Light source and projector

Abstract

To provide a light source device that has a less loss of output light.SOLUTION: A light source device of the present invention comprises: a light emitting element; a light guiding member; an angle conversion member; a support member; and a pressing member. Light to be guided through the light guiding member is emitted toward an incidence end surface from a first plane. Light to be emitted from the light emitting element is incident upon the light guiding member from a lateral surface. The angle conversion member is fixed to the support member. An end part including a second surface of the light guiding member is not fixed to the support member. A linear expansion coefficient is greater than that of the light guiding member. Let an area including the first surface of the light guiding member be a first area, and let an area including the second surface be a second area, the pressing member has; a first pressure part that presses the light guiding member from the lateral surface in the first surface; and a second pressure part that presses the lateral surface of the light guiding member in the second area, in which pressure force pressing the light guiding member of the first pressure part is greater than that pressing the light guiding member of the second pressure part.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] As a light source device for use in a projector, a light source device that utilizes fluorescence emitted from a phosphor when the phosphor is irradiated with excitation light emitted from a light-emitting element has been proposed. The following Patent Document 1 discloses a light source device that includes a light source, a light emitter that converts the wavelength of the light emitted from the light source, a collimator that collimates the light emitted from the light emitter, a holding member that holds the light emitter, and a pressing member that presses the light emitter toward the holding member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 254455 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses a light source device having two pressing members arranged at an interval in the longitudinal direction of a light emitter, each pressing the light emitter. It also discloses that the two pressing members press the light emitter with different forces. However, it does not disclose how to make the forces of the two pressing members different.

[0005] In this type of light source device, the light emitter and the collimator are joined by a joining material such as an adhesive, but the joining strength is limited because the joining area is small. Therefore, for example, if stress occurs on the joining surface between the light emitter and the collimator due to thermal expansion of the light emitter, the collimator may peel off from the light emitter. If the collimator peels off from the light emitter, the light source device cannot obtain the desired light output.

[0006] Although the above description has been given taking a light source device with wavelength conversion as an example, a light source device without wavelength conversion has the same problem. It is desired to provide a light source device that can emit light with a desired intensity with little loss of output light. [Means for solving the problem]

[0007] In order to solve the above problem, a light source device according to one aspect of the present invention includes a light emitting element that emits light, a light guiding member that guides the light emitted from the light emitting element, an angle conversion member that converts the angular distribution of the light emitted from the light guiding member, a support member that supports the light guiding member, and a pressing member that presses the light guiding member against the support member. The light guiding member has a first surface and a second surface that are located opposite to each other in the longitudinal direction of the light guiding member, and a side surface that contacts each of the first surface and the second surface. The angle conversion member has an incident end surface into which the light emitted from the light guiding member is incident, and an exit end surface that exits the light incident from the incident end surface. The light that is guided through the light guiding member is emitted from the first surface toward the incident end surface. The light emitted from the light emitting element is incident on the light guiding member from the side surface. The angle conversion member is fixed to the support member. Among the longitudinal ends of the light guiding member, an end including the second surface is not fixed to the support member. The linear expansion coefficient of the support member is greater than that of the light guiding member. When a virtual cross section dividing the light guiding member into two equal parts in the longitudinal direction is taken as a boundary, a region including the first surface of the light guiding member is taken as a first region, and a region including the second surface of the light guiding member is taken as a second region, the pressing member has a first pressing portion that presses the light guiding member from the side surface in the first region and a second pressing portion that presses the light guiding member from the side surface in the second region, and a pressing force with which the first pressing portion presses the light guiding member is greater than a pressing force with which the second pressing portion presses the light guiding member.

[0008] A projector of one embodiment of the present invention comprises a light source device of one embodiment of the present invention, a light modulation device that modulates light emitted from the light source device in accordance with image information, and a projection optical device that projects the light modulated by the light modulation device. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic configuration diagram of a projector according to a first embodiment. [Diagram 2] FIG. 2 is a schematic configuration diagram of a first illumination device according to the first embodiment. [Diagram 3] FIG. 1 is a perspective view of a light source device according to a first embodiment. [Figure 4] FIG. 2 is a plan view of the light source device. [Diagram 5] 4 is a cross-sectional view of the light source device taken along line VV in FIG. [Figure 6] 5A to 5C are schematic diagrams showing the magnitude relationship between the pressing forces of two pressing members in the light source device of the first embodiment. [Figure 7] 5A and 5B are schematic diagrams showing the magnitude relationship between the pressing forces of two pressing members in a light source device of a comparative example. [Figure 8] FIG. 11 is a cross-sectional view of a light source device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [First embodiment] Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. The projector of this embodiment is an example of a projector that uses a liquid crystal panel as a light modulation device. In the drawings, the dimensions of the components may be shown on different scales in order to make the components easier to see.

[0011] FIG. 1 is a schematic configuration diagram of a projector 1 of the present embodiment. As shown in Fig. 1, the projector 1 of this embodiment is a projection type image display device that displays a color image on a screen (projection surface) SCR. The projector 1 includes three light modulation devices corresponding to the respective colors of red light LR, green light LG, and blue light LB.

[0012] 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 combining element 5, and a projection optical device 6.

[0013] 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 modulation device 4B. Detailed configurations of the first illumination device 20 and the second illumination device 21 will be described later.

[0014] In the following, in the drawings, an XYZ orthogonal coordinate system is used for explanation as necessary. The Z axis is an axis along the up-down direction of the projector 1. The X axis is an axis parallel to the optical axis AX1 of the first lighting device 20 and the optical axis AX2 of the second lighting device 21, and is an axis along the front-rear direction of the projector 1. The Y axis is an axis perpendicular to the X axis and the Z axis, and is an axis along the left-right direction of the projector 1. These notations are for explaining the arrangement relationship of each component of the projector 1, and do not limit the installation posture or direction of the projector 1. The optical axis AX1 of the first lighting device 20 is the central 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 central axis of the blue light LB emitted from the second lighting device 21.

[0015] 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 reflecting mirror 8a, and a second reflecting mirror 8b.

[0016] 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 reflecting mirror 8b is disposed in the optical path of the green light LG. The second reflecting mirror 8b reflects the green light LG reflected by the dichroic mirror 7 toward the optical modulation device 4G. The first reflecting mirror 8a is disposed in the optical path of the red light LR. The first reflecting mirror 8a reflects the red light LR transmitted through the dichroic mirror 7 toward the optical modulation device 4R.

[0017] On the other hand, the blue light LB emitted from the second illumination device 21 is reflected by the reflecting mirror 9 towards the light modulation device 4B.

[0018] The configuration of the second illumination device 21 will be described below. The second illumination 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. Note that the light source unit 81 is not limited to a semiconductor laser, and may be composed of an LED that emits blue light.

[0019] The condenser lens 82 is composed of a convex lens. The condenser lens 82 causes the blue light LB emitted from the light source unit 81 to enter the diffusion plate 83 in a substantially condensed state. The diffusion plate 83 diffuses the blue light LB emitted from the condenser lens 82 with a predetermined diffusion degree, and generates blue light LB having a substantially uniform light distribution similar to that of the fluorescent light Y emitted from the first lighting device 20. As the diffusion plate 83, for example, ground glass made of optical glass is used.

[0020] The blue light LB diffused by the diffusion plate 83 is incident on the rod lens 86. The rod lens 86 has a prismatic shape extending along the optical axis AX2 direction of the second illumination device 21. The rod lens 86 has a light incident end face 86a and a light exit end face 86b located on the opposite side to the light incident end face 86a. The diffusion plate 83 is fixed to the light incident end face 86a of the rod lens 86 via an optical adhesive (not shown). It is desirable that the refractive index of the diffusion plate 83 and the refractive index of the rod lens 86 match as closely as possible.

[0021] The blue light LB is propagated while being totally reflected inside the rod lens 86, and is emitted from the light emitting end surface 86b with the uniformity of the illuminance distribution being enhanced. The blue light LB emitted from the rod lens 86 is incident on the relay lens 87. The relay lens 87 causes the blue light LB, whose uniformity of the illuminance distribution has been enhanced by the rod lens 86, to be incident on the reflecting mirror 9.

[0022] The shape of the light exit end surface 86b of the rod lens 86 is a rectangle that is approximately similar to the shape of the image forming area of ​​the light modulation device 4B. This allows the blue light LB exiting from the rod lens 86 to efficiently enter the image forming area of ​​the light modulation device 4B.

[0023] The light modulation device 4R modulates the red light LR according to image information to form image light corresponding to the red light LR. The light modulation device 4G modulates the green light LG according to image information to form image light corresponding to the green light LG. The light modulation device 4B modulates the blue light LB according to image information to form image light corresponding to the blue light LB.

[0024] For example, a transmissive liquid crystal panel is used for each of the light modulation devices 4R, 4G, and 4B. A polarizing plate (not shown) is disposed on the entrance side and exit side of each of the liquid crystal panels. The polarizing plate transmits linearly polarized light in a specific direction.

[0025] A field lens 10R is disposed on the incident side of the optical modulation device 4R. A field lens 10G is disposed on the incident side of the optical modulation device 4G. A field lens 10B is disposed on the incident side of the optical modulation device 4B. The field lens 10R collimates the chief ray of the red light LR incident on the optical modulation device 4R. The field lens 10G collimates the chief ray of the green light LG incident on the optical modulation device 4G. The field lens 10B collimates the chief ray of the blue light LB incident on the optical modulation device 4B.

[0026] The light combining element 5 receives the image light emitted from the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B, combines the image light corresponding to the red light LR, the green light LG, and the blue light LB, and emits the combined image light toward the projection optical device 6. For example, a cross dichroic prism is used as the light combining element 5.

[0027] The projection optical device 6 is composed of a plurality of projection lenses. The projection optical device 6 enlarges and projects the image light combined by the light combining element 5 onto the screen SCR. As a result, an image is displayed on the screen SCR.

[0028] The configuration of the first illumination device 20 will be described below. FIG. 2 is a schematic diagram showing a schematic configuration of the first illumination device 20. As shown in FIG. As shown in FIG. 2, the first illumination device 20 includes a light source device 30, a collimating optical system 63, an integrator optical system 31, a polarization conversion element 32, and a superimposing optical system 33.

[0029] Fig. 3 is a perspective view showing a schematic configuration of the light source device 30. Fig. 4 is a plan view of the light source device 30. Fig. 5 is a cross-sectional view of the light source device 30 taken along the line VV in Fig. 3.

[0030] As shown in FIGS. 3 to 5, the light source device 30 includes a wavelength conversion member 50, a light source unit 51, an angle conversion member 52, a support member 54, a position restriction member 65, a pressing member 90, a mirror 53, and an elastic member 58.

[0031] The wavelength conversion member 50 has a rectangular prism shape extending along the X-axis and has six faces. The sides of the wavelength conversion member 50 extending along the X-axis are longer than the sides extending along the Y-axis and the Z-axis. Therefore, the direction in which the X-axis extends corresponds to the longitudinal direction of the wavelength conversion member 50. The length of the side extending along the Y-axis is equal to the length of the side extending along the Z-axis. That is, the cross-sectional shape of the wavelength conversion member 50 cut along a plane along the YZ plane perpendicular to the X-axis is a square. Note that the cross-sectional shape of the wavelength conversion member 50 cut along a plane along the YZ plane may be a rectangle. As an example of the size of the wavelength conversion member 50, the sides extending along the Y-axis and Z-axis have a length of 1 mm, and the side extending along the X-axis has a length of 50 mm.

[0032] The wavelength conversion member 50 has a first surface 50a, a second surface 50b, a third surface 50c, a fourth surface 50d, a fifth surface 50e, and a sixth surface 50f. The first surface 50a and the second surface 50b are perpendicular to the X-axis along the longitudinal direction of the wavelength conversion member 50 and are located on opposite sides of the X-axis. In this embodiment, the first surface 50a is located on one side in the X-axis direction, that is, the +X side, and the second surface 50b is located on the opposite side in the X-axis direction, that is, the -X side.

[0033] The third surface 50c and the fourth surface 50d are orthogonal to the first surface 50a and the second surface 50b, and are located on opposite sides to each other in the Y axis that is orthogonal to the X axis along the longitudinal direction of the wavelength conversion member 50. In this embodiment, the third surface 50c is located on one side in the Y axis direction, that is, the -Y side, and the fourth surface 50d is located on the other side in the Y axis direction, that is, the +Y side.

[0034] The fifth surface 50e and the sixth surface 50f are perpendicular to the third surface 50c and the fourth surface 50d, and are located on opposite sides of the Z axis perpendicular to the X axis and the Y axis. In this embodiment, the fifth surface 50e is located in the +Z direction, which is one side of the Z axis direction, and the sixth surface 50f is located in the -Z direction, which is the other side of the Z axis direction.

[0035] In the following description, when the third surface 50c, the fourth surface 50d, the fifth surface 50e, and the sixth surface 50f are not distinguished from each other, they may be simply referred to as side surfaces 50c, 50d, 50e, and 50f. The side surfaces 50c, 50d, 50e, and 50f in this embodiment correspond to the side surfaces in the claims.

[0036] The wavelength conversion member 50 includes at least a phosphor, and converts the excitation light E having a first wavelength band emitted from the light emitting element 56 of the light source unit 51 into fluorescence Y having a second wavelength band different from the first wavelength band. The excitation light E enters the wavelength conversion member 50 from the third surface 50c. The fluorescence Y is guided inside the wavelength conversion member 50 and then emitted from the first surface 50a. The excitation light E in this embodiment corresponds to the first light in the claims. The fluorescence Y in this embodiment corresponds to the second light in the claims.

[0037] The wavelength conversion member 50 contains a ceramic phosphor made of a polycrystalline phosphor that converts the wavelength of the excitation light E into the fluorescence Y. The second wavelength band of the fluorescence Y is, for example, a yellow wavelength band of 490 to 750 nm. That is, the fluorescence Y is yellow fluorescence containing a red light component and a green light component. The wavelength conversion member 50 may contain a single crystal phosphor instead of the polycrystalline phosphor. Alternatively, the wavelength conversion member 50 may be made of fluorescent glass. Alternatively, the wavelength conversion member 50 may be made of a material in which a large number of phosphor particles are dispersed in a binder made of glass or resin. The wavelength conversion member 50 made of this type of material converts the excitation light E into the fluorescence Y.

[0038] Specifically, the material of the wavelength conversion member 50 includes, for example, an yttrium-aluminum-garnet (YAG) phosphor. Taking YAG:Ce containing cerium (Ce) as an activator as an example, the material of the wavelength conversion member 50 may be a material obtained by mixing raw material powders containing constituent elements such as Y2O3, Al2O3, and CeO3 and causing a solid-phase reaction, Y-Al-O amorphous particles obtained by a wet method such as a coprecipitation method or a sol-gel method, or YAG particles obtained by a gas phase method such as a spray drying method, a flame pyrolysis method, or a thermal plasma method.

[0039] The light source unit 51 has a substrate 55, a plurality of light-emitting elements 56, and wiring (not shown). The light source unit 51 may also have other optical members such as a light guide plate, a diffusion plate, and a lens. The plurality of light-emitting elements 56 are provided on one surface of the substrate 55. The light source unit 51 of this embodiment has a plurality of light-emitting elements 56, but the number of the light-emitting elements 56 is not particularly limited.

[0040] The light emitting element 56 has a light emitting surface 56a and emits excitation light E of a first wavelength band from the light emitting surface 56a. The light emitting element 56 is, for example, a light emitting diode (LED). The light emitting element 56 is disposed facing the third surface 50c of the wavelength conversion member 50 and emits excitation light E toward the third surface 50c. The first wavelength band is, for example, a wavelength band from blue to purple of 400 nm to 480 nm, and the peak wavelength is, for example, 445 nm. In this way, the light source unit 51 is provided facing the third surface 50c, which is one of the four side surfaces 50c, 50d, 50e, and 50f along the longitudinal direction of the wavelength conversion member 50.

[0041] The support member 54 has a groove 154 that supports the wavelength conversion member 50. The support member 54 comes into contact with the wavelength conversion member 50 inside the groove 154, thereby diffusing and dissipating heat generated in the wavelength conversion member 50 to the outside. For this reason, it is desirable that the support member 54 be made of a material that has a predetermined strength and high thermal conductivity. As a material for the support member 54, for example, a metal such as aluminum, stainless steel, copper, etc. is used, and in particular, it is desirable to use an aluminum alloy such as 6061 series. The specific configuration of the support member 54 will be described later.

[0042] In the present embodiment, the support member 54 is configured as an integral member made of a metal such as aluminum, stainless steel, copper, etc. This configuration simplifies the configuration of the support member 54 and stabilizes the stress state at the bonding surface between the angle conversion member 52 and the wavelength conversion member 50, which will be described later.

[0043] The linear expansion coefficient of aluminum constituting the support member 54 is 23×10 -6 / ℃. The linear expansion coefficient of SUS304 (stainless steel) is 17.3×10 -6 / ℃. The linear expansion coefficient of copper is 16.7×10 -6 / °C. In contrast, the linear expansion coefficient of YAG constituting the wavelength conversion member 50 is 8×10 -6 / ° C. In this way, whichever material is selected, the linear expansion coefficient of the support member 54 is greater than the linear expansion coefficient of the wavelength conversion member 50.

[0044] The position restricting member 65, together with the pressing member 90, restricts the position of the wavelength conversion member 50 relative to the support member 54. As shown in FIG. 4, the position restricting member 65 abuts against the fifth surface 50e and the sixth surface 50f of the wavelength conversion member 50, and restricts the movement of the wavelength conversion member 50 to the +Z side and the -Z side along the Z-axis direction. The position restricting member 65 is made of a pair of members and is accommodated in the first accommodation groove portion 541 provided on both sides of the groove portion 154 of the support member 54. The position restricting member 65 is fixed to the support member 54 by a screw 97. In this embodiment, the pair of position restricting members 65 are provided at two locations, one on the side close to the first surface 50a of the wavelength conversion member 50 and the other on the side close to the second surface 50b, but the number and installation positions of the position restricting members 65 are not limited.

[0045] As shown in FIG. 5, the pressing member 90 restricts the movement of the wavelength conversion member 50 in the Y-axis direction relative to the support member 54 inside the groove 154. The pressing member 90 is disposed facing the support surface 54s, which is the bottom surface of the groove 154. As a result, the pressing member 90 restricts the wavelength conversion member 50 from moving to the -Y side inside the groove 154 by pressing the wavelength conversion member 50 toward the support surface 54s. That is, the pressing member 90 is designed not only to be in contact with the wavelength conversion member 50, but also to be in contact with the wavelength conversion member 50 in an elastically deformed state and to press the wavelength conversion member 50 with a predetermined pressing force by the elastic restoring force. For this reason, the pressing member 90 is made of an elastically deformable material. Specifically, the pressing member 90 is made of a leaf spring made of a stainless steel material such as SUS304.

[0046] The support surface 54s of the support member 54 may have slight irregularities or undulations due to the processing accuracy and material of the groove portion 154. Therefore, simply placing the wavelength conversion member 50 on such a support surface 54s may result in insufficient contact between the wavelength conversion member 50 and the support member 54. In this case, the contact area between the wavelength conversion member 50 and the support member 54 becomes smaller than it should be, and heat transfer from the wavelength conversion member 50 to the support member 54 becomes insufficient. This may cause the temperature of the wavelength conversion member 50 to rise, resulting in problems such as a decrease in wavelength conversion efficiency and a decrease in reliability. To address this problem, in the present embodiment, the wavelength conversion member 50 is pressed against the support member 54 by the pressing member 90, thereby suppressing the above problems.

[0047] As shown in FIG. 3 and FIG. 4, the pressing member 90 is composed of a first pressing member 910 and a second pressing member 920. The first pressing member 910 and the second pressing member 920 are members having the same shape, size, and constituent material. The first pressing member 910 and the second pressing member 920 may differ in at least one of the shape, size, and constituent material. The first pressing member 910 and the second pressing member 920 are provided at an interval along the longitudinal direction (X-axis direction) of the wavelength conversion member 50. The first pressing member 910 of this embodiment corresponds to the first pressing portion in the claims. The second pressing member 920 of this embodiment corresponds to the second pressing portion in the claims.

[0048] 4, the first pressing member 910 and the second pressing member 920 are each housed in a second housing groove portion 542 provided in the support member 54. Furthermore, the first pressing member 910 and the second pressing member 920 are each fixed to the support member 54 by a screw 96 in the second housing groove portion 542.

[0049] As shown in FIG. 6, a virtual cross section DM is assumed that divides the wavelength conversion member 50 into two equal parts in the longitudinal direction. Of the two regions into which the wavelength conversion member 50 is divided with the virtual cross section DM as a boundary, a region including the first surface 50a of the wavelength conversion member 50 is defined as a first region 50X1, and a region including the second surface 50b of the wavelength conversion member 50 is defined as a second region 50X2. The first pressing member 910 is provided in the first region 50X1. The second pressing member 920 is provided in the second region 50X2. That is, the first pressing member 910 presses the wavelength conversion member 50 from the side surface 50c in the first region 50X1 close to the angle conversion member 52. The second pressing member 920 presses the wavelength conversion member 50 from the side surface 50c in the second region 50X2 far from the angle conversion member 52.

[0050] The pressing force F1 with which the first pressing member 910 presses the wavelength conversion member 50 and the pressing force F2 with which the second pressing member 920 presses the wavelength conversion member 50 are different from each other. Specifically, the pressing force F1 with which the first pressing member 910 presses the wavelength conversion member 50 is greater than the pressing force F2 with which the second pressing member 920 presses the wavelength conversion member 50. In other words, the first region 50X1 closer to the angle conversion member 52 is pressed with a greater pressing force than the second region 50X2 farther from the angle conversion member 52.

[0051] The pressing force of the pressing member 90 pressing the wavelength conversion member 50 is preferably 1N or more and 20N or less overall. In addition, the ratio F1:F2 of the pressing force F1 of the first pressing member 910 and the pressing force F2 of the second pressing member 920 is preferably 1.5:1 or more and 4:1 or less. Therefore, the entire pressing force is distributed based on the above ratio. For example, when the pressing force of the entire pressing member 90 is 1N, it is preferable that the pressing force F1 of the first pressing member 910 is 0.6 to 0.8N, and the pressing force F2 of the second pressing member 920 is 0.2 to 0.4N. When the pressing force of the entire pressing member 90 is 20N, it is preferable that the pressing force F1 of the first pressing member 910 is 12 to 16N, and the pressing force F2 of the second pressing member 920 is 4 to 8N.

[0052] In this embodiment, one pressing member 910, 920 is provided for each of the first region 50X1 and the second region 50X2, thereby reducing the blocking of the excitation light E by the pressing member 90, as described below. Instead of this configuration, a plurality of first pressing members may be provided for the first region 50X1, and a plurality of second pressing members may be provided for the second region 50X2. The number of first pressing members provided in the first region 50X1 and the number of second pressing members provided in the second region 50X2 may be different from each other. Regardless of the number of pressing members, it is only necessary that the total pressing force of the plurality of first pressing members provided in the first region 50X1 is greater than the total pressing force of the plurality of second pressing members provided in the second region 50X2. In this case, the multiple first pressing members provided in the first region 50X1 correspond to a first pressing portion in the claims, and the multiple second pressing members provided in the second region 50X2 correspond to a second pressing portion in the claims.

[0053] Moreover, it is desirable that each of the pressing members 90 is disposed at a position that does not overlap with the light-emitting element 56 of the light source unit 51 when viewed from the Y-axis direction. According to this configuration, the pressing members 90 do not block the excitation light E emitted from the light-emitting element 56.

[0054] In this embodiment, the support member 54 has a support surface 54s that supports the wavelength conversion member 50, the light emitting element 56 is disposed facing the support surface 54s, and the pressing member 90 presses the wavelength conversion member 50 from the side surface 50c on which the excitation light E from the light emitting element 56 is incident toward the support surface 54s. In the wavelength conversion member 50, the temperature of the side surface 50c on which the excitation light E is incident is more likely to rise than the temperatures of the other side surfaces 50d, 50e, and 50f, so that the amount of elongation near the side surface 50c on which the excitation light E is incident is greater than the amount of elongation near the other side surfaces 50d, 50e, and 50f. Considering this point, according to the above configuration, the pressing member 90 presses the side surface 50c on which the amount of elongation is relatively large, so that warping of the wavelength conversion member 50 is suppressed and the wavelength conversion member 50 can be effectively pressed.

[0055] As shown in FIG. 2, the mirror 53 is provided on the second surface 50b of the wavelength conversion member 50. The mirror 53 guides light inside the wavelength conversion member 50 and reflects the fluorescence Y that reaches the second surface 50b. The mirror 53 is configured separately from the wavelength conversion member 50 and is provided in contact with the second surface 50b of the wavelength conversion member 50. The mirror 53 has a reflection surface 53r in which a metal film or a dielectric multilayer film is formed on one surface of a plate made of metal or the like. The mirror 53 may be made of a metal film or a dielectric multilayer film formed directly on the second surface 50b of the wavelength conversion member 50. The mirror 53 of this embodiment corresponds to a reflection member in the claims.

[0056] The elastic member 58 is elastically deformable in the longitudinal direction of the wavelength conversion member 50, and presses the mirror 53 from the outer surface 53t side toward the second surface 50b of the wavelength conversion member 50. As a result, the reflecting surface 53r of the mirror 53 is in close contact with the second surface 50b of the wavelength conversion member 50. As shown in FIG. 3, the elastic member 58 has a pressing portion 581 and an elastic portion 582. The elastic member 58 is made of a plate-shaped metal material having elasticity, and the pressing portion 581 and the elastic portion 582 are integrally formed. With this configuration, the pressing portion 581 can reliably press the mirror 53, and the elastic portion 582 can apply a pressing force to the pressing portion 581. The pressing portion 581 abuts against the outer surface 53t of the mirror 53 and presses the mirror 53.

[0057] As shown in FIG. 2, in the light source device 30, when the excitation light E emitted from the light source unit 51 is incident on the wavelength conversion member 50, the phosphor contained in the wavelength conversion member 50 is excited, and the fluorescence Y is emitted from an arbitrary light-emitting point. The fluorescence Y travels in all directions from an arbitrary light-emitting point, and the fluorescence Y traveling toward the four side surfaces 50c, 50d, 50e, and 50f travels toward the first surface 50a or the second surface 50b while repeating total reflection at multiple points on the side surfaces 50c, 50d, 50e, and 50f. The first surface 50a emits the fluorescence Y that has been guided inside the wavelength conversion member 50. In the case of this embodiment, the fluorescence Y traveling toward the first surface 50a is emitted from the first surface 50a and enters the angle conversion member 52 provided on the first surface 50a. The fluorescence Y traveling toward the second surface 50b is reflected by the mirror 53 and then travels toward the first surface 50a.

[0058] Of the excitation light E incident on the wavelength conversion member 50, a portion of the excitation light E that is not used to excite the phosphor is reflected by the members surrounding the wavelength conversion member 50, including the light emitting element 56 of the light source unit 51, or by the mirror 53 provided on the second surface 50b. Therefore, a portion of the excitation light E is trapped inside the wavelength conversion member 50 and reused.

[0059] 4, support member 54 is a plate-like member having a rectangular planar shape and including groove portion 154, a first accommodating groove portion 541, a second accommodating groove portion 542, and an accommodating recess 545. Groove portion 154 extends in the X-axis direction along the longitudinal direction of wavelength conversion member 50, and accommodates wavelength conversion member 50.

[0060] 5, the groove 154 has a cross section perpendicular to the X-axis direction that is substantially U-shaped. The groove 154 has a support surface 54s, a first wall surface 54a, and a second wall surface 54b. The groove 154 is formed by cutting the material of the support member 54, which is a metal such as aluminum, iron, or stainless steel.

[0061] The support surface 54s corresponds to the bottom surface of the groove portion 154. In the case of this embodiment, the support surface 54s is a surface extending parallel to the XZ plane, abuts against the fourth surface 50d of the wavelength conversion member 50, and supports the fourth surface 50d. The first wall surface 54a corresponds to one side surface of the groove portion 154. The first wall surface 54a faces the fifth surface 50e of the wavelength conversion member 50 and is spaced from the fifth surface 50e. That is, a gap is provided between the first wall surface 54a and the fifth surface 50e of the wavelength conversion member 50. The second wall surface 54b corresponds to the other side surface of the groove portion 154. The second wall surface 54b faces the sixth surface 50f of the wavelength conversion member 50 and is spaced from the sixth surface 50f. That is, a gap is provided between the second wall surface 54b and the sixth surface 50f of the wavelength conversion member 50.

[0062] The first wall surface 54a has a first portion 54a1 located on the side farther from the support surface 54s and a second portion 54a2 located on the side closer to the support surface 54s. The first portion 54a1 extends in a direction perpendicular to the support surface 54s, i.e., parallel to the XY plane. The second portion 54a2 is inclined so as to approach the fifth surface 50e from the first portion 54a1 side toward the support surface 54s side. In other words, the distance between the second portion 54a2 on the side closer to the support surface 54s and the fifth surface 50e is smaller than the distance between the second portion 54a2 on the side closer to the support surface 54s and the fifth surface 50e on the side closer to the first portion 54a1.

[0063] The second wall surface 54b has a third portion 54b3 located on the side farther from the support surface 54s and a fourth portion 54b4 located on the side closer to the support surface 54s. The third portion 54b3 extends in a direction perpendicular to the support surface 54s, i.e., parallel to the XY plane. The fourth portion 54b4 is inclined so as to approach the sixth surface 50f from the third portion 54b3 side toward the support surface 54s side. In other words, the distance between the fourth portion 54b4 on the side closer to the support surface 54s and the sixth surface 50f is smaller than the distance between the fourth portion 54b4 on the side closer to the third portion 54b3 and the sixth surface 50f.

[0064] Each of the first wall surface 54a and the second wall surface 54b is made of a surface of a metal such as aluminum, iron, or stainless steel, which is a material of the support member 54. More specifically, each of the first wall surface 54a and the second wall surface 54b is made of a processed surface that is a mirror-finished surface of the above-mentioned metal surface. As a result, each of the first wall surface 54a and the second wall surface 54b has light reflectivity and reflects the incident excitation light E. Note that each of the first wall surface 54a and the second wall surface 54b may be made of another metal film or a dielectric multilayer film formed on the surface of a metal such as aluminum, iron, or stainless steel.

[0065] The dimension W1 of the light-emitting surface 56a of the light-emitting element 56 along the Z-axis direction is larger than the width B2 of the wavelength conversion member 50 along the Z-axis direction. The width of the wavelength conversion member 50 in this embodiment in the Z-axis direction is equal throughout the longitudinal direction. As a result, both ends of the light-emitting surface 56a of the light-emitting element 56 protrude outside the third surface 50c of the wavelength conversion member 50 in the Z-axis direction. Specifically, both ends of the light-emitting surface 56a of the light-emitting element 56 protrude to positions overlapping the gap between the fifth surface 50e and the first wall surface 54a and the gap between the sixth surface 50f and the second wall surface 54b. In other words, when the light-emitting surface 56a is viewed along the Y-axis direction from the support surface 54s, a part of the light-emitting surface 56a overlaps with the third surface 50c, and another part of the light-emitting surface 56a overlaps with the gap between the fifth surface 50e and the first wall surface 54a and the gap between the sixth surface 50f and the second wall surface 54b.

[0066] The width D2 of the support surface 54s of the support member 54 along the Z-axis direction is larger than the width B2 of the wavelength conversion member 50 along the Z-axis direction. As a result, both ends of the support surface 54s in the Z-axis direction protrude outside the fourth surface 50d of the wavelength conversion member 50. In other words, when the support surface 54s is viewed from the light-emitting surface 56a along the Y-axis direction, a part of the support surface 54s overlaps with the fourth surface 50d, and another part of the support surface 54s is exposed outside the fourth surface 50d. In this way, the support surface 54s has an exposed portion 54r exposed to the outside of the wavelength conversion member 50.

[0067] A part of the excitation light E2 emitted from the light emitting surface 56a of the light emitting element 56 passes through the gap between the fifth surface 50e and the first portion 54a1 of the wavelength conversion member 50, and then enters the second portion 54a2 inclined with respect to the support surface 54s. At this time, the excitation light E2 is reflected by the second portion 54a2 and enters the fifth surface 50e of the wavelength conversion member 50. In this way, the excitation light E2 passing through the gap between the fifth surface 50e and the first wall surface 54a of the wavelength conversion member 50 is more likely to enter the fifth surface 50e, so that the amount of the excitation light E reflected by the support surface 54s and returning to the side of the light source unit 51 can be reduced. In addition, a part of the excitation light E is reflected by the first portion 54a1 extending perpendicularly to the support surface 54s and enters the fifth surface 50e of the wavelength conversion member 50. The same applies to the excitation light E2 entering the gap between the sixth surface 50f and the second wall surface 54b of the wavelength conversion member 50. This makes it possible to realize a light source device 30 that has high utilization efficiency of the excitation light E and that makes it easy to obtain fluorescence Y having a desired intensity.

[0068] 4, the first accommodating groove 541 is provided on the upper surface of the supporting member 54, and is a groove recessed into the upper surface of the supporting member 54. The first accommodating groove 541 is provided on both sides in the Z-axis direction of the groove 154. The first accommodating groove 541 accommodates a position restricting member 65 that restricts the position of the wavelength conversion member 50 in the Z-axis direction.

[0069] The second accommodating groove 542 is provided on the upper surface of the support member 54 and is a groove recessed into the upper surface of the support member 54. The second accommodating groove 542 is provided on both sides in the Z-axis direction of the groove 154. The second accommodating groove 542 accommodates each of the first pressing member 910 and the second pressing member 920 that press the wavelength conversion member 50 toward the support surface 54s of the support member 54.

[0070] 3, the accommodating recess 545 is provided on the upper surface of the supporting member 54, and is a recess that is recessed with respect to the upper surface of the supporting member 54. The accommodating recess 545 is provided on the +X side of the groove portion 154, i.e., the side where the first surface 50a of the wavelength converting member 50 is located. The accommodating recess 545 accommodates the angle converting member 52 joined to the wavelength converting member 50.

[0071] The angle conversion member 52 is provided on the first surface 50a of the wavelength conversion member 50. The angle conversion member 52 is made of a compound parabolic concentrator (CPC). The angle conversion member 52 is made of a light-transmitting material such as borosilicate glass such as N-BK7, or a cycloolefin resin such as E-48R.

[0072] The angle conversion member 52 has an incident end face 52a on which the fluorescence Y emitted from the first surface 50a of the wavelength conversion member 50 is incident, an exit end face 52b from which the fluorescence Y incident from the incident end face 52a is emitted, and four side faces 52c in contact with each of the incident end face 52a and the exit end face 52b. Each of the four side faces 52c functions as a reflecting surface that reflects the fluorescence Y incident from the incident end face 52a toward the exit end face 52b. Hereinafter, the side faces 52c may also be referred to as reflecting surfaces 52c.

[0073] The cross-sectional area of ​​the angle conversion member 52 perpendicular to the optical axis J gradually increases from the incident end face 52a toward the exit end face 52b. Therefore, the area of ​​the exit end face 52b is larger than the area of ​​the incident end face 52a. Furthermore, the width of each reflecting surface 52c in a direction perpendicular to the optical axis J gradually increases from the incident end face 52a toward the exit end face 52b. When the angle conversion member 52 is viewed from a direction perpendicular to the optical axis J (the Z-axis direction), the shape of each reflecting surface is parabolic.

[0074] An axis that passes through the centers of emission end face 52b and incidence end face 52a and is parallel to the X-axis is defined as optical axis J of angle conversion member 52. Optical axis J of angle conversion member 52 coincides with optical axis AX1 of first illumination device 20. Hereinafter, of angle conversion member 52, a portion that includes incidence end face 52a and emission end face 52b and that substantially contributes to the angle conversion of fluorescence Y is referred to as angle conversion member main body 521, and a portion that protrudes outward from emission end face 52b with respect to optical axis J is referred to as flange portion 522.

[0075] 2, the fluorescence Y incident on the angle conversion member 52 changes direction each time it is totally reflected by the reflecting surface 52c while traveling inside the angle conversion member 52 so as to approach a direction parallel to the optical axis J. In this way, the angle conversion member 52 converts the emission angle distribution of the fluorescence Y emitted from the second surface 50b of the wavelength conversion member 50. Specifically, the angle conversion member 52 makes the maximum emission angle of the fluorescence Y at the emission end surface 52b smaller than the maximum incidence angle of the fluorescence Y at the incidence end surface 52a.

[0076] Generally, the etendue of light, which is defined as the product of the area of ​​the light emission region and the solid angle (maximum emission angle) of light, is preserved, and therefore the etendue of the fluorescence Y is preserved both before and after transmission through the angle conversion member 52. As described above, the angle conversion member 52 has a configuration in which the area of ​​the emission end face 52b is larger than the area of ​​the incidence end face 52a. Therefore, from the viewpoint of etendue preservation, the angle conversion member 52 can make the maximum emission angle of the fluorescence Y at the emission end face 52b smaller than the maximum incidence angle of the fluorescence Y incident on the incidence end face 52a.

[0077] As shown in FIG. 4, the wavelength conversion member 50 and the angle conversion member 52 are bonded together by a bonding layer 41. The bonding layer 41 is made of an adhesive and is provided between the first surface 50a of the wavelength conversion member 50 and the incident end surface 52a of the angle conversion member 52. It is preferable that the bonding layer 41 is provided in the entire area between the first surface 50a and the incident end surface 52a. In this case, no gap (air layer) exists between the wavelength conversion member 50 and the angle conversion member 52. The bonding layer 41 has optical transparency. As a material for the bonding layer 41, for example, a phenyl-based silicone resin adhesive having thermosetting or ultraviolet curing properties is used.

[0078] If a gap is provided between the wavelength conversion member 50 and the angle conversion member 52, the fluorescence Y that reaches the first surface 50a of the wavelength conversion member 50 and is incident on the first surface 50a at an angle equal to or greater than the critical angle is totally reflected by the first surface 50a and cannot be incident on the angle conversion member 52. In contrast, as in this embodiment, if the bonding layer 41 is present in the entire region between the wavelength conversion member 50 and the angle conversion member 52 and no gap is present, the amount of fluorescence Y that cannot be incident on the angle conversion member 52 can be reduced. From this perspective, it is desirable that the refractive index of the wavelength conversion member 50, the refractive index of the angle conversion member 52, and the bonding layer 41 match as closely as possible.

[0079] However, in general, the wavelength conversion member 50 is made of a material containing a phosphor such as YAG, and the angle conversion member 52 is made of a light-transmitting material such as borosilicate glass, so that the wavelength conversion member 50 has a refractive index of about 1.8, and the angle conversion member 52 has a refractive index of about 1.50 to 1.55. Thus, it is difficult to match the refractive index of the wavelength conversion member 50 and the refractive index of the angle conversion member 52. Therefore, it is desirable to match at least the refractive index of the angle conversion member 52 and the refractive index of the bonding layer 41 as much as possible. When borosilicate glass is used for the angle conversion member 52, the refractive index of the angle conversion member 52 is about 1.5, and when a phenyl-based silicone resin is used as the adhesive for the bonding layer 41, the refractive index of the bonding layer 41 is about 1.5, so that the refractive indices of the two are approximately the same.

[0080] 3 and 6, the angle conversion member 52 is fixed in the accommodation recess 545 via a bonding material 98 such as an adhesive provided at the end of the support member 54. The wavelength conversion member 50 and the angle conversion member 52 are separated by a distance of, for example, 1 mm. 2Since the angle conversion member 52 is bonded with a small bonding area of ​​about 10 mm, if the angle conversion member 52 is not supported anywhere when an external force such as an impact is applied, there is a risk that the angle conversion member 52 will peel off from the wavelength conversion member 50. In contrast, if the angle conversion member 52 is fixed to the support member 54 by the bonding material 98 as in the present embodiment, the weight of the angle conversion member 52 is supported by the support member 54, so that the risk that the angle conversion member 52 will peel off from the wavelength conversion member 50 can be reduced even if an external force such as an impact is applied. Even if the angle conversion member 52 does not peel off from the wavelength conversion member 50, a decrease in the amount of fluorescence Y incident on the downstream optical system of the light source device 30 caused by a positional deviation of the angle conversion member 52 can be suppressed. The angle conversion member 52 does not necessarily have to be fixed to the support member 54 via the bonding material 98 such as an adhesive, and may be mechanically fixed to the support member 54 via another support member made of, for example, sheet metal.

[0081] In this way, while the angle conversion member 52 is fixed to the support member 54, the end of the two longitudinal ends of the wavelength conversion member 50 including the second surface 50b is pressed against the mirror 53 by the elastic member 58 but is not fixed to the support member 54.

[0082] 2, a collimating optical system 63 including a collimator lens or the like is provided between the light source device 30 and the integrator optical system 31. The collimating optical system 63 further narrows the angular distribution of the fluorescence Y emitted from the angle conversion member 52, and causes the highly parallel fluorescence Y to be incident on the integrator optical system 31. Note that the collimating optical system 63 does not need to be provided when the parallelism of the fluorescence Y emitted from the angle conversion member 52 is sufficiently high.

[0083] The integrator optical system 31 has a first lens array 61 and a second lens array 62. The integrator optical system 31, together with the superimposing optical system 33, functions as a uniform illumination optical system that uniformizes the intensity distribution of the fluorescence Y emitted from the light source device 30 in each of the light modulation devices 4R and 4G, which are the illuminated areas. The fluorescence Y emitted from the collimating optical system 63 is incident on the first lens array 61. The first lens array 61, together with the second lens array 62, constitute the integrator optical system 31.

[0084] The first lens array 61 has a plurality of first lenses 61a. The plurality of first lenses 61a are arranged in a matrix in a plane parallel to the YZ plane perpendicular to the optical axis AX1 of the first illumination device 20. The plurality of first lenses 61a split the fluorescence Y emitted from the angle conversion member 52 into a plurality of partial light beams. The shape of each of the first lenses 61a is a rectangle that is approximately similar to the shape of the image forming areas of the light modulation devices 4R and 4G. As a result, each of the partial light beams emitted from the first lens array 61 is efficiently incident on the image forming areas of the light modulation devices 4R and 4G.

[0085] The fluorescence Y emitted from the first lens array 61 travels toward the second lens array 62. The second lens array 62 is disposed opposite to the first lens array 61. The second lens array 62 has a plurality of second lenses 62a corresponding to the plurality of first lenses 61a of the first lens array 61. The second lens array 62, together with the superimposing optical system 33, forms each of the images of the plurality of first lenses 61a of the first lens array 61 in the vicinity of the image forming areas of the light modulation devices 4R and 4G. The plurality of second lenses 62a are arranged in a matrix in a plane parallel to the YZ plane perpendicular to the optical axis AX1 of the first illumination device 20. The superimposing optical system 33 is composed of one convex lens.

[0086] In this embodiment, the first lenses 61a of the first lens array 61 and the second lenses 62a of the second lens array 62 have the same size, but may have different sizes. In this embodiment, the first lenses 61a of the first lens array 61 and the second lenses 62a of the second lens array 62 are arranged at positions where their optical axes coincide with each other, but may be arranged in an eccentric state with respect to each other.

[0087] The polarization conversion element 32 converts the polarization direction of the fluorescence Y emitted from the second lens array 62. Specifically, the polarization conversion element 32 converts each partial light beam of the fluorescence Y split by the first lens array 61 and emitted from the second lens array 62 into linearly polarized light.

[0088] The polarization conversion element 32 has a polarization separation layer (not shown), a reflection layer (not shown), and a phase difference plate (not shown). The polarization separation layer transmits one linearly polarized component of the polarization components contained in the fluorescence Y emitted from the light source device 30 as is, and reflects the other linearly polarized component in a direction perpendicular to the optical axis AX1. The reflection layer reflects the other linearly polarized component reflected by the polarization separation layer in a direction parallel to the optical axis AX1. The phase difference plate converts the other linearly polarized component reflected by the reflection layer into one linearly polarized component.

[0089] [Effects of the first embodiment] The light source device 30 of this embodiment includes a light emitting element 56 that emits excitation light E, a wavelength conversion member 50 that guides fluorescence Y generated from the excitation light E emitted from the light emitting element 56, an angle conversion member 52 that converts the angular distribution of the fluorescence Y emitted from the wavelength conversion member 50, a support member 54 that supports the wavelength conversion member 50, and a pressing member 90 that presses the wavelength conversion member 50 against the support member 54. The wavelength conversion member 50 has a first surface 50a and a second surface 50b that are located on opposite sides in the longitudinal direction of the wavelength conversion member 50, and side surfaces 50c, 50d, 50e, and 50f that contact the first surface 50a and the second surface 50b, respectively. The angle conversion member 52 has an incident end surface 52a into which the fluorescence Y emitted from the wavelength conversion member 50 is incident, and an exit end surface 52b from which the fluorescence Y incident from the incident end surface 52a is emitted. Fluorescence Y guided through the wavelength conversion member 50 is emitted from the first surface 50a toward the incident end surface 52a. Excitation light E emitted from the light emitting element 56 is incident on the wavelength conversion member 50 from the side surface 50c. The angle conversion member 52 is fixed to the support member 54. Of the longitudinal ends of the wavelength conversion member 50, the end including the second surface 50b is not fixed to the support member 54. The linear expansion coefficient of the support member 54 is larger than that of the wavelength conversion member 50. The pressing member 90 has a first pressing member 910 that presses the wavelength conversion member 50 from the side surface 50c in the first region 50X1, and a second pressing member 920 that presses the wavelength conversion member 50 from the side surface 50c in the second region 50X2, and a pressing force F1 with which the first pressing member 910 presses the wavelength conversion member 50 is greater than a pressing force F2 with which the second pressing member 920 presses the wavelength conversion member 50.

[0090] The present inventor has noticed that when a wavelength conversion member is pressed in the longitudinal direction of the wavelength conversion member using a plurality of pressing members, if the wavelength conversion member thermally expands in a state in which the pressing force of one pressing member is different from that of the other pressing members, the wavelength conversion member expands on both sides of the point pressed with the relatively large pressing force as a fulcrum. From this viewpoint, the present inventor has performed the following simulation.

[0091] FIG. 7 is a schematic diagram showing a light source device 130 of a comparative example. As shown in FIG. 7, as a comparative example, a light source device 130 is assumed in which, contrary to the present embodiment, the pressing force F2 of the second pressing member 920 in the second region 50X2 is greater than the pressing force F1 of the first pressing member 910 in the first region 50X1. In FIG. 7, the same components as those in the drawings of this embodiment are denoted by the same reference numerals.

[0092] As the simulation conditions, the constituent material of the wavelength conversion member 50 was YAG, and the constituent material of the support member 54 was aluminum. The length in the X-axis direction of the wavelength conversion member 50 was 55.0 mm, and the length in the X-axis direction from the fixed point P1 of the angle conversion member 52 with the support member 54 to the end P2 of the support member 54 was 59.2 mm. The length in the X-axis direction T3 from the center point P3 of the pressing point by the second pressing member 920 to the first surface 50a of the wavelength conversion member 50 was 39.5 mm, and the length in the X-axis direction S3 from the center point P3 of the pressing point by the second pressing member 920 to the fixed point P1 of the angle conversion member with the support member 54 was 45.4 mm.

[0093] Under the above conditions, the amounts of elongation of the wavelength conversion member 50 and the supporting member 54 due to thermal expansion were calculated when the temperatures of the wavelength conversion member 50 and the supporting member 54 rose to 80°C from an initial state of 25°C. The calculated amount of elongation is the amount of elongation of the side of the wavelength conversion member 50 corresponding to the first region 50X1. Because the linear expansion coefficients of the wavelength conversion member 50 and the supporting member 54 are different from each other, the amounts of elongation of the wavelength conversion member 50 and the supporting member 54 due to thermal expansion are also different from each other. Specifically, because the linear expansion coefficient of the supporting member 54 is larger than the linear expansion coefficient of the wavelength conversion member 50, the amount of elongation of the supporting member 54 due to thermal expansion is larger than the amount of elongation of the wavelength conversion member 50.

[0094] The length after thermal expansion from the center point P3 of the pressing point by the second pressing member 920 to the first surface 50a of the wavelength conversion member 50 is T4, and the length after thermal expansion from the center point P3 of the pressing point by the second pressing member 920 to the fixed point P1 of the support member 54 to the angle conversion member 52 is S4. The length T4 after thermal expansion is 39.51738 mm, and the length S4 after thermal expansion is 45.4236 mm. Therefore, the expansion amount ΔT34 of the wavelength conversion member 50 due to thermal expansion is ΔT34 = T4 - T3 = 0.01738 mm. Also, the expansion amount ΔS34 of the support member 54 due to thermal expansion is ΔS34 = S4 - S3 = 0.0236 mm.

[0095] Next, the same calculations as in the comparative example were performed for the light source device 30 of this embodiment. As the simulation conditions, the length T1 in the X-axis direction from the center point P4 of the pressing point by the first pressing member 910 to the first surface 50a of the wavelength conversion member 50 was set to 15.95 mm, and the length S1 in the X-axis direction from the center point P4 of the pressing point by the first pressing member 910 to the fixed point P1 of the support member 54 to the angle conversion member 52 was set to 21.8 mm. The other simulation conditions were the same as those in the comparative example.

[0096] The length after thermal expansion from the center point P4 of the pressing point by the first pressing member 910 to the first surface 50a of the wavelength conversion member 50 is T2, and the length after thermal expansion from the center point P4 of the pressing point by the first pressing member 910 to the fixed point P1 of the support member 54 to the angle conversion member 52 is S2. The length T2 after thermal expansion is 15.95702 mm, and the length S4 after thermal expansion is 21.8113 mm. Therefore, the expansion amount ΔT12 of the wavelength conversion member 50 due to thermal expansion is ΔT12 = T2 - T1 = 0.00702 mm. Also, the expansion amount ΔS12 of the support member due to thermal expansion is ΔS12 = S2 - S1 = 0.0113 mm.

[0097] From the above simulation results, in the comparative example, the support member 54 tries to expand by about 0.024 mm due to thermal expansion, but since the angle conversion member 52 is fixed to the support member 54, the angle conversion member tries to displace by about 0.024 mm to the +X side due to the expansion of the support member. On the other hand, the wavelength conversion member 50 tries to expand by about 0.017 mm due to thermal expansion, but this expansion amount is smaller than the above-mentioned displacement amount of the angle conversion member 52, so the displacement amount of the angle conversion member 52 cannot be offset. As a result, at the joint surface between the angle conversion member 52 and the wavelength conversion member 50, stress is generated in a direction in which the angle conversion member 52 and the wavelength conversion member 50 are pulled apart by 0.007 mm. The stress generated in the direction in which the angle conversion member 52 and the wavelength conversion member 50 are pulled apart may cause the angle conversion member 52 to peel off from the wavelength conversion member 50.

[0098] In contrast, in the case of this embodiment, the support member 54 tends to expand by approximately 0.011 mm due to thermal expansion, and the angle conversion member 52 tends to displace approximately 0.011 mm toward the +X side. Meanwhile, the wavelength conversion member 50 tends to expand by approximately 0.007 mm due to thermal expansion, and therefore stress is generated at the joint surface between the angle conversion member 52 and the wavelength conversion member 50 in a direction in which the angle conversion member 52 and the wavelength conversion member 50 are pulled apart by 0.004 mm. Thus, according to the configuration of this embodiment, the stress generated in the direction in which the angle conversion member 52 and the wavelength conversion member 50 are pulled apart can be made smaller than in the comparative example.

[0099] Of the wavelength conversion member 50, the end portion on the side farther from the angle conversion member 52 (the second surface 50b side) with respect to the boundary of the pressing point by the first pressing member 910 is pressed against the mirror 53 by the elastic member 58, but is a free end that is not fixed to the support member 54. Therefore, the end portion on the second surface 50b side can expand due to thermal expansion without being restrained by the support member 54. Therefore, no unnecessary stress is generated in the wavelength conversion member 50 at the end portion on the second surface 50b side.

[0100] As described above, according to this embodiment, it is possible to reduce the stress generated at the bonding surface between wavelength conversion member 50 and angle conversion member 52 after thermal expansion due to the difference in linear expansion coefficient between wavelength conversion member 50 and support member 54. This makes it possible to reduce the risk that angle conversion member 52 will peel off from wavelength conversion member 50, and to realize a light source device 30 that can stably obtain a desired light output.

[0101] Furthermore, light source device 30 of the present embodiment includes a mirror 53 that reflects fluorescence Y that reaches the second surface 50b of the wavelength conversion member 50, and an elastic member 58 that is elastically deformable in the longitudinal direction of the wavelength conversion member 50 and presses the mirror 53 against the second surface 50b of the wavelength conversion member 50. This makes it possible to hold the second surface 50b of the wavelength conversion member 50 as a free end while suppressing leakage of fluorescence Y from the second surface 50b.

[0102] The projector 1 of this embodiment is equipped with the light source device 30 of this embodiment, and therefore has excellent display quality.

[0103] [Second embodiment] A second embodiment of the present invention will now be described with reference to FIG. The basic configurations of the projector and light source device of the second embodiment are similar to those of the first embodiment, but the configuration of the support member is different from that of the first embodiment, so a description of the basic configurations of the projector and light source device will be omitted. FIG. 8 is a cross-sectional view of a light source device 40 according to the second embodiment. In FIG. 8, components common to those in the drawings used in the first embodiment are given the same reference numerals, and description thereof will be omitted.

[0104] In the light source device 40 of the present embodiment, the support member 54 includes a first support member 547 and a second support member 548. The first support member 547 has a groove portion 154, and supports the wavelength conversion member 50. The second support member 548 is provided so as to surround the first support member 547, and supports the first support member 547.

[0105] As described in the first embodiment, the wall surface of the groove 154 may need to be mirror-finished. Therefore, the portion where the groove 154 is provided requires higher processing accuracy than other portions. For this reason, as in this embodiment, the portion where the groove 154 is provided may be formed of a first support member 547, and a single support member 54 may be formed by combining it with a second support member 548 that forms the portion other than the groove 154. In other words, the support member 54 may be formed by combining a plurality of members. In this way, the peripheral portion of the groove 154 is formed of a different member, so that the workability and processing accuracy of the wall surface of the groove 154 can be easily improved.

[0106] Metals such as aluminum, stainless steel, and copper are used as materials for the first support member 547. Metals such as aluminum, aluminum die-cast, stainless steel, and copper are used as materials for the second support member 548. The constituent materials of the first support member 547 and the second support member 548 may be the same or different. Therefore, the linear expansion coefficients of the first support member 547 and the second support member 548 may be the same or different.

[0107] The linear expansion coefficient of aluminum constituting the first support member 547 and the second support member 548 is 23×10 -6 / ℃. The linear expansion coefficient of SUS304 (stainless steel) is 17.3×10 -6 / ℃. The linear expansion coefficient of copper is 16.7×10 -6 / °C. The linear expansion coefficient of ADC12 (aluminum die-casting) constituting the second support member 548 is 21×10 -6 / °C. In contrast, the linear expansion coefficient of YAG constituting the wavelength conversion member 50 is 8×10 -6 / ° C. In the present embodiment, the linear expansion coefficient of first supporting member 547 and second supporting member 548 is also greater than the linear expansion coefficient of wavelength conversion member 50. The other configuration of the light source device 40 is similar to that of the first embodiment.

[0108] [Effects of the second embodiment] In the present embodiment as well, the pressing force of first pressing member 910 is greater than the pressing force of second pressing member 920, so it is possible to reduce stress at the bonding surface between wavelength conversion member 50 and angle conversion member 52 after thermal expansion caused by the difference in linear expansion coefficient between wavelength conversion member 50 and support member 54. As a result, it is possible to obtain the same effect as in the first embodiment, that is, it is possible to realize light source device 40 that is prevented from peeling off from wavelength conversion member 50 and can stably obtain the desired light output.

[0109] In this embodiment, when the linear expansion coefficient of the first support member 547 and the linear expansion coefficient of the second support member 548 are the same, the stress state at the joint surface between the angle conversion member 52 and the wavelength conversion member 50 can be stabilized. Furthermore, when the linear expansion coefficient of the second support member 548 is larger than that of the first support member 547, the amount of expansion of the second support member 548 during thermal expansion becomes larger than that of the first support member 547. At this time, since the angle conversion member 52 and the second support member 548 are fixed, the angle conversion member 52 tends to be displaced more. Therefore, although the stress at the joint surface between the wavelength conversion member 50 and the angle conversion member 52 is smaller than that of the comparative example, it is relatively large. In contrast, when the linear expansion coefficient of second support member 548 is smaller than that of first support member 547, the amount of elongation of second support member 548 is smaller than that of first support member 547, and therefore the stress at the joint between wavelength conversion member 50 and angle conversion member 52 is smaller than when the linear expansion coefficient of second support member 548 is larger than that of first support member 547.

[0110] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. In the above embodiment, a pressing member is provided facing the third surface of the wavelength conversion member on which the excitation light from the light emitting element is incident, and the pressing member presses the wavelength conversion member from the third surface toward the support surface of the support member. Instead of this configuration, a pressing member may be provided facing a side surface of the wavelength conversion member on which the excitation light is not incident, i.e., the fifth surface or the sixth surface, and the pressing member may press the wavelength conversion member toward the side wall surface of the groove of the support member. Even with this configuration, the same effect as in the above embodiment can be obtained by making the pressing force of the first pressing part in the first region greater than the pressing force of the second pressing part in the second region.

[0111] In the above embodiment, a CPC is used as the angle conversion member. However, instead of a CPC, a tapered rod in the shape of a truncated square pyramid with an exit end face having an area larger than that of an entrance end face may be used.

[0112] In the above embodiment, each wall surface of the groove of the support member has a portion perpendicular to the support surface and a portion inclined to the support surface, but the shape of the groove is not particularly limited, and for example, the entire wall surface of the groove may be perpendicular to the support surface. Also, the wall surface of the groove may be curved.

[0113] In the above embodiment, an example was given in which the present invention was applied to a light source device equipped with a wavelength conversion member, but instead of this configuration, the present invention may be applied to a light source device in which incident light is propagated without wavelength conversion and then, for example, the angular distribution is controlled and emitted. In that case, the wavelength conversion member of the above embodiment replaces the light guide member, and the light emitted from the light emitting element is emitted from the angle conversion member as light of the same wavelength band. When a light guide member without wavelength conversion is used, a light-transmitting member such as quartz or optical glass such as BK7 can be used as a constituent material of the light guide member. The linear expansion coefficient of quartz is 5.9×10 -7 / ℃, and the linear expansion coefficient of BK7 is 7.3 × 10 -6 / ° C. Therefore, in this case as well, the condition that the linear expansion coefficient of the support member is larger than the linear expansion coefficient of the light guide member is satisfied, and the present invention is applicable.

[0114] In addition, the specific description of the shape, number, arrangement, material, etc. of each component of the light source device and the projector is not limited to the above embodiment and can be changed as appropriate. In addition, in the above embodiment, an example in which the light source device according to the present invention is mounted on a projector using a liquid crystal panel is shown, but this is not limited to this. The light source device according to the present invention may be applied to a projector using a digital micromirror device as a light modulation device. In addition, the projector does not need to have multiple light modulation devices, and may have only one light modulation device.

[0115] In the above embodiment, the light source device of the present invention is applied to a projector, but the present invention is not limited to this. The light source device of the present invention can also be applied to lighting fixtures, automobile headlights, and the like.

[0116] [Summary of this disclosure] The following is a summary of this disclosure.

[0117] (Appendix 1) A light emitting element that emits light; a light guiding member that guides the light emitted from the light emitting element; an angle conversion member that converts an angular distribution of the light emitted from the light guiding member; A support member that supports the light guide member; a pressing member that presses the light guide member against the support member; Equipped with The light guiding member is a first surface and a second surface located opposite to each other in a longitudinal direction of the light guide member; a side surface contacting the first surface and a side surface contacting the second surface; having The angle conversion member is an incident end surface on which the light emitted from the light guiding member is incident; an exit end surface from which the light incident from the entrance end surface exits; having the light guided through the light guide member is emitted from the first surface toward the incident end surface, the light emitted from the light emitting element is incident on the light guiding member from the side surface, The angle conversion member is fixed to the support member, an end portion including the second surface among the end portions in the longitudinal direction of the light guiding member is not fixed to the support member; the support member has a linear expansion coefficient greater than the linear expansion coefficient of the light guide member, When a region including the first surface of the light guiding member is defined as a first region and a region including the second surface of the light guiding member is defined as a second region, the region being defined as a virtual cross section that divides the light guiding member into two equal parts in the longitudinal direction, the pressing member has a first pressing portion that presses the light guide member from the side surface in the first region and a second pressing portion that presses the light guide member from the side surface in the second region, a pressing force with which the first pressing portion presses the light guide member is greater than a pressing force with which the second pressing portion presses the light guide member.

[0118] According to the configuration of Supplementary Note 1, since the pressing force of the first pressing portion is greater than that of the second pressing portion, it is possible to reduce stress at the joint surface between the light guiding member and the angle conversion member after thermal expansion caused by the linear expansion coefficient of the support member being greater than that of the light guiding member. As a result, it is possible to realize a light source device that can stably obtain a desired light output by suppressing peeling of the angle conversion member from the light guiding member.

[0119] (Appendix 2) the support member has a support surface that supports the light guide member, The light emitting element is disposed opposite the support surface, 2. The light source device according to claim 1, wherein the pressing member presses the light-guiding member from the side surface onto which the light from the light-emitting element is incident, toward the support surface.

[0120] According to the configuration of Supplementary Note 2, the pressing member presses the side surface on which the degree of thermal expansion increases as light from the light-emitting element is incident, thereby suppressing warping of the light-guiding member and enabling the light-guiding member to be pressed effectively.

[0121] (Appendix 3) a reflecting member that reflects the light that reaches the second surface of the light guiding member; an elastic member that is elastically deformable in the longitudinal direction of the light guide member and presses the reflection member toward the second surface; 3. The light source device according to claim 1 or 2, further comprising:

[0122] According to the configuration of Supplementary Note 3, the reflective member can hold the end portion of the light guide member on the second surface side as a free end, and can suppress leakage of light from the second surface.

[0123] (Appendix 4) 4. The light source device according to claim 1, wherein the support member is configured as a single member.

[0124] According to the configuration of Supplementary Note 4, the configuration of the support member can be simplified, and the state of stress at the joint surface between the angle conversion member and the light guide member can be stabilized.

[0125] (Appendix 5) The light source device according to any one of claims 1 to 3, wherein the support member includes a first support member that supports the light guide member, and a second support member that supports the first support member.

[0126] According to the configuration of Supplementary Note 5, the vicinity of the portion of the support member that supports the light guide member is made of a separate material from the other portions, which makes it easier to improve the workability and processing accuracy of the portion that supports the light guide member.

[0127] (Appendix 6) 6. The light source device according to claim 5, wherein a linear expansion coefficient of the first support member and a linear expansion coefficient of the second support member are equal to each other.

[0128] According to the configuration of Supplementary Note 6, the state of stress on the joint surface between the angle conversion member and the light guide member can be stabilized.

[0129] (Appendix 7) the light emitting element emits a first light having a first wavelength band; The light source device according to any one of claims 1 to 6, wherein the light-guiding member is a wavelength conversion member that includes a phosphor, converts the first light emitted from the light-emitting element into a second light having a second wavelength band different from the first wavelength band, and emits the second light.

[0130] According to the configuration of Supplementary Note 7, it is possible to realize a light source device capable of emitting the second light obtained by wavelength conversion of the first light.

[0131] (Appendix 8) A light source device according to any one of claims 1 to 7, a light modulation device that modulates the light emitted from the light source device in accordance with image information; a projection optical device that projects the light modulated by the light modulation device; A projector equipped with

[0132] According to the configuration of Supplementary Note 8, a projector capable of projecting an image with excellent display quality can be realized. [Explanation of symbols]

[0133] 1... projector, 4B, 4G, 4R... light modulation device, 6... projection optical device, 30, 40... light source device, 50... wavelength conversion member (light guide member), 50a... first surface, 50b... second surface, 50c, 50d, 50e, 50f... side surface (first side surface), 50X1... first region, 50X2... second region, 52... angle conversion member, 52a... incident end surface, 52b... incidence Output end surface, 53...mirror (reflective member), 54...support member, 54s...support surface, 56...light-emitting element, 58...elastic member, 90...pressing member, 910...first pressing member (first pressing portion), 920...second pressing member (second pressing portion), 547...first supporting member, 548...second supporting member, E...excitation light (first light), Y...fluorescence (second light), F1, F2...pressing force.

Claims

1. A light emitting element that emits light; a light guiding member that guides the light emitted from the light emitting element; an angle conversion member that converts an angular distribution of the light emitted from the light guiding member; A support member that supports the light guide member; a pressing member that presses the light guide member against the support member; Equipped with The light guiding member is a first surface and a second surface located opposite to each other in a longitudinal direction of the light guide member; a side surface contacting the first surface and a side surface contacting the second surface; having The angle conversion member is an incident end surface on which the light emitted from the light guiding member is incident; an exit end surface from which the light incident from the entrance end surface exits; having the light guided through the light guide member is emitted from the first surface toward the incident end surface, the light emitted from the light emitting element is incident on the light guiding member from the side surface, The angle conversion member is fixed to the support member, an end portion including the second surface among the end portions in the longitudinal direction of the light guide member is not fixed to the support member; the support member has a linear expansion coefficient greater than the linear expansion coefficient of the light guide member, When a region including the first surface of the light guiding member is defined as a first region and a region including the second surface of the light guiding member is defined as a second region, the region being defined as a virtual cross section that divides the light guiding member into two equal parts in the longitudinal direction, the pressing member has a first pressing portion that presses the light guide member from the side surface in the first region and a second pressing portion that presses the light guide member from the side surface in the second region, a pressing force with which the first pressing portion presses the light guide member is greater than a pressing force with which the second pressing portion presses the light guide member.

2. the support member has a support surface that supports the light guide member, The light emitting element is disposed opposite the support surface, The light source device according to claim 1 , wherein the pressing member presses the light guide member from the side surface onto which the light from the light emitting element is incident, toward the support surface.

3. a reflecting member that reflects the light that reaches the second surface of the light guiding member; an elastic member that is elastically deformable in the longitudinal direction of the light guide member and presses the reflection member toward the second surface; The light source device according to claim 1 , further comprising:

4. The light source device according to claim 1 , wherein the support member is configured as a single unitary member.

5. 3 . The light source device according to claim 1 , wherein the support member comprises a first support member that supports the light guide member, and a second support member that supports the first support member.

6. The light source device according to claim 5 , wherein a linear expansion coefficient of the first support member and a linear expansion coefficient of the second support member are equal to each other.

7. the light-emitting element emits a first light having a first wavelength band; 3. The light source device according to claim 1, wherein the light-guiding member is a wavelength conversion member that contains a phosphor, converts the first light emitted from the light-emitting element into a second light having a second wavelength band different from the first wavelength band, and emits the second light.

8. The light source device according to claim 1 or 2, a light modulation device that modulates the light emitted from the light source device in accordance with image information; a projection optical device that projects the light modulated by the light modulation device; A projector equipped with

Images