second end face 51d side and the region of the air layer 722 on the second end face 51d side. Therefore, the light source device 30A of this embodiment has less loss of the fluorescence Y and can improve the utilization efficiency of the fluorescence Y compared to conventional light source devices that extract fluorescence by propagating it inside the wavelength conversion element only by total reflection.

[0099] Furthermore, in the light source device 30A of the present embodiment, the first optical member 55 covers the first light guiding section 71 on the side opposite to the wavelength conversion element 51, and the second optical member 56 covers the second light guiding section 72 on the side opposite to the wavelength conversion element 51. Therefore, a defect portion 552K occurring at the end of the first optical layer 552 and a defect portion 562K occurring at the end of the second optical layer 562 are not in communication with the air layers 712, 722 between the first support portion 801 and the second support portion 802. This prevents a portion of the fluorescence Y propagating through the air layers 712, 722 from entering the defect portions 552K, 562K and becoming a light loss, thereby further improving the light use efficiency of the fluorescence Y.

[0100] Furthermore, in the present embodiment, the air layers 712, 722 are open to the external space at the outlet 31K and do not have a refractive index interface, so the fluorescence Y that reaches the outlet 31K through the air layers 712, 722 is emitted directly into the external space without being reflected or refracted. Therefore, by including the air layers 712, 722 in the first light guiding section 71 and the second light guiding section 72, the extraction efficiency of the fluorescence Y can be increased.

[0101] The projector 1 of this embodiment includes a light source device 30A, light modulation devices 4R, 4G, and 4B that modulate the light emitted from the light source device 30A, and a projection optical device 6 that projects the light modulated by the light modulation devices 4R, 4G, and 4B.

[0102] The projector 1 of this embodiment has excellent light utilization efficiency because it is equipped with the first illumination device 11 including the light source device 30A that efficiently extracts illumination light WL containing fluorescence Y.

[0103] (Second embodiment) A second embodiment of the present invention will be described below with reference to FIG. The basic configuration of the light source device of the second embodiment is similar to that of the first embodiment, and therefore a description of the basic configuration of the light source device will be omitted. 5 is a cross-sectional view of a light source device 30B of the second embodiment cut along the XY plane. In FIG. 5, components common to those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

[0104] As shown in FIG. 5, the light source device 30B of this embodiment includes a housing 31, a first light source 41, a second light source 42, a wavelength conversion element 52, a first optical member 55, a second optical member 56, a first light guiding section 71, a second light guiding section 72, a support member 80, a pressing member 88, a first reflecting member 81, and a second reflecting member and a third reflecting member (not shown).

[0105] In the light source device 30A of the first embodiment, the wavelength conversion element 51 is made of a transparent phosphor. In contrast, in the light source device 30B of the present embodiment, the wavelength conversion element 52 is made of a phosphor with light-scattering properties. A phosphor with light-scattering properties can be realized by dispersing a medium with a refractive index different from that of the transparent phosphor, such as pores or a filler, in the transparent phosphor. The wavelength conversion element 52 has a front surface 52a and a back surface 52b, a first end surface 52c and a second end surface 52d, a first side surface 52e and a second side surface 52f. The other configurations of the light source device 30B are similar to those of the light source device 30A of the first embodiment. The surface 52a, the first end surface 52c, the second end surface 52d, the first side surface 52e, and the second side surface 52f of this embodiment correspond to examples of the "first surface, second surface, third surface, fourth surface, and fifth surface" of the present invention, respectively.

[0106] (Effects of the second embodiment) In the present embodiment, the same effects as in the first embodiment can be obtained, such as realizing a light source device 30B that has little loss of fluorescence Y and excellent utilization efficiency of fluorescence Y, and that can efficiently emit illumination light WL, by propagating fluorescence Y through the first light guiding section 71 and the second light guiding section 72. Furthermore, the same effects as in the first embodiment can be obtained, such as realizing a light source device 30B that can further improve the light utilization efficiency of fluorescence Y by suppressing the incidence of a portion of fluorescence Y propagating through the air layers 712, 722 on the defect sites 552K, 562K.

[0107] In the first embodiment, since the wavelength conversion element 51 is made of a transparent phosphor, the direction of the fluorescence Y emitted from the wavelength conversion element 51, that is fluorescence Y0 (see Figure 2) that is incident perpendicularly on the first optical layer 552 or the second optical layer 562, is unlikely to change within the wavelength conversion element 51, and is repeatedly reflected between the first optical layer 552 and the second optical layer 562, resulting in loss.

[0108] In contrast, in the case of the light source device 30B of this embodiment, the wavelength conversion element 52 is made of a phosphor having light-scattering properties, so that when the fluorescence Y reflected by the first optical layer 552 or the second optical layer 562 enters the wavelength conversion element 52, a lot of scattering occurs, and the traveling direction of the fluorescence Y changes with each scattering, as shown in FIG.

[0109] For this reason, even if the fluorescence Y0 is reflected by the first optical layer 552 and perpendicularly incident on the wavelength conversion element 52, it is scattered within the wavelength conversion element 52 and undergoes angle conversion, so that it eventually propagates through the first light guiding unit 71 and is emitted from the end face 711d on the second end face 51d side of the first light-transmissive member 711 and the region on the second end face 51d side of the air layer 712. Alternatively, it propagates through the second light guiding unit 72 and is emitted from the end face 721d on the second end face 51d side of the second light-transmissive member 721 and the region on the second end face 51d side of the air layer 722.

[0110] As described above, in the light source device 30B of the present embodiment, the fluorescence Y propagates through the first light guiding unit 71 while repeating at least one of scattering by the wavelength conversion element 52, reflection by the first optical layer 552 of the first optical member 55, and reflection on the surface of the first light-transmissive member 711 that is in contact with the air layer 712, and is emitted from a region on the second end face 51d side of the first light guiding unit 71. Furthermore, the fluorescence Y propagates through the second light guiding unit 72 while repeating at least one of scattering by the wavelength conversion element 52, reflection by the second optical layer 562 of the second optical member 56, and reflection on the surface of the second light-transmissive member 721 that is in contact with the air layer 722, and is emitted from a region on the second end face 51d side of the second light guiding unit 72.

[0111] In the present embodiment, almost no fluorescence Y exists that is not emitted to the outside by propagating inside the wavelength conversion element 52. Therefore, according to the light source device 30B of the present embodiment, the fluorescence Y can be efficiently extracted as illumination light WL.

[0112] The wavelength conversion element 52 made of a phosphor having light scattering properties is more likely to reabsorb the fluorescence Y that passes through it than the wavelength conversion element 51 of the first embodiment made of a transparent phosphor. For this reason, it is desirable to make the dimension of the wavelength conversion element 52 in the X-axis direction, which is the direction in which the fluorescence Y is extracted, shorter than that of the wavelength conversion element 51 of the first embodiment. The X-axis direction corresponds to the longitudinal direction of the wavelength conversion element 52. According to the light source device 30B of this embodiment, the longitudinal dimension of the wavelength conversion element 52 can be made shorter than that of the configuration of the first embodiment, while the light utilization efficiency of the fluorescent light Y can be improved. Therefore, the light source device 30B of this embodiment can realize a light source device that improves the light utilization efficiency of the fluorescent Y while reducing the size of the device configuration.

[0113] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, a composite phosphor containing, for example, AlN and Ce:YAG may be used as the constituent material of the first wavelength conversion element. With this configuration, even if the contact area between the first wavelength conversion element and the housing is small and many heat dissipation paths cannot be secured, the thermal conductivity of the first wavelength conversion element can be increased compared to when a phosphor consisting solely of Ce:YAG is used. This improves the cooling efficiency of the first wavelength conversion element. This increases the maximum light intensity of the first excitation light and the maximum output of yellow fluorescence. Similarly, a composite phosphor may also be used for the second wavelength conversion element.

[0114] Although the light source devices of the above embodiments all include a second light source, they may be configured to include only a first light source. In this case, the second light guiding section 72 and the second optical member 56 may be omitted. In this case, the housing 31 may be configured to support the rear surface 52b of the wavelength conversion element 51.

[0115] Although the first and second light guiding sections of the light source device in the above embodiments are both made of a light-transmitting member and an air layer, at least one of the first and second light guiding sections may be made of only an air layer, or at least one of the first and second light guiding sections may be made of only a light-transmitting member.

[0116] In addition, the specific descriptions of the shape, number, arrangement, materials, etc. of each component of the light source device and the projector are not limited to the above-described embodiments and can be modified as appropriate. Furthermore, in the above-described embodiments, an example was shown in which the light source device according to the present invention was mounted in a projector using a liquid crystal panel, but this is not limiting. The light source device according to the present invention may also be applied to a projector using a digital micromirror device as a light modulation device. Furthermore, the projector does not need to have multiple light modulation devices, and may have only one light modulation device.

[0117] In the above embodiment, the light source device of the present invention is applied to a projector, but the present invention is not limited to this. The light source device of the present invention can also be applied to lighting fixtures, automobile headlights, and the like.

[0118] Summary of this disclosure A summary of this disclosure is provided below.

[0119] (Appendix 1) a first light source that emits first light in a first wavelength band; a wavelength conversion element that converts the first light into second light in a second wavelength band different from the first wavelength band; a first optical member disposed between the first light source and the wavelength conversion element, the first optical member transmitting the first light and reflecting the second light; a first light guiding section disposed between the wavelength conversion element and the first optical member, which guides the second light converted by the wavelength conversion element; a first reflecting member that reflects the first light and the second light; a support member for supporting the wavelength conversion element; Equipped with the wavelength conversion element has a first surface onto which the first light is incident via the first optical member and the first light guiding portion, a second surface and a third surface that intersect with the first surface and face in opposite directions to each other, and a fourth surface and a fifth surface that intersect with the first surface, the second surface, and the third surface and face in opposite directions to each other, the first reflecting member is disposed on the second surface side of the wavelength conversion element and in an area on the second surface side of the first light guiding section, the second light converted by the wavelength conversion element travels through the first light guiding section and is emitted from a region on the third surface side of the first light guiding section, the support member has a first support portion that supports the fourth surface of the wavelength conversion element and a second support portion that supports the fifth surface of the wavelength conversion element, the first optical member abuts against the first support portion and the second support portion, and covers a side of the first light guiding portion disposed between the first support portion and the second support portion opposite to the wavelength conversion element. Light source device.

[0120] According to the light source device having this configuration, the second light generated by the wavelength conversion element travels through the first light guiding section and is emitted from the region on the third surface side of the first light guiding section. Therefore, the light source device having this configuration has less loss of the second light and can improve light utilization efficiency compared to conventional light source devices that extract the second light by propagating it inside the wavelength conversion element only by total reflection. Furthermore, in the light source device having this configuration, because the first optical member covers the side of the first light guiding unit opposite to the wavelength conversion element, a defect portion occurring at the end of the first optical member is not in communication with the first light guiding unit located between the first support unit and the second support unit, which prevents a portion of the second light propagating through the first light guiding unit from entering the defect portion and causing light loss, thereby further improving the light utilization efficiency of the second light.

[0121] (Appendix 2) the first optical member includes a first transparent substrate that transmits the first light, and a first optical layer that is provided on a surface of the first light-transmitting substrate facing the wavelength conversion element and transmits the first light and reflects the second light. 10. The light source device of claim 1.

[0122] According to this configuration, by forming the first optical layer on the flat first light-transmissive member, the first optical layer can be formed as a flat film. Also, since the second light is reflected by the first optical layer without entering the first light-transmissive member, it is possible to suppress loss caused by the second light propagating within the first light-transmissive member.

[0123] (Appendix 3) the first light guiding portion is disposed on the first surface of the wavelength conversion element and includes a first light-transmitting member that transmits the first light and the second light; the second light converted by the wavelength conversion element propagates through the first light-transmitting member and is emitted from an end face of the first light-transmitting member on the third surface side. 10. The light source device according to claim 1 or 2.

[0124] According to this configuration, the difference in refractive index between the wavelength conversion element and the light guiding section is small, and the critical angle at the interface between the wavelength conversion element and the light guiding section is small. This makes it easier to extract the second light generated by the wavelength conversion element to the first light guiding section, and reduces loss due to re-absorption of the second light.

[0125] (Appendix 4) the first light guiding section further includes an air layer provided between the first light-transmissive member and the first optical member, the second light converted by the wavelength conversion element propagates through the first light-transmitting member and the air layer, and is emitted from an end face of the first light-transmitting member on the third surface side and a region of the air layer on the third surface side. 4. The light source device according to claim 3.

[0126] According to this configuration, the second light is refracted when it is emitted from the first light-transmissive member, so that it travels in a direction that forms a small angle with respect to the longitudinal direction of the wavelength conversion element. Furthermore, since the air layer on the third surface side is open to the outside and does not have a refractive index interface, the second light that reaches the region on the third surface side is emitted directly into the external space without being reflected or refracted. Therefore, the extraction efficiency of the second light can be improved.

[0127] (Appendix 5) the first light-transmitting member and the first surface of the wavelength conversion element are fixed together with a light-transmitting adhesive; 5. The light source device according to claim 3 or 4.

[0128] According to this configuration, the first light-transmissive member and the wavelength conversion element are joined together, so there is no air gap between them. Therefore, the second light emitted from the wavelength conversion element is less likely to be totally reflected at the interface with the first light-transmissive member, and is efficiently incident on the first light-transmissive member. Therefore, the first light guide can efficiently take in the second light.

[0129] (Appendix 6) The refractive index of the first light-transmissive member is smaller than the refractive index of the wavelength conversion element. 5. The light source device according to claim 3 or 4.

[0130] According to this configuration, the second light is refracted when it enters the first light-transmissive member from the wavelength conversion element, thereby reducing the angle it forms with the major axis of the first light-transmissive member. In other words, the second light propagating through the first light-transmissive member is incident at a small angle with respect to a plane perpendicular to the major axis. Therefore, the first light-transmissive member can efficiently extract the second light from the end face on the third surface side.

[0131] (Appendix 7) a housing that accommodates the wavelength conversion element, the first optical member, and the support member; a pressing member disposed between the first optical member and the housing and configured to press the first optical member against the support member; Further provided with 7. A light source device according to any one of claims 1 to 6.

[0132] According to this configuration, the first optical member abuts against the support member, so that the side of the first light guide opposite to the wavelength conversion element can be satisfactorily covered.

[0133] (Appendix 8) a housing that accommodates the wavelength conversion element, the first optical member, and the support member; the housing has an outlet through which the second light emitted from the region on the third surface side of the first light guide section is extracted to the outside, the extraction port overlaps the first light guiding unit and the wavelength conversion element in a planar view in a normal direction of the third surface of the wavelength conversion element. 8. A light source device according to any one of claims 1 to 7.

[0134] With this configuration, the housing can protect the first optical member, the first light guide section, the wavelength conversion element, and the first reflecting member, and the second light propagating inside the first light guide section can be extracted to the outside as illumination light through the extraction port of the housing.

[0135] (Appendix 9) further comprising a second reflecting member and a third reflecting member that reflect the first light and the second light, the second reflecting member is provided on a surface of the first support portion that faces the fourth surface of the wavelength conversion element and a region of the first light guiding portion on the fourth surface side, the third reflecting member is provided on a surface of the second support portion facing the fifth surface of the wavelength conversion element and a region of the first light guiding portion on the fifth surface side; 9. A light source device according to any one of claims 1 to 8.

[0136] This configuration can increase the efficiency of converting the first light into the second light by the second reflecting member and the third reflecting member, and can also reduce the loss of each light beam emitted from the fourth and fifth surfaces and absorbed by the housing.

[0137] (Appendix 10) The wavelength conversion element is made of a transparent phosphor. 10. A light source device according to any one of claims 1 to 9.

[0138] According to this configuration, even when a wavelength conversion element made of a transparent phosphor is used, it is possible to realize a light source device that efficiently extracts the second light from the third surface side of the first light guiding section to the outside.

[0139] (Appendix 11) The wavelength conversion element is made of a phosphor having light scattering properties. 10. A light source device according to any one of claims 1 to 9.

[0140] According to this configuration, the propagation direction of the second light changes in various directions due to the scattering of light by the wavelength conversion element, and the second light can be efficiently emitted from the region on the third surface side after propagating inside the first light guiding section, thereby reducing loss of the second light and further increasing the light extraction efficiency of the second light.

[0141] (Appendix 12) the wavelength conversion element includes a yellow phosphor; the first light is blue light; the second light is yellow fluorescent light, the first light guiding unit is disposed on the first surface of the wavelength conversion element and includes a first translucent member that transmits the first light and the second light, and an air layer that is disposed between the first translucent member and the first optical member, the fluorescent light propagates through the first light-transmitting member and the air layer while repeating at least one of reflection by the wavelength conversion element, reflection by the first optical member, and reflection on a surface of the first light-transmitting member that is in contact with the air layer, and is emitted from an end face of the first light-transmitting member on the third surface side and a region of the air layer on the third surface side. 11. The light source device of claim 10.

[0142] According to this configuration, the yellow fluorescence generated by the wavelength conversion element can be efficiently extracted from the region on the third surface side of the first light guiding section.

[0143] (Appendix 13) the wavelength conversion element includes a yellow phosphor; the first light is blue light; the second light is yellow fluorescent light, the first light guiding unit is disposed on the first surface of the wavelength conversion element and includes a first translucent member that transmits the first light and the second light, and an air layer that is disposed between the first translucent member and the first optical member, the fluorescent light propagates through the first light-transmitting member and the air layer while repeating at least one of scattering by the wavelength conversion element, reflection by the first optical member, and reflection on a surface of the first light-transmitting member that is in contact with the air layer, and is emitted from an end face of the first light-transmitting member on the third surface side and a region of the air layer on the third surface side. 12. The light source device according to claim 11.

[0144] According to this configuration, the fluorescence can be scattered by the wavelength conversion element.

[0145] (Appendix 14) a second light source that is disposed on the opposite side of the wavelength conversion element from the first light source and that emits the first light; a second optical member disposed between the second light source and the wavelength conversion element, the second optical member transmitting the first light and reflecting the second light; a second light guiding section disposed between the wavelength conversion element and the second optical member, which guides the second light converted by the wavelength conversion element; Furthermore, the second light converted by the wavelength conversion element travels through the second light guiding section and is emitted from a region on the third surface side of the second light guiding section, the second optical member abuts against the first support portion and the second support portion, and covers a side of the second light guiding portion disposed between the first support portion and the second support portion opposite to the wavelength conversion element. 14. A light source device according to any one of claims 1 to 13.

[0146] According to this configuration, the second light generated by the wavelength conversion element travels through the second light guiding section and is emitted from the region on the third surface side of the second light guiding section, thereby further improving the light utilization efficiency of the second light. Furthermore, because the second optical member covers the side of the second light guiding section opposite the wavelength conversion element, a defect portion occurring at the end of the second optical member is not in communication with the second light guiding section located between the first support section and the second support section. This prevents a portion of the second light propagating through the second light guiding section from entering the defect portion and causing light loss, thereby further improving the light utilization efficiency of the second light.

[0147] (Appendix 15) a light source device according to any one of Supplementary Note 1 to Supplementary Note 14; a light modulation device that modulates the light emitted from the light source device; a projection optical device that projects the light modulated by the light modulation device; A projector equipped with

[0148] According to a projector having this configuration, since it is equipped with a light source device that extracts light efficiently, it is possible to provide a projector with excellent light utilization efficiency. [Explanation of symbols]

[0149] 1...projector, 30A, 30B...light source device, 4B, 4G, 4R...light modulation device, 6...projection optical device, 31...housing, 31K...extraction port, 41...first light source, 42...second light source, 51, 52...wavelength conversion element, 51a, 52a...surface (first surface), 51c, 52c...first end surface (second surface), 51d, 52d...second end surface (third surface), 51e, 52e...first side surface (fourth surface), 51f, 52f...second side surface (fifth surface), 55...first optical member, 56...second optical member, 71...first guide Light section, 72...second light guiding section, 80...support member, 81...first reflecting member, 82...second reflecting member, 83...third reflecting member, 88...pressing member, 711...first light-transmitting member, 551a, 551b, 561a, 561b...surface, 551...first transparent substrate, 552...first optical layer, 711d, 721d...end face, 712, 722...air layer, 713...light-transmitting adhesive, 801...first supporting section, 802...second supporting section, E...excitation light (first light), Y, Y0, Y1, Y2, Y3, Y4...fluorescence (second light).

Claims

1. a first light source that emits first light in a first wavelength band; a wavelength conversion element that converts the first light into second light in a second wavelength band different from the first wavelength band; a first optical member disposed between the first light source and the wavelength conversion element, the first optical member transmitting the first light and reflecting the second light; a first light guiding section disposed between the wavelength conversion element and the first optical member, which guides the second light converted by the wavelength conversion element; a first reflecting member that reflects the first light and the second light; a support member for supporting the wavelength conversion element; Equipped with the wavelength conversion element has a first surface onto which the first light is incident via the first optical member and the first light guiding portion, a second surface and a third surface intersecting the first surface and facing in opposite directions to each other, and a fourth surface and a fifth surface intersecting the first surface, the second surface, and the third surface and facing in opposite directions to each other, the first reflecting member is disposed in an area on the second surface side of the wavelength conversion element and on the second surface side of the first light guiding section, the second light converted by the wavelength conversion element travels through the first light guiding section and is emitted from a region on the third surface side of the first light guiding section, the support member has a first support portion that supports the fourth surface of the wavelength conversion element and a second support portion that supports the fifth surface of the wavelength conversion element, the first optical member abuts against the first support portion and the second support portion, and covers a side of the first light guiding portion disposed between the first support portion and the second support portion opposite to the wavelength conversion element; Light source device.

2. the first optical member includes a first transparent substrate that transmits the first light, and a first optical layer that is provided on a surface of the first transparent substrate that faces the wavelength conversion element and transmits the first light and reflects the second light. The light source device according to claim 1 .

3. the first light guiding unit is disposed on the first surface of the wavelength conversion element and includes a first light-transmitting member that transmits the first light and the second light; the second light converted by the wavelength conversion element propagates through the first light-transmitting member and is emitted from an end face of the first light-transmitting member on the third surface side. The light source device according to claim 1 .

4. the first light guiding unit further includes an air layer provided between the first light-transmissive member and the first optical member, the second light converted by the wavelength conversion element propagates through the first light-transmitting member and the air layer, and is emitted from an end face of the first light-transmitting member on the third surface side and a region of the air layer on the third surface side. The light source device according to claim 3 .

5. the first light-transmitting member and the first surface of the wavelength conversion element are fixed together with a light-transmitting adhesive; The light source device according to claim 3 .

6. The refractive index of the first light-transmissive member is smaller than the refractive index of the wavelength conversion element. The light source device according to claim 3 .

7. a housing that accommodates the wavelength conversion element, the first optical member, and the support member; a pressing member disposed between the first optical member and the housing and configured to press the first optical member against the support member; Further provided with The light source device according to claim 1 .

8. a housing that accommodates the wavelength conversion element, the first optical member, and the support member; the housing has an outlet through which the second light emitted from the region on the third surface side of the first light guide section is extracted to the outside, In a planar view in a normal direction of the third surface of the wavelength conversion element, the extraction port overlaps the first light guiding unit and the wavelength conversion element. The light source device according to claim 1 .

9. further comprising a second reflecting member and a third reflecting member that reflect the first light and the second light, the second reflecting member is provided on a surface of the first support portion that faces the fourth surface of the wavelength conversion element and a region of the first light guiding portion on the fourth surface side, the third reflecting member is provided on a surface of the second support portion facing the fifth surface of the wavelength conversion element and a region of the first light guiding portion on the fifth surface side; The light source device according to claim 1 .

10. The wavelength conversion element is made of a transparent phosphor. The light source device according to claim 1 .

11. The wavelength conversion element is made of a phosphor having light scattering properties. The light source device according to claim 1 .

12. the wavelength conversion element includes a yellow phosphor; the first light is blue light, the second light is yellow fluorescent light, the first light guiding unit is disposed on the first surface of the wavelength conversion element and includes a first translucent member that transmits the first light and the second light, and an air layer that is disposed between the first translucent member and the first optical member, the fluorescent light propagates through the first light-transmitting member and the air layer while repeating at least one of reflection by the wavelength conversion element, reflection by the first optical member, and reflection on a surface of the first light-transmitting member that is in contact with the air layer, and is emitted from an end face of the first light-transmitting member on the third surface side and a region of the air layer on the third surface side. The light source device according to claim 10.

13. the wavelength conversion element includes a yellow phosphor; the first light is blue light, the second light is yellow fluorescent light, the first light guiding unit is disposed on the first surface of the wavelength conversion element and includes a first translucent member that transmits the first light and the second light, and an air layer that is disposed between the first translucent member and the first optical member, the fluorescent light propagates through the first light-transmitting member and the air layer while repeating at least one of scattering by the wavelength conversion element, reflection by the first optical member, and reflection on a surface of the first light-transmitting member that is in contact with the air layer, and is emitted from an end face of the first light-transmitting member on the third surface side and a region of the air layer on the third surface side. The light source device according to claim 11.

14. a second light source that is disposed on the opposite side of the wavelength conversion element from the first light source and that emits the first light; a second optical member disposed between the second light source and the wavelength conversion element, the second optical member transmitting the first light and reflecting the second light; a second light guiding section disposed between the wavelength conversion element and the second optical member, which guides the second light converted by the wavelength conversion element; Furthermore, the second light converted by the wavelength conversion element travels through the second light guiding section and is emitted from a region on the third surface side of the second light guiding section, the second optical member abuts against the first support portion and the second support portion, and covers a side of the second light guiding portion disposed between the first support portion and the second support portion opposite to the wavelength conversion element. The light source device according to claim 1 .

15. The light source device according to any one of claims 1 to 6, a light modulation device that modulates the light emitted from the light source device; a projection optical device that projects the light modulated by the light modulation device, projector.

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