Light source device and projector

Abstract

A light source device and a projector have high light utilization efficiency. The light source device includes: a first light source that emits first light of a first wavelength band; a wavelength conversion element that converts the first light into second light of a second wavelength band different from the first wavelength band; a first translucent member that is disposed between the first light source and the wavelength conversion element and that guides the second light converted by the wavelength conversion element; a first optical layer that is disposed between the first light source and the first translucent member and that transmits the first light and reflects the second light; and a first reflection member that reflects the first light and the second light. The wavelength conversion element has a first surface on which the first light is incident through the first optical layer and the first translucent member. The first translucent member has a second surface that faces the first surface, and a third surface and a fourth surface that intersect the second surface and face opposite sides to each other. The third surface faces the first reflective member. The second light converted by the wavelength conversion element travels inside the first translucent member and is emitted from the fourth surface.

Description

Technical Field

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

[0002] As a light source device for a projector, a light source device that utilizes fluorescence emitted from a fluorescent body when excitation light emitted from a light-emitting element is irradiated onto the fluorescent body is proposed. The following patent document 1 discloses a light source device having a flat wavelength conversion component containing a fluorescent body and a light-emitting diode (LED) that emits excitation light, wherein the excitation light is incident from a larger incident surface among multiple surfaces of the wavelength conversion component, and the fluorescence is emitted from a smaller emission surface of the wavelength conversion component.

[0003] Patent Document 1: International Publication No. 2006 / 054203

[0004] In the above light source device, the generated fluorescence is totally reflected at the interface between the surface of the wavelength conversion component and the air layer, and then travels inside the wavelength conversion component and is emitted from the emission surface. However, the components of the fluorescence that are not totally reflected at the interface between the wavelength conversion component and the air layer become leakage light, thereby reducing the light utilization efficiency. Summary of the invention

[0005] In order to solve the above-mentioned problems, a light source device according to one embodiment of the present invention includes: a first light source that emits a first light of a first wavelength band; a wavelength conversion element that converts the first light into a second light of a second wavelength band different from the first wavelength band; a first light-transmitting component that is arranged between the first light source and the wavelength conversion element and guides the second light converted by the wavelength conversion element; a first optical layer that is arranged between the first light source and the first light-transmitting component and transmits the first light and reflects the second light; and a first reflecting component that reflects the first light and the second light. The wavelength conversion element has a first surface for the first light to enter through the first optical layer and the first light-transmitting component. The first light-transmitting component has a second surface that is opposite to the first surface; and a third surface and a fourth surface that intersect the second surface and face opposite sides to each other. The third surface is opposite to the first reflecting component. The second light converted by the wavelength conversion element travels inside the first light-transmitting component and is emitted from the fourth surface.

[0006] A projector according to one embodiment of the present invention includes: the light source device according to the above embodiment; a light modulation device that modulates light from the light source device; and a projection optical device that projects the light modulated by the light modulation device. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0008] Figure 2 It is a side sectional view showing a schematic structure of the first lighting device.

[0009] Figure 3 yes Figure 2 Cross-sectional view taken along line III-III.

[0010] Figure 4 It is a diagram for explaining the behavior of light in the light source device.

[0011] Figure 5 This is a plan view of the light source device viewed from the +X side toward the -X side.

[0012] Figure 6 It is a cross-sectional view showing a schematic structure of a light source device according to a second embodiment.

[0013] Figure 7 It is a cross-sectional view showing a schematic structure of a light source device according to a third embodiment.

[0014] Figure 8 It is a cross-sectional view showing a schematic structure of a light source device according to a fourth embodiment.

[0015] Description of symbols

[0016] 1: projector; 4B, 4G, 4R: light modulator; 6: projection optical device; 30: supporting member; 31, 131: housing; 31k, 131k: guide port; 33: supporting portion; 41, 141: first light source; 42: second light source; 50, 150, 250: wavelength conversion element; 50a: surface (first surface); 50b: back surface (seventh surface); 51: first light-transmitting member; 51a: back surface (second surface); 51c: first end surface (third surface); 51d: second end surface (fourth surface); 51e : First side surface (fifth surface); 51f: Second side surface (sixth surface); 52, 252: First optical layer; 53, 153: First reflecting component; 54: Second reflecting component; 100, 101, 102, 103: Light source device; 151: Second light-transmitting component; 151b: Back surface (eighth surface); 151c: First end surface (ninth surface); 151d: Second end surface (tenth surface); 152: Second optical layer; E: Excitation light (first light); Ur: Ultraviolet light (first light); BY, Y: Fluorescence (second light). DETAILED DESCRIPTION

[0017] (First Embodiment)

[0018] Hereinafter, a first embodiment of the present invention will be described.

[0019] The projector of this embodiment is an example of a projector using a liquid crystal panel as a light modulation device.

[0020] In the following drawings, in order to make each component easier to see, the scale of the dimensions may be different depending on the component.

[0021] Figure 1 1 is a diagram showing a schematic configuration of a projector 1 according to the present embodiment.

[0022] like Figure 1 As shown, the projector 1 of this embodiment is a projection type image display device that displays a color image on a screen SCR as a projection surface. The projector 1 has three light modulators corresponding to the respective color lights of red light LR, green light LG, and blue light LB.

[0023] The projector 1 includes a first illumination device 20 , a second illumination device 21 , a color separation optical system 3 , a light modulation device 4R, a light modulation device 4G, a light modulation device 4B, a light synthesis element 5 , and a projection optical device 6 .

[0024] The first illumination device 20 emits yellow fluorescence Y toward the color separation optical system 3. The second illumination device 21 emits blue light LB toward the light modulator 4B. The detailed structures of the first illumination device 20 and the second illumination device 21 will be described later.

[0025] In the following drawings, the XYZ orthogonal coordinate system is used for explanation as needed. The Z axis is an axis along the vertical direction of the projector 1. The X axis is an axis parallel to the optical axis AX1 of the first lighting device 20 and the optical axis AX2 of the second lighting device 21. The Y axis is an axis orthogonal to the X axis and the Z axis. The optical axis AX1 of the first lighting device 20 is the center axis of the fluorescent light Y emitted from the first lighting device 20. The optical axis AX2 of the second lighting device 21 is the center axis of the blue light LB emitted from the second lighting device 21. One of the two directions along the X axis is called the +X direction, and the opposite direction thereof is called the -X direction, one of the two directions along the Y axis is called the +Y direction, and the opposite direction thereof is called the -Y direction, one of the two directions along the Z axis is called the +Z direction, and the opposite direction thereof is called the -Z direction. In addition, when the two directions along the X axis are collectively referred to without distinguishing them, they are referred to as the X axis direction, when the two directions along the Y axis are collectively referred to without distinguishing them, they are referred to as the Y axis direction, and when the two directions along the Z axis are collectively referred to without distinguishing them, they are referred to as the Z axis direction.

[0026] The color separation optical system 3 separates the yellow fluorescence Y emitted from the first illumination device 20 into red light LR and green light LG. The color separation optical system 3 includes a dichroic mirror 7, a first reflection mirror 8a, and a second reflection mirror 8b.

[0027] The dichroic mirror 7 separates the fluorescence Y 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 reflector 8b is arranged in the optical path of the green light LG. The second reflector 8b reflects the green light LG reflected by the dichroic mirror 7 toward the light modulator 4G. The first reflector 8a is arranged in the optical path of the red light LR. The first reflector 8a reflects the red light LR transmitted by the dichroic mirror 7 toward the light modulator 4R.

[0028] On the other hand, the blue light LB emitted from the second illumination device 21 is reflected by the reflection mirror 9 toward the light modulation device 4B.

[0029] Next, the structure of the second lighting device 21 will be described.

[0030] The second lighting device 21 includes a light source unit 81, a condenser lens 82, a diffusion plate 83, a rod lens 86, and a relay lens 87. The light source unit 81 is composed of at least one semiconductor laser. The light source unit 81 emits blue light LB composed of laser light. In addition, the light source unit 81 is not limited to a semiconductor laser, and can also be composed of an LED that emits blue light.

[0031] The condenser lens 82 is composed of a convex lens. The condenser lens 82 allows the blue light LB emitted from the light source unit 81 to enter the diffuser plate 83 in a substantially condensed state. The diffuser plate 83 diffuses the blue light LB emitted from the condenser lens 82 at a predetermined diffusion degree, and generates the blue light LB having a substantially uniform light distribution similar to the fluorescent light Y emitted from the first lighting device 20. As the diffuser plate 83, for example, frosted glass composed of optical glass is used.

[0032] The blue light LB diffused by the diffuser 83 is incident on the rod lens 86. The rod lens 86 has a prism shape extending along the optical axis AX2 direction of the second lighting device 21. The rod lens 86 has a light incident end face 86a provided at one end and a light emitting end face 86b provided at the other end. The diffuser 83 is fixed to the light incident end face 86a of the rod lens 86 via an optical adhesive (not shown). It is preferred that the refractive index of the diffuser 83 and the refractive index of the rod lens 86 are as consistent as possible.

[0033] The blue light LB is totally reflected and propagated inside the rod lens 86, and is emitted from the light emission end surface 86b in a state where the uniformity of the illumination distribution is improved. The blue light LB emitted from the rod lens 86 is incident on the relay lens 87. The relay lens 87 allows the blue light LB with the uniformity of the illumination distribution improved by the rod lens 86 to be incident on the reflector 9.

[0034] The shape of the light emitting end surface 86b of the rod lens 86 is a rectangle substantially similar to the shape of the image forming region of the light modulator 4B. Thus, the blue light LB emitted from the rod lens 86 is efficiently incident on the image forming region of the light modulator 4B.

[0035] The light modulator 4R modulates the red light LR according to the image information to form image light corresponding to the red light LR. The light modulator 4G modulates the green light LG according to the image information to form image light corresponding to the green light LG. The light modulator 4B modulates the blue light LB according to the image information to form image light corresponding to the blue light LB.

[0036] The light modulators 4R, 4G, and 4B each use a transmissive liquid crystal panel, for example. Polarizers (not shown) are disposed on the incident and exiting sides of the liquid crystal panel, respectively. The polarizer allows only linearly polarized light in a specific direction to pass through.

[0037] A field lens 10R is arranged on the incident side of the light modulator 4R. A field lens 10G is arranged on the incident side of the light modulator 4G. A field lens 10B is arranged on the incident side of the light modulator 4B. The field lens 10R collimates the light beam of the red light LR incident on the light modulator 4R. The field lens 10G collimates the light beam of the green light LG incident on the light modulator 4G. The field lens 10B collimates the light beam of the blue light LB incident on the light modulator 4B.

[0038] The light synthesizing element 5 synthesizes the image lights corresponding to the red light LR, the green light LG, and the blue light LB by receiving the image lights emitted from the light modulators 4R, 4G, and 4B, and emits the synthesized image lights toward the projection optical device 6. The light synthesizing element 5 uses, for example, a cross dichroic prism.

[0039] The projection optical device 6 is composed of a plurality of projection lenses. The projection optical device 6 enlarges and projects the image light synthesized by the light synthesizing element 5 toward the screen SCR. Thus, a color image is displayed on the screen SCR.

[0040] Next, the structure of the first lighting device 20 will be described.

[0041] Figure 2 It is a side sectional view showing a schematic structure of the first lighting device 20 . Figure 3 yes Figure 2 Cross-sectional view taken along line III-III.

[0042] like Figure 2 As shown, the first illumination device 20 includes a light source device 100 , an integrating optical system 70 , a polarization conversion element 63 , and a superposition optical system 64 .

[0043] The light source device 100 includes a supporting member 30 , a housing 31 , a first light source 41 , a wavelength conversion element 50 , a first light-transmitting member 51 , a first optical layer 52 , a first reflecting member 53 , and a pair of second reflecting members 54 .

[0044] The support member 30 supports the wavelength conversion element 50. The support member 30 functions as a heat dissipation member that diffuses and releases the heat of the wavelength conversion element 50. That is, the wavelength conversion element 50 and the support member 30 are connected in a manner that allows heat transfer. Therefore, the support member 30 is preferably made of a material having a predetermined strength and high thermal conductivity. As the material of the support member 30, for example, a metal such as aluminum or stainless steel is used, and an aluminum alloy such as 6061 series is particularly preferably used.

[0045] According to this configuration, the heat of the wavelength conversion element 50 is released via the support member 30 , so that a temperature increase of the wavelength conversion element 50 can be suppressed.

[0046] like Figure 3 As shown, the support member 30 has a base portion 32 and a support portion 33. The base portion 32 is a plate-shaped member that forms the main body of the support member 30 and has a long side in the X-axis direction. The support portion 33 is provided on a surface 32a of the base portion 32 located on the +Y side. The support portion 33 has a groove 34 that supports the wavelength conversion element 50. The groove 34 extends in the X-axis direction along the long side of the support portion 33 and accommodates the wavelength conversion element 50. The groove 34 of this embodiment has a depth that can accommodate the wavelength conversion element 50 together with the first light-transmitting member 51 and the first optical layer 52. The groove 34 has a bottom surface 34a along the XZ plane and a pair of inner wall surfaces 34b that are separated and arranged in the Z-axis direction and along the XY plane. A pair of second reflecting components 54 described later are respectively arranged on the inner wall surfaces 34b of the groove 34.

[0047] The housing 31 is a member that constitutes the exterior of the light source device 100 together with the support member 30. The housing 31 has a substantially box-like shape with one side open. The housing 31 has a top wall portion 31a, a first side wall portion 31c, a second side wall portion 31d, a third side wall portion 31e, a fourth side wall portion 31f, and a guide port 31k.

[0048] The top wall portion 31 a is arranged along the XZ plane.

[0049] The first side wall portion 31c and the second side wall portion 31d intersect the X-axis along the long side of the wavelength conversion element 50 and are located on opposite sides of each other in the X-axis direction. In the present embodiment, the first side wall portion 31c is located on one side of the X-axis direction, i.e., the -X side, and the second side wall portion 31d is located on the opposite direction of the X-axis direction, i.e., the +X side.

[0050] The third side wall portion 31e and the fourth side wall portion 31f are located on opposite sides of each other in the Z-axis direction intersecting the long side of the wavelength conversion element 50. In the present embodiment, the third side wall portion 31e is located on one side of the Z-axis direction, i.e., the +Z side, and the fourth side wall portion 31f is located on the opposite direction of the Z-axis direction, i.e., the -Z side.

[0051] In this embodiment, the first light source 41 is disposed on the top wall 31a of the housing 31. The first reflective member 53 is disposed on the first side wall 31c of the housing 31. The outlet 31k is provided on the second side wall 31d of the housing 31. The outlet 31k is an opening for guiding light emitted from the first light-transmitting member 51 to the outside.

[0052] In this embodiment, the top wall portion 31a is connected to the first light source 41 in a manner that allows heat transfer. Therefore, the housing 31 is preferably made of a material having a predetermined strength and high thermal conductivity. The material of the housing 31 is the same as that of the support member 30, for example, a metal such as aluminum or stainless steel is used, and an aluminum alloy such as 6061 series is particularly preferably used.

[0053] The housing 31 is arranged so as to cover the support portion 33 of the support member 30 and to abut against the surface 32a of the base portion 32 of the support member 30. That is, the housing 31 covers the first optical layer 52, the first light-transmitting member 51, and the wavelength conversion element 50 supported by the groove 34. In addition, the housing 31 and the support member 30 are fixed to each other by means of fixing members such as adhesives or screws.

[0054] In this way, the light source device 100 of the present embodiment realizes a structure in which the first optical layer 52, the first light-transmitting component 51, the wavelength conversion element 50, and the first light source 41 are stored in the housing 31 and the supporting component 30. Thus, foreign matter such as dust can be prevented from adhering to the first optical layer 52, the first light-transmitting component 51, and the wavelength conversion element 50.

[0055] The first light source 41 includes a plurality of first light emitting elements 41a and a substrate 41b. The plurality of first light emitting elements 41a are mounted on the substrate 41b. In addition, the number of first light emitting elements 41a is not particularly limited, and the first light source 41 may include only one first light emitting element 41a.

[0056] The first light-emitting element 41a emits an excitation light E1 of a first wavelength band. The first light-emitting element 41a is composed of, for example, a light-emitting diode (LED). Each first light-emitting element 41a is opposite to the wavelength conversion element 50, and emits the excitation light E1 toward the wavelength conversion element 50. The first wavelength band is, for example, a wavelength band from blue to violet of 400nm to 480nm, and the peak wavelength is, for example, 445nm. A plurality of first light-emitting elements 41a are arranged along the long side direction of the wavelength conversion element 50. In this way, the first light source 41 of the present embodiment emits an excitation light E composed of a plurality of blue excitation lights E1.

[0057] The wavelength conversion element 50 has a long and narrow plate shape extending along the X-axis and has six faces. The side of the wavelength conversion element 50 extending along the X-axis is longer than the side extending along the Y-axis and the side extending along the Z-axis. The X-axis corresponds to the long side of the wavelength conversion element 50. The Y-axis corresponds to the shortest side of the sides of the wavelength conversion element 50. The length of the side along the Y-axis is shorter than the length of the side along the Z-axis. That is, the cross section of the wavelength conversion element 50 cut along the YZ plane is as follows: Figure 3 A rectangle is shown.

[0058] The wavelength conversion element 50 has a surface 50a and a back surface 50b, a first end surface 50c and a second end surface 50d, and a first side surface 50e and a second side surface 50f. The surface 50a and the back surface 50b intersect the Y-axis and are located on opposite sides of the Y-axis. In the present embodiment, the surface 50a is a surface located on one side of the Y-axis direction along the Y-axis, that is, on the +Y side. The back surface 50b is a surface located on the opposite direction of the Y-axis direction, that is, on the -Y side, and abuts against the bottom surface 34a of the groove 34 of the supporting component 30. That is, the back surface 50b of the wavelength conversion element 50 is a surface connected to the supporting component 30 in a manner that allows heat transfer. The surface 50a is a surface on which the excitation light E is incident via the first optical layer 52 and the first light-transmitting component 51. In the present embodiment, the surface 50a of the wavelength conversion element 50 corresponds to the "first surface" of the claims.

[0059] Alternatively, by forming a reflective film on the back surface 50 b of the wavelength conversion element 50 , the fluorescence Y emitted from the back surface 50 b may be reflected and returned into the wavelength conversion element 50 .

[0060] The first end face 50c and the second end face 50d intersect the front face 50a and the back face 50b, and are located on opposite sides of each other in the X-axis direction along the long side of the wavelength conversion element 50. In the present embodiment, the first end face 50c is located on one side of the X-axis direction, that is, on the -X side, and the second end face 50d is located on the opposite direction of the X-axis, that is, on the +X side.

[0061] The first side surface 50e and the second side surface 50f intersect the front surface 50a and the back surface 50b and the first end surface 50c and the second end surface 50d, and are located on opposite sides of each other in the Z-axis direction. In the present embodiment, the first side surface 50e is located on one side of the Z-axis direction, i.e., the +Z side, and the second side surface 50f is located on the opposite direction of the Z-axis direction, i.e., the -Z side.

[0062] The wavelength conversion element 50 contains at least a yellow phosphor, and converts the excitation light E having a first wavelength band emitted from each light emitting element 41a of the first light source 41 into yellow fluorescence Y having a second wavelength band different from the first wavelength band. In the wavelength conversion element 50, the excitation light E enters from the surface 50a, and the fluorescence Y is emitted from the surface 50a into the first light-transmitting member 51. The excitation light E in this embodiment corresponds to the "first light" in the claims.

[0063] The wavelength conversion element 50 contains a ceramic phosphor composed of a polycrystalline phosphor that converts the wavelength of the excitation light E into the fluorescence Y. The wavelength conversion element 50 contains scatterers such as pores or fillers. Therefore, the wavelength conversion element 50 of this embodiment is composed of a phosphor with light scattering properties. The second wavelength band of the fluorescence Y is, for example, a yellow wavelength band of 490nm to 750nm. That is, the fluorescence Y is a yellow fluorescence containing a red light component and a green light component. The fluorescence Y of this embodiment corresponds to the "second light" in the claims.

[0064] The wavelength conversion element 50 may also contain a single crystal phosphor instead of a polycrystalline phosphor. Alternatively, the wavelength conversion element 50 may also be made of fluorescent glass. Alternatively, the wavelength conversion element 50 may also be made of a material in which a plurality of fluorescent particles are dispersed in a binder made of glass or resin. The wavelength conversion element 50 made of such a material converts the excitation light E into fluorescent light Y.

[0065] Specifically, the material of the wavelength conversion element 50 includes, for example, yttrium aluminum garnet (YAG)-based phosphors. Taking YAG:Ce containing cerium (Ce) as an activator as an example, as the material of the wavelength conversion element 50, a material obtained by mixing raw material powders containing constituent elements such as Y2O3, Al2O3, and CeO3 and subjecting them to a solid phase reaction, Y-Al-O amorphous particles obtained by a wet method such as a coprecipitation method and a sol-gel method, YAG particles obtained by a gas phase method such as a spray drying method, a flame pyrolysis method, and a thermal plasma method, etc. can be used.

[0066] The first light-transmitting member 51 is disposed between the first light source 41 and the wavelength conversion element 50 , and guides the fluorescence Y converted by the wavelength conversion element 50 . Specifically, the first light-transmitting member 51 is provided on the surface 50 a of the wavelength conversion element 50 .

[0067] As a material of the first light-transmitting member 51, for example, borosilicate glass such as BK7, quartz, synthetic quartz, crystal, SiC, GaN, MgO, YAG, sapphire, diamond, etc. are used. The first light-transmitting member 51 of the present embodiment is made of quartz, for example.

[0068] The first light-transmitting component 51 has the same shape as the wavelength conversion element 50. Specifically, the first light-transmitting component 51 has an elongated plate shape extending along the X-axis and has six faces. The first light-transmitting component 51 has a long side in the X-axis direction. The cross section of the first light-transmitting component 51 cut along the YZ plane is as follows: Figure 3 Shown as having a rectangular shape.

[0069] The first light-transmitting component 51 has a surface 51a and a back surface 51b, a first end surface 51c and a second end surface 51d, a first side surface 51e and a second side surface 51f. The surface 51a and the back surface 51b intersect the Y-axis and are located on opposite sides of the Y-axis. In the present embodiment, the surface 51a is located on one side of the Y-axis direction along the Y-axis, that is, the +Y side, and the back surface 51b is located on the opposite direction of the Y-axis direction, that is, the -Y side. The surface 51a is the surface on which the excitation light E is incident through the first optical layer 52 described later. The back surface 51b is the surface opposite to the surface 50a of the wavelength conversion element 50. That is, the back surface 51b of the first light-transmitting component 51 corresponds to the "second surface" of the claims.

[0070] The first end face 51c and the second end face 51d intersect with the front face 51a and the back face 51b, and face opposite sides to each other in the X-axis direction along the long side of the first light-transmitting member 51. In this embodiment, the first end face 51c is located on one side of the X-axis direction, that is, the -X side, and the second end face 51d is located on the opposite direction of the X-axis direction, that is, the +X side. That is, the first end face 51c and the second end face 51d correspond to the "third surface" and the "fourth surface" in the claims.

[0071] The first side surface 51e and the second side surface 51f intersect the surface 51a and the back surface 51b and the first end surface 51c and the second end surface 51d, and face opposite sides in the Z-axis direction. In the present embodiment, the first side surface 51e is located on one side of the Z-axis direction, i.e., the +Z side, and the second side surface 51f is located on the opposite direction of the Z-axis direction, i.e., the -Z side. That is, the first side surface 51e and the second side surface 51f correspond to the "fifth surface" and the "sixth surface" in the claims.

[0072] The first optical layer 52 is disposed between the first light source 41 and the first translucent member 51 and has optical properties of transmitting the excitation light E and reflecting the fluorescence Y. The first optical layer 52 of this embodiment is provided on the surface 51a of the first translucent member 51 and is composed of, for example, a dielectric multilayer film.

[0073] like Figure 2As shown, the first reflecting member 53 is located at the -X side of the X-axis direction of the first light-transmitting member 51 and the wavelength conversion element 50. The first reflecting member 53 is disposed on the first side wall portion 31c of the supporting member 30 in a manner opposite to the first end face 51c of the first light-transmitting member 51 and the first end face 50c of the wavelength conversion element 50. In addition, the first reflecting member 53 may be disposed directly on the first end face 51c of the first light-transmitting member 51 and the first end face 50c of the wavelength conversion element 50 instead of being directly disposed on the first side wall portion 31c.

[0074] The first reflecting member 53 reflects the fluorescence Y that is guided inside the first light-transmitting member 51 and reaches the first end face 51c. In addition, the first reflecting member 53 reflects the excitation light E that is scattered at the surface 50a of the wavelength conversion element 50 and guided inside the first light-transmitting member 51 and reaches the first end face 51c. That is, the first reflecting member 53 reflects the fluorescence Y and the excitation light E. The first reflecting member 53 is composed of, for example, a metal film, a dielectric multilayer film, a scattering member composed of barium sulfate, or the like.

[0075] like Figure 3 As shown, a pair of second reflecting components 54 are located on both sides of the first light-transmitting component 51 and the wavelength conversion element 50 in the Z-axis direction. One of the pair of second reflecting components 54 is provided on the inner wall surface 34b of the groove 34 provided in the support portion 33 in a manner opposite to the first side surface 50e of the wavelength conversion element 50 and the first side surface 51e of the first light-transmitting component 51. The other of the pair of second reflecting components 54 is provided on the inner wall surface 34b of the groove 34 provided in the support portion 33 in a manner opposite to the second side surface 50f of the wavelength conversion element 50 and the second side surface 51f of the first light-transmitting component 51. In addition, the second reflecting component 54 may not be directly provided on the inner wall surface 34b of the groove 34, but may be directly provided on the wavelength conversion element 50 and the first light-transmitting component 51 side.

[0076] The second reflecting member 54 reflects the excitation light E that is scattered on the surface 50a of the wavelength conversion element 50 and enters the first light-transmitting member 51 and reaches the first side surface 51e or the second side surface 51f, and then enters the wavelength conversion element 50. Thus, the conversion efficiency of the excitation light E to the fluorescence Y can be improved. The second reflecting member 54 reflects the fluorescence Y that reaches the first side surface 51e or the second side surface 51f of the first light-transmitting member 51. The second reflecting member 54 reflects the fluorescence Y emitted from the first side surface 50e or the second side surface 50f of the wavelength conversion element 50 toward the wavelength conversion element 50 or the first light-transmitting member 51. The fluorescence Y that returns to the wavelength conversion element 50 is scattered internally and emitted to the first light-transmitting member 51. That is, the second reflecting member 54 reflects the fluorescence Y and the excitation light E. The second reflecting member 54 is composed of, for example, a metal film, a dielectric multilayer film, a scattering member, or the like.

[0077] Next, the operation of light in the light source device 100 of the present embodiment will be described.

[0078] Figure 4 1 and 2 are diagrams for explaining the behavior of light in the light source device 100 .

[0079] like Figure 4 As shown, in the light source device 100 of the present embodiment, the excitation light E emitted from the first light source 41 passes through the first optical layer 52 and the first light-transmitting component 51 and enters the wavelength conversion element 50. In addition, a portion of the excitation light E is backscattered at the surface of the wavelength conversion element 50 and returns to the first light source 41 side, but is reflected by the first optical layer 52 or the first light-transmitting component 51 and enters the wavelength conversion element 50.

[0080] When the excitation light E is incident on the wavelength conversion element 50, the phosphor contained in the wavelength conversion element 50 is excited to emit fluorescence Y from an arbitrary light-emitting point. At this time, the excitation light E incident on the phosphor is diffused and propagates to an area larger than the incident area, thereby generating the so-called fluorescence Y bleeding in which the width of the emission area of ​​the fluorescence Y is expanded.

[0081] The fluorescence Y emitted from the surface 50a of the wavelength conversion element 50 is incident on the first light-transmitting member 51, and is reflected by the first optical layer 52 provided on the surface 51a of the first light-transmitting member 51, and is emitted from the second end surface 51d. That is, in the light source device 100 of the present embodiment, the fluorescence Y propagates inside the first light-transmitting member 51 while repeatedly being scattered by the wavelength conversion element 50 and reflected by the first optical layer 52, and is emitted from the second end surface 51d.

[0082] In this way, the light source device 100 can emit the fluorescence Y generated by the wavelength conversion element 50 to the outside through the outlet 31 k of the housing 31 .

[0083] A portion of the fluorescence Y1 emitted in various directions due to the leakage is emitted into the first light-transmitting member 51 in a manner toward the first end face 51c opposite to the second end face 51d, but is reflected by the first optical layer 52 and is incident on the wavelength conversion element 50 again. The fluorescence Y1 incident on the wavelength conversion element 50 is scattered and converted into various angular components. A portion of the fluorescence Y1 converted into various angular components is reflected by the first optical layer 52 provided on the surface 51a of the first light-transmitting member 51 and is emitted from the second end face 51d.

[0084] In addition, the fluorescence Y that has traveled through the interior of the first light-transmitting member 51 and reached the first end face 51c by being reflected between the first optical layer 52 and the wavelength conversion element 50 is reflected toward the second end face 51d by the first reflecting member 53 and enters the wavelength conversion element 50, and is scattered by the wavelength conversion element 50, and is finally emitted from the second end face 51d. In addition, the excitation light E that has been scattered on the surface 50a of the wavelength conversion element 50 and traveled through the interior of the first light-transmitting member 51 and entered the first end face 51c is reflected by the first reflecting member 53 and enters the wavelength conversion element 50, and is used for conversion of the fluorescence Y in the wavelength conversion element 50.

[0085] In the light source device 100 of this embodiment, most of the fluorescence Y is emitted from the second end face 51d of the first light-transmitting component 51, and the fluorescence Y emitted from the second end face 50d of the wavelength conversion element 50 is very small and is emitted slightly from the vicinity of the surface 50a in the second end face 50d.

[0086] In the light source device 100 of the present embodiment, the fluorescence Y converted by the wavelength conversion element 50 travels inside the first light-transmitting member 51 and is emitted from the second end surface 51 d .

[0087] Figure 5 This is a top view of the light source device 100 viewed from the +X side toward the -X side. Figure 5 1 is a diagram showing a light source device 100 viewed from above in the X-axis direction along the normal direction of the second end surface 51d of the first light-transmitting member 51. Figure 5 The state of looking down along the X-axis direction is referred to as the state of looking down.

[0088] like Figure 5 As shown, the fluorescence Y emitted from the second end surface 51d of the first light-transmitting member 51 is guided to the outside through the guide port 31k provided on the second side wall portion 31d of the housing 31. Figure 5 As shown in FIG. 1 , when viewed from above, the outlet 31k overlaps with the first light-transmitting member 51 and the wavelength conversion element 50. Specifically, the outlet 31k has a size that allows the entire second end face 51d of the first light-transmitting member 51 and the vicinity of the surface 50a in the second end face 50d of the wavelength conversion element 50 to be exposed. That is, the outlet 31k overlaps with the entire second end face 51d of the first light-transmitting member 51 and a portion of the second end face 50d of the wavelength conversion element 50 when viewed from above, and has a minimum size corresponding to the light-emitting area of ​​the fluorescent light Y.

[0089] In this way, the light source device 100 of this embodiment can guide the fluorescence Y emitted from the second end face 51d of the first light-transmitting component 51 and the second end face 50d of the wavelength conversion element 50 to the outside through the minimum guide port 31k. Therefore, the light source device 100 of this embodiment can reduce the loss of light in optical components such as the integrating optical system 70 arranged in the subsequent stage by reducing the optical etendue of the fluorescence Y. As a result, the utilization efficiency of the fluorescence Y of the light source device 100 can be improved.

[0090] In the present embodiment, the first light-transmitting member 51 and the wavelength conversion element 50 are fixed by means of a light-transmitting optical adhesive. Since there is no air layer between the first light-transmitting member 51 and the wavelength conversion element 50, it is possible to suppress the reflection of light at the interface between the first light-transmitting member 51 and the wavelength conversion element 50. The optical adhesive can allow the excitation light E that has passed through the first light-transmitting member 51 to pass through and be incident on the wavelength conversion element 50 efficiently, and can allow the fluorescence Y emitted from the wavelength conversion element 50 to pass through and be incident on the first light-transmitting member 51 efficiently.

[0091] In the present embodiment, the refractive index of the first light-transmitting component 51 (1.4: quartz) is smaller than the refractive index of the wavelength conversion element 50 (YAG: 1.7). The material of the first light-transmitting component 51 that satisfies this relationship is, in addition to quartz, borosilicate glass such as BK7, synthetic quartz, and crystal, etc. According to this structure, when the fluorescence Y is incident on the first light-transmitting component 51 from the wavelength conversion element 50, the fluorescence Y is refracted, so that the angle with the X-axis along the long axis of the first light-transmitting component 51 becomes smaller. That is, the fluorescence Y propagating in the first light-transmitting component 51 is incident at a smaller angle relative to the second end face 51d perpendicular to the X-axis. Therefore, the first light-transmitting component 51 can efficiently extract the fluorescence Y from the second end face 51d.

[0092] In addition, a material having a thermal conductivity greater than that of the wavelength conversion element 50 may be used for the first light-transmitting component 51. Examples of materials of the first light-transmitting component 51 that satisfy this relationship include SiC, GaN, MgO, YAG, sapphire, and diamond. According to this structure, the heat of the wavelength conversion element 50 is efficiently transferred to the first light-transmitting component 51, so that the temperature rise of the wavelength conversion element 50 can be suppressed. Thus, the reduction in luminous efficiency associated with the temperature rise of the wavelength conversion element 50 can be suppressed.

[0093] As described above, the light source device 100 of the present embodiment includes: the first light source 41 that emits the excitation light E in the blue wavelength band; the wavelength conversion element 50 that converts the excitation light E into the fluorescence Y in the yellow wavelength band different from the blue wavelength band; the first light-transmitting member 51 that is disposed between the first light source 41 and the wavelength conversion element 50 and guides the fluorescence Y converted by the wavelength conversion element 50; the first optical layer 52 that is disposed between the first light source 41 and the first light-transmitting member 51 and transmits the excitation light E and reflects the fluorescence Y; and the first reflecting member 53 that reflects the excitation light E and the fluorescence Y. The wavelength conversion element 50 has a surface 50a on which the excitation light E is incident via the first optical layer 52 and the first light-transmitting member 51. The first light-transmitting member 51 has a back surface 51b that is opposite to the surface 50a, and a first end surface 51c and a second end surface 51d that intersect the back surface 51b and face opposite sides to each other. The first end surface 51 c faces the first reflecting member 53 , and the fluorescence Y converted by the wavelength conversion element 50 travels inside the first light-transmitting member 51 and is emitted from the second end surface 51 d .

[0094] According to the light source device 100 of this embodiment, the fluorescence Y reflected by the first optical layer 52 can be scattered at the wavelength conversion element 50, thereby propagating in the first light-transmitting member 51 with the angle distribution changed. Therefore, the fluorescence Y can be incident on the second end surface 51d of the first light-transmitting member 51 at an angle smaller than the critical angle.

[0095] Therefore, according to the light source device 100 of the present embodiment, it is possible to realize a structure for extracting the fluorescence Y more efficiently, compared with a case where the fluorescence Y propagates by total reflection in the first light-transmitting member 51 .

[0096] According to the projector 1 of the present embodiment, since the projector 1 includes the first illumination device 20 including the light source device 100 that efficiently extracts the fluorescent light Y, the light utilization efficiency is excellent.

[0097] (Second Embodiment)

[0098] Next, the structure of the projector of the second embodiment is described. The difference between this embodiment and the first embodiment lies in the structure of the light source device. Therefore, the structure of the light source device is mainly described below. In addition, the same symbols are marked on the structural elements common to the first embodiment, and the description is omitted.

[0099] Figure 6 It is a cross-sectional view showing a schematic structure of a light source device 101 according to the present embodiment.

[0100] like Figure 6As shown, the light source device 101 of this embodiment has a shell 131, a first light source 41, a second light source 42, a wavelength conversion element 50, a first light-transmitting component 51, a second light-transmitting component 151, a first optical layer 52, a second optical layer 152, a first reflecting component 153 and a pair of second reflecting components.

[0101] The housing 131 constitutes the exterior of the light source device 101. The housing 131 is accommodated inside by covering the first light source 41, the second light source 42, the wavelength conversion element 50, the first light-transmitting member 51, and the second light-transmitting member 151. The housing 131 has a box-like shape and has a top wall portion 131a, a bottom wall portion 131b, a first side wall portion 131c, a second side wall portion 131d, a third side wall portion, a fourth side wall portion, and a guide port 131k.

[0102] The top wall 131a is arranged along the XZ plane. The bottom wall 131b is arranged to face the top wall 131a. The first side wall 131c is located on the -X side in the X-axis direction, and the second side wall 31d is located on the +X side in the opposite direction in the X-axis direction.

[0103] The third side wall and the fourth side wall, not shown, are located on opposite sides of each other in the Z-axis direction intersecting the long side of the wavelength conversion element 50. The third side wall is located on the +Z side in the Z-axis direction, and the fourth side wall is located on the -Z side in the opposite direction of the Z-axis direction.

[0104] In this embodiment, the first light source 41 is disposed on the top wall 131a of the housing 131 in a heat transfer manner, and the second light source 42 is disposed on the bottom wall 131b of the housing 131 in a heat transfer manner. The outlet 131k is provided on the second side wall 131d of the housing 131.

[0105] In the present embodiment, the outlet 131k holds the first optical layer 52, the first light-transmitting component 51, the wavelength conversion element 50, the second light-transmitting component 151, and the second optical layer 152. In the present embodiment, when the light source device 101 is viewed from above in the X-axis direction along the normal direction of the second end surface 51d of the first light-transmitting component 51, the outlet 131k overlaps with the first light-transmitting component 51, the wavelength conversion element 50, and the second light-transmitting component 151. Specifically, the outlet 131k has a size that exposes the second end surface 51d of the first light-transmitting component 51, the second end surface 50d of the wavelength conversion element 50, and the second end surface 151d of the second light-transmitting component 151.

[0106] In addition, in the X-axis direction, the opening end of the outlet 131 k is coplanar with the second end face 51 d of the first light-transmitting component 51 , the second end face 50 d of the wavelength conversion element 50 , and the second end face 151 d of the second light-transmitting component 151 .

[0107] The second light source 42 is arranged on the opposite side of the first light source 41, that is, on the -Y side, with respect to the wavelength conversion element 50, and emits excitation light E. The second light source 42 has the same structure as the first light source 41. Therefore, the second light source 42 has a substrate 42b and a plurality of second light emitting elements 42a that emit excitation light in the first wavelength band.

[0108] The second light-transmitting member 151 is disposed between the second light source 42 and the wavelength conversion element 50, and guides the fluorescence Y converted by the wavelength conversion element 50. Specifically, the second light-transmitting member 151 is provided on the back surface 50b of the wavelength conversion element 50. The second light-transmitting member 151 has the same structure as the first light-transmitting member 51.

[0109] Therefore, the second light-transmitting member 151 has an elongated plate shape extending along the X axis and has six faces. The second light-transmitting member 151 has a front face 151a and a back face 151b, a first end face 151c and a second end face 151d, and a first side face and a second side face.

[0110] The second optical layer 152 is disposed between the second light source 42 and the second translucent member 151 and has optical properties of transmitting the excitation light E and reflecting the fluorescence Y. The second optical layer 152 of this embodiment is provided on a surface 151 a of the second translucent member 151 described later and is composed of, for example, a dielectric multilayer film.

[0111] In this embodiment, the excitation light E emitted from the second light source 42 enters the back surface 50b of the wavelength conversion element 50 via the second optical layer 152 and the second light-transmitting member 151. That is, the back surface 50b of the wavelength conversion element 50 corresponds to the "seventh surface" of the claims.

[0112] In the second light-transmitting component 151 of the present embodiment, the surface 151a is located on one side of the Y-axis direction along the Y-axis, that is, the -Y side, and the back surface 151b is located on the opposite direction of the Y-axis direction, that is, the +Y side. The surface 151a is the surface on which the excitation light E is incident via the second optical layer 152. The back surface 151b is the surface opposite to the back surface 50b of the wavelength conversion element 50. That is, the back surface 151b of the second light-transmitting component 151 corresponds to the "eighth surface" of the claims.

[0113] In this embodiment, the first end face 151c and the second end face 151d face opposite to each other in the X-axis direction that intersects the surface 151a and the back surface 151b and is along the long side of the second light-transmitting member 151. In this embodiment, the first end face 151c is located on one side of the X-axis direction, i.e., the -X side, and the second end face 151d is located on the opposite direction of the X-axis direction, i.e., the +X side. That is, the first end face 151c and the second end face 151d correspond to the "ninth surface" and the "tenth surface" of the claims.

[0114] The first reflecting member 153 is located at the -X side in the X-axis direction of the first light-transmitting member 51, the second light-transmitting member 151, and the wavelength conversion element 50. The first reflecting member 153 is provided on the first side wall portion 131c of the housing 131 so as to be opposed to the first end face 51c of the first light-transmitting member 51, the first end face 151c of the second light-transmitting member 151, and the first end face 50c of the wavelength conversion element 50.

[0115] Although not shown in the figure, in the present embodiment, a pair of second reflective components are located on both sides of the first light-transmitting component 51, the second light-transmitting component 151, and the wavelength conversion element 50 in the Z-axis direction. One second reflective component is provided on the third side wall portion of the housing 131 in a manner opposite to the first side surface 50e of the wavelength conversion element 50, the first side surface 51e of the first light-transmitting component 51, and the first side surface of the second light-transmitting component 151. The other second reflective component is provided on the fourth side wall portion of the housing 131 in a manner opposite to the second side surface 50f of the wavelength conversion element 50, the second side surface 51f of the first light-transmitting component 51, and the second side surface of the second light-transmitting component 151.

[0116] Next, the operation of light in the light source device 101 of this embodiment is described. Since the fluorescence Y generated by the excitation light E of the first light source 41 and the fluorescence Y generated by the excitation light E of the second light source 42 show the same operation, the excitation light E emitted from the first light source 41 is used as an example for description.

[0117] In the light source device 101 of this embodiment, the fluorescence Y2 emitted from the wavelength conversion element 50 enters the first light-transmitting member 51, is reflected by the first optical layer 52 provided on the surface 51a of the first light-transmitting member 51, and is emitted from the second end surface 51d.

[0118] The fluorescence Y3 emitted in the normal direction from the surface 50a of the wavelength conversion element 50 passes through the first light-transmitting member 51 and is reflected by the first optical layer 52, thereby returning to the wavelength conversion element 50. The fluorescence Y3 is incident on the first light-transmitting member 51 in a state of being scattered by the wavelength conversion element 50 and having its angle converted, and is reflected by the first optical layer 52 and emitted from the second end surface 51d.

[0119] A portion of the fluorescence Y4 passes through the second light-transmitting member 151, is reflected by the second optical layer 152, and is emitted from the second end face 151d. The fluorescence Y that is reflected between the second optical layer 152 and the wavelength conversion element 50, travels inside the second light-transmitting member 151, and reaches the first end face 151c is reflected by the first reflecting member 153 toward the second end face 151d and enters the wavelength conversion element 50, undergoes angle conversion, and is finally emitted from the second end face 151d.

[0120] In the present embodiment, the fluorescence Y reflected between the first optical layer 52 and the wavelength conversion element 50, travels inside the first light-transmitting component 51, and reaches the first end surface 51c, is reflected toward the second end surface 51d by the first reflecting component 153, enters the wavelength conversion element 50, is scattered by the wavelength conversion element 50, and finally exits from the second end surface 51d. In addition, the excitation light E scattered at the surface 50a of the wavelength conversion element 50, travels inside the first light-transmitting component 51, and enters the first end surface 51c is reflected by the first reflecting component 153, enters the wavelength conversion element 50, and is used for conversion of the fluorescence Y in the wavelength conversion element 50.

[0121] According to the light source device 101 of the present embodiment, by making the excitation light E incident from both the surface 50a and the back surface 50b of the wavelength conversion element 50, the incident amount of the excitation light E can be increased. Here, as the length of the wavelength conversion element 50 in the X-axis direction increases, it is difficult to extract the fluorescence Y generated on the opposite side of the lead-out port. Therefore, in the case where the incident area of ​​the excitation light E is enlarged by increasing the length of the wavelength conversion element 50 in the X-axis direction, the fluorescence Y may not be efficiently extracted. In contrast, in the light source device 101 of the present embodiment, by increasing the incident light amount of the excitation light E without increasing the length of the wavelength conversion element 50 in the X-axis direction, the generated fluorescence can be efficiently extracted while improving the fluorescence conversion efficiency.

[0122] In addition, in the light source device 100 of the first embodiment, the reflective film formed on the back side 50b of the wavelength conversion element 50 is used to return the fluorescence Y into the wavelength conversion element 50, but the reflective film formed on the back side 50b having projections and depressions is difficult to obtain sufficient film performance, and thus light absorption is easily generated.

[0123] In contrast, in the present embodiment, the fluorescence Y emitted from the back surface 50b of the wavelength conversion element 50 is reflected between the second optical layer 152 composed of a dielectric multilayer film and the wavelength conversion element 50 and propagates in the second light-transmitting member 151, so that the fluorescence Y can be efficiently extracted. In addition, the second optical layer 152 is formed on the surface 151a of the second light-transmitting member 151 composed of a smooth surface, so the film performance is high and the fluorescence Y can be reflected efficiently.

[0124] (Third Embodiment)

[0125] Next, the structure of the projector of the third embodiment is described. The difference between this embodiment and the second embodiment lies in the structure of the light source device. Therefore, the structure of the light source device is mainly described below. In addition, the same symbols are marked on the structural elements common to the first embodiment, and the description is omitted.

[0126] Figure 7 It is a cross-sectional view showing a schematic structure of the light source device 102 according to the present embodiment.

[0127] The light source device 102 of this embodiment is different from the light source device 101 of the second embodiment in the structure of the wavelength conversion element, and other than that, they are the same. Therefore, the following mainly describes the different light behaviors based on the wavelength conversion element.

[0128] like Figure 7 As shown, the light source device 102 of this embodiment has a shell 131, a first light source 41, a second light source 42, a wavelength conversion element 150, a first light-transmitting component 51, a second light-transmitting component 151, a first optical layer 52, a second optical layer 152, a first reflecting component 153 and a pair of second reflecting components.

[0129] The wavelength conversion element 150 of this embodiment is composed of a transparent phosphor. Here, the transparent phosphor refers to, for example, a phosphor having a total transmittance of 80% or more for fluorescence. As a transparent phosphor, as described above, there are transparent single crystals or polycrystalline bodies having a total transmittance of 80% or more, for example, a YAG ceramic-based ceramic phosphor formed by sintering a plurality of YAG phosphor particles. The wavelength conversion element 150 converts the wavelength of the excitation light E incident from the first light source 41 and the second light source 42 to generate fluorescence Y.

[0130] The wavelength conversion element 150 of the present embodiment has a front surface 150 a and a rear surface 150 b , a first end surface 150 c and a second end surface 150 d , and a first side surface and a second side surface (not shown), similarly to the wavelength conversion element 50 .

[0131] Next, the operation of light in the light source device 102 of the present embodiment will be described. Hereinafter, the excitation light E emitted from the first light source 41 will be described as an example.

[0132] In the light source device 102 of this embodiment, the fluorescence Y5 emitted from the wavelength conversion element 150 is totally reflected at the interface between the wavelength conversion element 150 and the first light-transmitting component 51 or the second light-transmitting component 151, thereby propagating within the wavelength conversion element 150 and being emitted from the second end face 150d of the wavelength conversion element 150.

[0133] The fluorescence Y6 incident on the first light-transmitting component 51 at an angle larger than the critical angle is reflected by the first optical layer 52 and returns to the wavelength conversion element 150, passes through the wavelength conversion element 150, is incident on the second light-transmitting component 151, and is emitted from the second end surface 151d of the second light-transmitting component 151. In addition, the fluorescence Y7 incident on the second light-transmitting component 151 is reflected by the second optical layer 152 and is emitted from the second end surface 151d of the second light-transmitting component 151. A part of the fluorescence passes through the wavelength conversion element 50 from the second light-transmitting component 151, propagates in the first light-transmitting component 51, and is emitted from the second end surface 51d.

[0134] In addition, the refractive index of the first light-transmitting component 51 and the second light-transmitting component 151 is closer to the refractive index of air than the refractive index of the wavelength conversion element 150. In the light source device 102 of this embodiment, the second end face 51d of the first light-transmitting component 51 and the second end face 151d of the second light-transmitting component 151 emit more light than the second end face 150d of the wavelength conversion element 150.

[0135] A portion of the fluorescence Y8 passes through the first light-transmitting component 51, is reflected by the first optical layer 52, and is incident on the second end face 150d of the wavelength conversion element 150. The fluorescence Y8 is totally reflected by the second end face 150d and is incident on the second light-transmitting component 151, is reflected by the second optical layer 152, and is incident on the wavelength conversion element 150 again. The fluorescence Y8 that has returned to the wavelength conversion element 150 is scattered by the wavelength conversion element 150 and is angle-converted, and is finally emitted from the second end face 51d of the first light-transmitting component 51 or the second end face 151d of the second light-transmitting component 151.

[0136] According to the light source device 102 of this embodiment, when using a wavelength conversion element 150 composed of a transparent phosphor, similar to the light source device 101 of the second embodiment, by increasing the incident light amount of the excitation light E without increasing the length of the wavelength conversion element 150 in the X-axis direction, the generated fluorescence Y can be efficiently derived while improving the fluorescence conversion efficiency.

[0137] (Fourth Embodiment)

[0138] Next, the structure of the projector of the fourth embodiment is described. The difference between this embodiment and the first embodiment lies in the structure of the light source device. Therefore, the structure of the light source device is mainly described below. In addition, the same symbols are marked on the structural elements common to the first embodiment, and the description is omitted.

[0139] Figure 8 It is a cross-sectional view showing a schematic structure of the light source device 103 according to the present embodiment.

[0140] like Figure 8As shown, the light source device 103 of this embodiment includes a supporting member 30, a housing 31, a first light source 141, a wavelength conversion element 250, a first light-transmitting member 51, a first optical layer 252, a first reflecting member 53, and a pair of second reflecting members.

[0141] The first light source 141 of this embodiment includes a plurality of first light emitting elements 141a and a substrate 141b. The plurality of first light emitting elements 141a are mounted on the substrate 141b. In addition, the number of first light emitting elements 141a is not particularly limited, and the first light source 141 may include only one first light emitting element 141a.

[0142] The first light-emitting element 141a of the present embodiment emits excitation light of the first wavelength band. The first light-emitting element 141a is composed of, for example, a light-emitting diode (LED). Each first light-emitting element 141a is opposite to the wavelength conversion element 250, and emits excitation light toward the wavelength conversion element 250. The first wavelength band is, for example, a wavelength band in the ultraviolet region of 100nm to 400nm, and the peak wavelength is 380nm. A plurality of first light-emitting elements 141a are arranged along the long side direction of the wavelength conversion element 250. In this way, the first light source 141 of the present embodiment emits ultraviolet light Ur composed of a plurality of excitation light rays.

[0143] The wavelength conversion element 250 of the present embodiment has a long and narrow plate shape extending along the X-axis and has six surfaces, similarly to the wavelength conversion element 50 of the first embodiment.

[0144] The wavelength conversion element 250 of this embodiment is composed of a blue phosphor that converts the ultraviolet light Ur emitted from the first light source 141 into blue fluorescence BY having a second wavelength band different from the first wavelength band, for example, a blue wavelength band of 450nm to 495nm. As the blue phosphor, for example, BaMgAl 10 O 17 :Eu(II), etc. The ultraviolet light Ur in this embodiment corresponds to the "first light" in the claims, and the fluorescent light BY corresponds to the "second light" in the claims.

[0145] The first optical layer 252 is disposed between the first light source 141 and the first light-transmitting member 51 , and has an optical property of transmitting ultraviolet rays Ur and reflecting fluorescent light BY.

[0146] The other structures are the same as those of the light source device 100 according to the first embodiment, and thus the description thereof is omitted.

[0147] In the light source device 103 of the present embodiment, the fluorescence BY propagates inside the first light-transmitting member 51 while repeating scattering by the wavelength conversion element 250 and reflection by the first optical layer 252 , and is emitted from the second end surface 51 d .

[0148] In this way, the light source device 103 can emit the fluorescence BY generated by the wavelength conversion element 250 to the outside through the outlet 31 k of the housing 31 .

[0149] In the light source device 103 of the present embodiment, the fluorescence BY reflected by the first optical layer 252 can also be scattered at the wavelength conversion element 250, so as to propagate in the first light-transmitting member 51 with the angle distribution changed. Therefore, the fluorescence BY can be incident on the second end surface 51d of the first light-transmitting member 51 at an angle smaller than the critical angle.

[0150] Therefore, according to the light source device 103 of the present embodiment, it is possible to realize a structure for efficiently extracting the fluorescence BY, compared with a case where the fluorescence BY propagates by total reflection in the first light-transmitting member 51 .

[0151] Furthermore, the light source device 103 of this embodiment includes the first light source 41 using the first light emitting element 141a formed of an LED. Therefore, compared with a light source device using a plurality of blue semiconductor lasers, less heat is generated and the structure of the cooling device can be miniaturized.

[0152] In addition, when using a conventional laser light source, in order to achieve an increase in the amount of blue light, a light synthesis optical system such as a reflector and a prism is required, so there is a problem that the device structure is easily enlarged. In contrast, when the light source device 103 of this embodiment achieves an increase in the amount of blue light, it can also be dealt with by extending the length of the wavelength conversion element 250 and increasing the number of the first light-emitting elements 141a, so it also has the advantage of being able to suppress the enlargement of the device structure.

[0153] 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 gist of the present invention. In addition, one aspect of the present invention can be configured by appropriately combining the characteristic portions of the above-described embodiments.

[0154] In addition, the specific description of the shape, quantity, configuration, material, etc. of each component of the light source device and the projector is not limited to the above-mentioned embodiment and can be appropriately changed. In addition, in the above-mentioned embodiment, an example of mounting the light source device of the present invention on a projector using a liquid crystal panel is shown, but it is not limited to this. The light source device of the present invention can also be applied to a projector using a digital micromirror device as a light modulator. In addition, the projector may not have multiple light modulators, but may only have one light modulator.

[0155] Furthermore, the light source device of the present invention can also be applied to lighting equipment, automobile headlights, and the like.

[0156] (Summary of this disclosure)

[0157] The following is a summary of the present disclosure.

[0158] (Note 1)

[0159] A light source device, characterized in that the light source device comprises: a first light source, which emits first light of a first wavelength band; a wavelength conversion element, which converts the first light into second light of a second wavelength band different from the first wavelength band; a first translucent component, which is arranged between the first light source and the wavelength conversion element, and guides the second light converted by the wavelength conversion element; a first optical layer, which is arranged between the first light source and the first translucent component, and allows the first light to pass through and reflects the second light; and a first reflecting component, which reflects the first light and the second light, the wavelength conversion element having a first surface for the first light to be incident via the first optical layer and the first translucent component, the first translucent component having: a second surface, which is opposite to the first surface; and a third surface and a fourth surface, which intersect with the second surface and face opposite sides to each other, the third surface is opposite to the first reflecting component, and the second light converted by the wavelength conversion element travels inside the first translucent component and is emitted from the fourth surface.

[0160] According to the light source device of the structure of Supplement 1, the second light reflected from the first optical layer can be scattered at the wavelength conversion element, thereby propagating in the first light-transmitting component while changing the angle distribution. Therefore, the second light can be incident on the fourth surface of the first light-transmitting component at an angle smaller than the critical angle. Therefore, according to the light source device of this structure, compared with the case where the second light is propagated in the first light-transmitting component by total reflection, it is possible to efficiently extract the second light.

[0161] (Note 2)

[0162] The light source device according to Supplementary Note 1 is characterized in that the refractive index of the first light-transmitting member is smaller than the refractive index of the wavelength conversion element.

[0163] According to the structure of Supplementary Note 2, when the second light is incident on the first light-transmitting component from the wavelength conversion element, the second light is refracted, so that the angle formed with the long axis of the first light-transmitting component becomes smaller. That is, the second light propagating in the first light-transmitting component is incident on the fourth surface orthogonal to the long axis at a small angle. Therefore, the first light-transmitting component can efficiently extract the second light from the fourth surface.

[0164] (Note 3)

[0165] The light source device according to Supplementary Note 1 or 2 is characterized in that the thermal conductivity of the first light-transmitting component is greater than the thermal conductivity of the wavelength conversion element.

[0166] According to the configuration of Supplementary Note 3, the heat of the wavelength conversion element is efficiently transferred to the first light-transmitting member, so that the temperature rise of the wavelength conversion element can be suppressed. Thus, the reduction in luminous efficiency associated with the temperature rise of the wavelength conversion element can be suppressed.

[0167] (Note 4)

[0168] The light source device according to any one of Supplementary Notes 1 to 3 is characterized in that the first light-transmitting member and the wavelength conversion element are fixed together by means of a light-transmitting adhesive.

[0169] According to the structure of Supplementary Note 4, the optical adhesive can be used to allow the first light that has passed through the first light-transmitting member to pass through and efficiently enter the wavelength conversion element, and the second light emitted from the wavelength conversion element to pass through and efficiently enter the first light-transmitting member.

[0170] (Note 5)

[0171] The light source device according to any one of Notes 1 to 4 is characterized in that the light source device also has a second reflecting component that reflects the first light and the second light, and the first light-transmitting component also has a fifth surface and a sixth surface, which respectively intersect the second surface, the third surface and the fourth surface and face opposite sides to each other, and the second reflecting component is arranged opposite to the fifth surface and the sixth surface.

[0172] According to the configuration of Supplementary Note 5, the second reflecting member reflects the first light, thereby improving the efficiency of converting the first light into the second light. Also, the second reflecting member reflects the second light, thereby improving the efficiency of extracting the second light.

[0173] (Note 6)

[0174] The light source device according to any one of Notes 1 to 5 is characterized in that the light source device also has a supporting component that supports the wavelength conversion element, the wavelength conversion element has a seventh surface facing the side opposite to the first surface, and the seventh surface is connected to the supporting component in a manner that allows heat transfer.

[0175] According to the configuration of Supplementary Note 6, the heat of the wavelength conversion element is released via the support member, so that the temperature rise of the wavelength conversion element can be suppressed. Therefore, the conversion efficiency of the second light of the wavelength conversion element can be improved.

[0176] (Note 7)

[0177] The light source device according to any one of Notes 1 to 6 is characterized in that the light source device also has a shell, which covers the first optical layer, the first light-transmitting component and the wavelength conversion element, and the shell has an outlet for exporting the second light emitted from the fourth surface of the first light-transmitting component to the outside, and when viewed from above along the normal direction of the fourth surface, the outlet overlaps with the first light-transmitting component and the wavelength conversion element.

[0178] According to the structure of Supplementary Note 7, by providing the housing, it is possible to suppress foreign matter such as dust from being attached to the first optical layer, the first light-transmitting member, and the wavelength conversion element. In addition, the second light can be efficiently guided out to the outside through the guide port.

[0179] (Note 8)

[0180] The light source device according to any one of Notes 1 to 7 is characterized in that the light source device also has: a second light source, which is arranged on the side opposite to the first light source relative to the wavelength conversion element and emits the first light; and a second translucent component, which is arranged between the second light source and the wavelength conversion element and guides the second light converted by the wavelength conversion element; and a second optical layer, which is arranged between the second light source and the second translucent component and allows the first light to pass through and reflects the second light, the wavelength conversion element has a seventh surface facing the side opposite to the first surface, and the first light emitted from the second light source is incident on the seventh surface via the second optical layer and the second translucent component, and the second translucent component has: an eighth surface opposite to the seventh surface; and a ninth surface and a tenth surface, which intersect with the eighth surface and face opposite sides to each other, the ninth surface is opposite to the first reflecting component, and the second light converted by the wavelength conversion element travels inside the second translucent component and is emitted from the tenth surface.

[0181] According to the structure of Supplementary Note 8, the incident amount of the first light can be increased by causing the first light to enter from both sides of the first surface and the seventh surface of the wavelength conversion element. Here, as the length of the wavelength conversion element increases, it is difficult to extract the second light generated opposite to the extraction side. Therefore, for example, when the incident area of ​​the first light is enlarged by increasing the length of the wavelength conversion element, the second light may not be efficiently extracted. In contrast, in this structure, by increasing the incident light amount of the first light without increasing the length of the wavelength conversion element, the generated second light can be efficiently extracted while improving the conversion efficiency of the second light.

[0182] (Note 9)

[0183] The light source device according to Note 8 is characterized in that the light source device also has a shell, which accommodates the first optical layer, the second optical layer, the first light-transmitting component, the second light-transmitting component and the wavelength conversion element, and the shell has an outlet for guiding out the second light emitted from the fourth surface and the tenth surface, and when viewed from above along the normal direction of the fourth surface, the outlet overlaps with the first light-transmitting component, the wavelength conversion element and the second light-transmitting component.

[0184] According to the structure of Supplementary Note 9, by having a housing, foreign matter such as dust can be prevented from adhering to the first optical layer, the second optical layer, the first light-transmitting member, the second light-transmitting member, and the wavelength conversion element. In addition, the second light can be efficiently guided to the outside through the guide port.

[0185] (Note 10)

[0186] The light source device according to any one of Supplementary Notes 1 to 9, characterized in that the wavelength conversion element is composed of a transparent fluorescent body.

[0187] According to the structure of Note 10, even when a wavelength conversion element composed of a transparent fluorescent material is used, by increasing the incident light amount of the first light without increasing the length of the wavelength conversion element, the generated second light can be efficiently extracted while improving the conversion efficiency of the second light.

[0188] (Note 11)

[0189] The light source device according to any one of Supplementary Notes 1 to 9, characterized in that the wavelength conversion element is composed of a fluorescent material having a light scattering property.

[0190] According to the structure of Appendix 11, by using a wavelength conversion element composed of a scattering fluorescent body, the second light can be efficiently emitted from the fourth surface while propagating inside the first light-transmitting member while repeating scattering based on the wavelength conversion element and reflection based on the first optical layer.

[0191] (Note 12)

[0192] The light source device according to Note 11 is characterized in that the wavelength conversion element is a yellow phosphor, the first light is blue light, the second light is yellow fluorescence, and the fluorescence propagates inside the first light-transmitting component while repeatedly undergoing scattering based on the wavelength conversion element and reflection based on the first optical layer and is emitted from the fourth surface.

[0193] According to the structure of Supplementary Note 12, the yellow fluorescence generated by the wavelength conversion element can be efficiently extracted from the fourth surface.

[0194] (Note 13)

[0195] The light source device according to Note 11 is characterized in that the wavelength conversion element is a blue phosphor, the first light is ultraviolet light, and the second light is blue fluorescence, and the fluorescence propagates inside the first light-transmitting component while repeatedly undergoing scattering based on the wavelength conversion element and reflection based on the first optical layer and is emitted from the fourth surface.

[0196] According to the structure of Supplementary Note 13, the blue fluorescence generated by the wavelength conversion element can be efficiently extracted from the fourth surface.

[0197] (Note 14)

[0198] A projector, characterized in that the projector has: a light source device as described in any one of Notes 1 to 13; a light modulation device that modulates light from the light source device; and a projection optical device that projects the light modulated by the light modulation device.

[0199] According to the projector having the structure of Supplementary Note 14, since the projector includes a light source device that efficiently extracts light, it is possible to provide a projector that is excellent in light utilization efficiency.

Claims

1. A light source device, characterized in that: have: A first light source emitting a first light of a first wavelength band; a wavelength conversion element, which converts the first light into second light in a second wavelength band different from the first wavelength band; A first light-transmitting member is disposed between the first light source and the wavelength conversion element and guides the second light converted by the wavelength conversion element; A first optical layer is disposed between the first light source and the first light-transmitting member, and transmits the first light and reflects the second light; as well as a first reflecting member that reflects the first light and the second light, The wavelength conversion element has a first surface on which the first light is incident via the first optical layer and the first light-transmitting member. The first light-transmitting member has: a second surface facing the first surface; and a third surface and a fourth surface intersecting the second surface and facing opposite sides to each other. The third surface is opposite to the first reflecting component, The second light converted by the wavelength conversion element travels inside the first light-transmitting member and is emitted from the fourth surface.

2. The light source device according to claim 1, characterized in that: The refractive index of the first light-transmitting component is smaller than the refractive index of the wavelength conversion element.

3. The light source device according to claim 1, characterized in that: The thermal conductivity of the first light-transmitting component is greater than the thermal conductivity of the wavelength conversion element.

4. The light source device according to claim 1, characterized in that: The first light-transmitting member and the wavelength conversion element are fixed together by means of a light-transmitting adhesive.

5. The light source device according to claim 1, characterized in that: The light source device further includes a second reflecting member that reflects the first light and the second light. The first light-transmitting component further has a fifth surface and a sixth surface, which intersect the second surface, the third surface and the fourth surface respectively and face opposite sides to each other. The second reflecting member is arranged to face the fifth surface and the sixth surface.

6. The light source device according to any one of claims 1 to 5, characterized in that: The light source device further includes a supporting member for supporting the wavelength conversion element. The wavelength conversion element has a seventh surface facing a side opposite to the first surface, The seventh surface is connected to the support member in a heat-transferable manner.

7. The light source device according to any one of claims 1 to 5, characterized in that: The light source device further includes a housing that covers the first optical layer, the first light-transmitting member, and the wavelength conversion element. The housing has a guide port for guiding the second light emitted from the fourth surface of the first light-transmitting member to the outside. The guide outlet overlaps with the first light-transmitting member and the wavelength conversion element when viewed in plan along the normal direction of the fourth surface.

8. The light source device according to any one of claims 1 to 5, characterized in that: The light source device further comprises: a second light source, which is arranged on a side opposite to the first light source with respect to the wavelength conversion element and emits the first light; as well as A second light-transmitting member is disposed between the second light source and the wavelength conversion element, and guides the second light converted by the wavelength conversion element; as well as a second optical layer disposed between the second light source and the second light-transmitting member, transmitting the first light and reflecting the second light; The wavelength conversion element has a seventh surface facing the side opposite to the first surface, and the first light emitted from the second light source is incident on the seventh surface via the second optical layer and the second light-transmitting member. The second light-transmitting member has: an eighth surface, which is opposite to the seventh surface; and a ninth face and a tenth face, which intersect the eighth face and face opposite to each other, The ninth surface is opposite to the first reflecting component, The second light converted by the wavelength conversion element travels inside the second light-transmitting member and is emitted from the tenth surface.

9. The light source device according to claim 8, characterized in that: The light source device further comprises a housing, the housing accommodating the first optical layer, the second optical layer, the first light-transmitting component, the second light-transmitting component and the wavelength conversion element. The housing has an outlet for guiding out the second light emitted from the fourth surface and the tenth surface. When viewed in plan along the normal direction of the fourth surface, the guide outlet overlaps with the first light-transmitting member, the wavelength conversion element, and the second light-transmitting member.

10. The light source device according to any one of claims 1 to 5, characterized in that: The wavelength conversion element is composed of a transparent fluorescent substance.

11. The light source device according to any one of claims 1 to 5, characterized in that: The wavelength conversion element is composed of a fluorescent material having light scattering properties.

12. The light source device according to claim 11, characterized in that: The wavelength conversion element is a yellow phosphor, The first light is blue light, The second light is yellow fluorescence, The fluorescence propagates inside the first light-transmitting member while repeating scattering by the wavelength conversion element and reflection by the first optical layer, and is emitted from the fourth surface.

13. The light source device according to claim 11, characterized in that: The wavelength conversion element is a blue phosphor, The first light is ultraviolet light, The second light is blue fluorescence, The fluorescence propagates inside the first light-transmitting member while repeating scattering by the wavelength conversion element and reflection by the first optical layer, and is emitted from the fourth surface.

14. A projector, characterized in that: have: The light source device according to any one of claims 1 to 5; a light modulation device for modulating light from the light source device; as well as A projection optical device projects the light modulated by the light modulation device.

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