Light source device and projector

Abstract

To provide a light source device and a projector that can efficiently extract fluorescence.SOLUTION: A light source device comprises: a first laser light-emitting device that emits first light in a first wavelength range; a wavelength conversion element that converts the first light into second light in a second wavelength range; a substrate that has a first support part supporting the first laser light-emitting device, and a second support part supporting the wavelength conversion element; a light transmissive member that has a first surface and a second surface, is arranged on the opposite side to the substrate with respect to the wavelength conversion element, and allows the first light to be incident on the first surface; a first reflection member that is arranged on the second surface of the light transmissive member and reflects the first light toward the wavelength conversion element; and a condensing optical element that is arranged on a side of the second surface of the light transmissive member, and condenses the light emitted from the wavelength conversion element and transmitted through the light transmissive member. A first distance between the wavelength conversion element and the condensing optical element along an optical axis of the condensing optical element is smaller than a second distance between the first laser light-emitting device and the condensing optical element along the optical axis.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] Patent Document 1 below discloses a light source device that makes excitation light enter a phosphor provided in a recess of a pedestal from an excitation light source attached to an inclined portion of the pedestal, and collimates and extracts the fluorescence emitted from the phosphor with a collimator lens.

[0003] Patent Document 2 below discloses a light source device that has a phosphor and an excitation light source provided on a support surface of a substrate, makes excitation light emitted parallel to the support surface from the excitation light source enter the phosphor, and extracts the fluorescence emitted from the phosphor through a translucent window.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the light source device disclosed in Patent Document 1, since the phosphor is separated from the excitation light source with respect to the collimator lens, a part of the fluorescence emitted from the phosphor at a large emission angle cannot be taken in by the collimator lens, resulting in a problem that the extraction efficiency of the fluorescence decreases.

[0006] Further, in the light source device disclosed in Patent Document 2, since the excitation light source and the phosphor are arranged on the same support surface of the substrate, the heat density of the substrate increases due to the heat of the excitation light source and the phosphor, so that the temperature of the phosphor increases, resulting in a decrease in the light emission efficiency and, as a result, a problem that the extraction efficiency of the fluorescence decreases. [Means for solving the problem]

[0007] To solve the above problems, according to one aspect of the present invention, a substrate having a first laser light-emitting element that emits first light in a first wavelength band, a wavelength conversion element that converts the first light into second light in a second wavelength band different from the first wavelength band, a first support portion that supports the first laser light-emitting element, and a second support portion that supports the wavelength conversion element, and a transparent element having a first surface and a second surface opposite to the first surface, and positioned on the opposite side of the substrate from the wavelength conversion element, through which the first light emitted from the first laser light-emitting element is incident on the first surface A light source device is provided, comprising: an optical member; a first reflective member disposed on the second surface of the light-transmitting member and reflecting the first light emitted from the first laser light-emitting element toward the wavelength conversion element; and a focusing optical element disposed on the side of the second surface of the light-transmitting member and focusing the light emitted from the wavelength conversion element and transmitted through the light-transmitting member, wherein the first distance between the wavelength conversion element and the focusing optical element along the optical axis of the focusing optical element is smaller than the second distance between the first laser light-emitting element and the focusing optical element along the optical axis.

[0008] A second aspect of the present invention provides a projector comprising a light source device according to the first aspect of the present invention, an optical modulator for modulating light from the light source device, and a projection optical device for projecting light modulated by the optical modulator. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows a schematic configuration of the projector according to the first embodiment. [Figure 2] This is a schematic diagram of the lighting system. [Figure 3] This is a plan view of the light source device. [Figure 4] This is a cross-sectional view taken along the line IV-IV in Figure 3. [Figure 5] This is a perspective view showing the configuration of a laser light-emitting element. [Figure 6]This figure shows the irradiation spot of excitation light formed on the first reflective member. [Figure 7A] This figure shows fluorescence incident on the light-gathering optical element in the first comparative example. [Figure 7B] This figure shows fluorescence incident on a light-gathering optical element in an embodiment. [Figure 8A] This figure shows fluorescence incident on the light-gathering optical element in the second comparative example. [Figure 8B] This figure shows fluorescence incident on the light-gathering optical element in the third comparative example. [Figure 9] This is a cross-sectional view showing the main part of the light source device of the second embodiment. [Figure 10] This is a cross-sectional view showing the main part of the light source device of the third embodiment. [Figure 11] This is a cross-sectional view of the light source device according to the fourth embodiment. [Figure 12] This figure shows the configuration of an insulating wall in a modified example. [Figure 13] This figure shows the shape of the reflective member in a modified example. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Please note that the drawings used in the following explanation may be enlarged for convenience to make the features easier to understand, and the dimensional ratios of each component may not be the same as in reality.

[0011] (First Embodiment) An example of a projector according to this embodiment will be described. Figure 1 shows a schematic configuration of the projector according to this embodiment. As shown in Figure 1, the projector 1 of this embodiment is a projection-type image display device that displays a color image on a screen SCR. The projector 1 comprises a color separation optical system 3, optical modulators 4R, 4G, and 4B, a combining optical system 5, a projection optical system 6, and an illumination device 2.

[0012] The color separation optical system 3 separates the white illumination light WL from the illumination device 2 into red light LR, green light LG, and blue light LB. The color separation optical system 3 includes a first dichroic mirror 7a and a second dichroic mirror 7b, a first reflecting mirror 8a, a second reflecting mirror 8b, and a third reflecting mirror 8c, and a first relay lens 9a and a second relay lens 9b.

[0013] The first dichroic mirror 7a separates the illumination light WL from the illumination device 2 into red light LR and the other lights, i.e., green light LG and blue light LB. The first dichroic mirror 7a transmits the separated red light LR and reflects the other lights. The second dichroic mirror 7b reflects the green light LG and transmits the blue light LB.

[0014] The first reflecting mirror 8a reflects the red light LR toward the optical modulation device 4R. The second reflecting mirror 8b and the third reflecting mirror 8c guide the blue light LB to the optical modulation device 4B. The green light LG is reflected from the second dichroic mirror 7b toward the optical modulation device 4G.

[0015] The first relay lens 9a is disposed downstream of the second dichroic mirror 7b in the optical path of the blue light LB. The second relay lens 9b is disposed downstream of the second reflecting mirror 8b in the optical path of the blue light LB.

[0016] The optical modulation device 4R modulates the red light LR according to the image information and forms image light corresponding to the red light LR. The optical modulation device 4G modulates the green light LG according to the image information and forms image light corresponding to the green light LG. The optical modulation device 4B modulates the blue light LB according to the image information and forms image light corresponding to the blue light LB.

[0017] Optical modulators 4R, 4G, and 4B utilize, for example, transmissive liquid crystal panels. Polarizing plates (not shown) are placed on the incident and exit sides of the liquid crystal panel, respectively, to allow only linearly polarized light in a specific direction to pass through.

[0018] Field lenses 10R, 10G, and 10B are positioned on the incident side of optical modulators 4R, 4G, and 4B, respectively. Field lenses 10R, 10G, and 10B parallelize the principal rays of red light LR, green light LG, and blue light LB incident on each of the optical modulators 4R, 4G, and 4B.

[0019] The combining optical system 5 receives image light emitted from optical modulators 4R, 4G, and 4B, combines image light corresponding to red light LR, green light LG, and blue light LB, and emits the combined image light toward the projection optical system 6. For example, a cross dichroic prism is used in the combining optical system 5.

[0020] The projection optical device 6 is composed of multiple lenses. The projection optical device 6 magnifies and projects the image light synthesized by the composite optical system 5 toward the screen SCR. As a result, an image is displayed on the screen SCR.

[0021] (Lighting equipment) Figure 2 is a schematic diagram of the lighting device 2. As shown in Figure 2, the lighting device 2 comprises a light source device 20, a pickup optical system 34, an integrator optical system 35, a polarization conversion element 36, and a superimposed lens 37.

[0022] The light source device 20 emits white illumination light WL toward the pickup optical system 34.

[0023] The pickup optical system 34 is composed of, for example, pickup lenses 34a and 34b. The pickup optical system 34 has the function of picking up and aligning the illumination light WL emitted from the light source device 20.

[0024] The illumination light WL, parallelized by the pickup optical system 34, is incident on the integrator optical system 35. The integrator optical system 35 is composed of, for example, a first lens array 35a and a second lens array 35b. The first lens array 35a includes a plurality of first small lenses 35am, and the second lens array 35b includes a plurality of second small lenses 35bm.

[0025] The first lens array 35a separates the illumination light WL into multiple small beams of light. The first small lens 35am images the small beams of light onto the corresponding second small lens 35bm. The integrator optical system 35 works in cooperation with the superimposed lens 37, which will be described later, to homogenize the illuminance distribution in the image-forming regions of the light modulators 4R and 4G shown in Figure 1, which are the illuminated regions.

[0026] The illumination light WL that has passed through the integrator optical system 35 is incident on the polarization conversion element 36. The polarization conversion element 36 is composed of, for example, a polarization separation film and a phase difference plate (half-wave plate). The polarization conversion element 36 converts the polarization direction of the fluorescence YL to one of the polarization components.

[0027] The illumination light WL that has passed through the polarization conversion element 36 is incident on the superposition lens 37. The illumination light WL emitted from the superposition lens 37 is incident on the color separation optical system 3. The superposition lens 37 uniformly illuminates the illuminated areas of the optical modulators 4R and 4G, i.e., the image forming areas, by superimposing the multiple small beams of light that make up the illumination light WL onto each other.

[0028] The configuration of the light source device 20 will be described in detail below. Figure 3 is a plan view of the light source device 20. Figure 3 is a view of the light source device 20 from a direction along the optical axis ax (Z-axis direction).

[0029] In the following drawings, the various components of the light source device 20 will be described using the XYZ coordinate system as needed. The Z axis is parallel to the optical axis ax of the light source device 20, the X axis is perpendicular to the optical axis ax and parallel to the normal of the substrate 21 that constitutes the light source device 20, and the Y axis and Z axis are perpendicular to each other and are also perpendicular to the X axis. Note that the optical axis ax of the light source device 20 coincides with the illumination optical axis ax1 of the illumination device 2 shown in Figure 2.

[0030] As shown in Figure 3, the light source device 20 comprises a substrate 21, a plurality of laser light-emitting elements 22, a plurality of collimator lenses (parallelization lenses) 23, a wavelength conversion element 24, a light-transmitting member 25, a plurality of reflective members 26, a light-gathering optical element 27, and a side plate portion 28.

[0031] The light source device 20 has a package structure in which a plurality of laser light-emitting elements 22, a plurality of collimator lenses 23, and a wavelength conversion element 24 are housed in a space S composed of a base material 21, a side plate portion 28, and a light-transmitting member 25. It is desirable that the space S be hermetically sealed. The plurality of laser light-emitting elements 22 are arranged to surround the wavelength conversion element 24.

[0032] The base material 21 supports a plurality of laser light-emitting elements 22, a plurality of collimator lenses 23, and a wavelength conversion element 24. The base material 21 is, for example, a metal plate with excellent heat dissipation properties, such as aluminum or copper. The side plate portion 28 surrounds the outer edge of the base material 21 in a frame-like manner and supports the light-transmitting member 25. The side plate portion 28 is provided protruding from one side of the base material 21. In plan view, the side plate portion 28 has an annular shape. The side plate portion 28 maintains a constant distance (spacing) between the base material 21 and the light-transmitting member 25. Therefore, it is preferable that the side plate portion 28 has a predetermined rigidity. Note that a plan view refers to the state in which the object is viewed from a direction along the optical axis ax of the light source device 20 (Z-axis direction). In other words, a plan view refers to the state in which the object is viewed from a direction along the optical axis 27C of the light-gathering optical element 27, which will be described later.

[0033] The side plate portion 28 is preferably made of a material having a coefficient of thermal expansion smaller than that of the base material 21 and larger than that of the translucent member 25. As the material for the side plate portion 28, metal materials such as Kovar, ceramic materials such as alumina, silicon carbide, and silicon nitride are preferably used, with Kovar and alumina being particularly preferred.

[0034] The translucent member 25 transmits light emitted from the wavelength conversion element 24. In a plan view, the translucent member 25 has a circular shape. Examples of materials for forming the translucent member 25 include glass such as borosilicate glass, quartz glass, or synthetic quartz glass, as well as crystal or sapphire.

[0035] The side plate portion 28 and the base material 21, or the translucent member 25 and the side plate portion 28, are joined by a bonding material such as an organic adhesive, a metal bonding material, or an inorganic bonding material. As an organic adhesive, for example, silicone-based adhesives, epoxy resin-based adhesives, acrylic resin-based adhesives, etc., are preferably used. As a metal bonding material, for example, silver solder, gold-tin solder, etc., are preferably used. As an inorganic bonding material, for example, low-melting-point glass, etc., is preferably used.

[0036] When viewed from above, the multiple laser light-emitting elements 22 are arranged in the circumferential direction of the optical axis ax. The multiple laser light-emitting elements 22 are arranged so that pairs of elements face each other across the optical axis ax. In this embodiment, the plurality of laser light-emitting elements 22 include a first laser light-emitting element 22a and a second laser light-emitting element 22b. The first laser light-emitting element 22a and the second laser light-emitting element 22b are arranged on the substrate 21 so as to face each other across the optical axis ax. The first laser light-emitting element 22a is positioned on the -Y side with respect to the optical axis ax, and the second laser light-emitting element 22b is positioned on the +Y side with respect to the optical axis ax.

[0037] When viewed from above, multiple collimator lenses 23 are provided corresponding to multiple laser light-emitting elements 22. Each collimator lens 23 is positioned between each laser light-emitting element 22 and the light-transmitting member 25, parallelizing the excitation light E emitted from the corresponding laser light-emitting element 22. Each collimator lens 23 may be a spherical lens. Since spherical lenses have no orientation, the burden of ensuring mounting accuracy is reduced and mounting accuracy can be improved, so there is no need to enlarge the reflective member 26 by a margin to account for variations in mounting accuracy. Therefore, the reflective member 26 can be miniaturized. The collimator lens 23 may also be made of a diffractive lens. Since a diffractive lens is planar, the burden of ensuring mounting accuracy is reduced, and as described above, it can achieve the same effect as a spherical lens.

[0038] In this embodiment, the multiple collimator lenses 23 include a first collimator lens 23a corresponding to the first laser light-emitting element 22a and a second collimator lens 23b corresponding to the second laser light-emitting element 22b.

[0039] When viewed from above, the multiple reflective members 26 are arranged radially around the optical axis ax. Each reflective member 26 has a rectangular shape extending in a direction perpendicular to the optical axis ax. The multiple reflective members 26 are provided corresponding to the multiple laser light-emitting elements 22. Each reflective member 26 has a reflective surface and reflects light emitted from the corresponding laser light-emitting element 22 and parallelized by the collimator lens 23. In this embodiment, the multiple reflective members 26 include a first reflective member 26a corresponding to the first laser light-emitting element 22a and a second reflective member 26b corresponding to the second laser light-emitting element 22b. In this embodiment, the first reflective member 26a and the second reflective member 26b are separate from each other and are spaced apart.

[0040] Figure 4 is a cross-sectional view of the light source device 20. Figure 4 is a cross-section taken along the line IV-IV in Figure 3, and is a cross-sectional view of the light source device 20 taken from a plane that includes the optical axis ax and is perpendicular to the XY plane. Note that Figure 4 is a cross-sectional view including the first laser light source 22a and the second laser light source 22b among the multiple laser light source 22.

[0041] As shown in Figure 4, the base material 21 has a back surface 21a and a front surface 21b facing the opposite direction from the back surface 21a. The front surface 21b is located on the side of the translucent member 25 relative to the back surface 21a. The back surface 21a and the front surface 21b are parallel to each other, and the planar area of ​​the front surface 21b is smaller than the planar area of ​​the back surface 21a. The cross-section of the base material 21, defined by a plane containing the optical axis ax and perpendicular to the XY plane, is approximately mountain-shaped. Furthermore, the cross-sectional shape of the base material 21, defined by a plane containing the optical axis ax and perpendicular to the XY plane, is symmetrical to the shape shown in Figure 4 in the circumferential direction of the optical axis ax.

[0042] The substrate 21 has a first support portion 210 that supports a plurality of laser light-emitting elements 22, including a first laser light-emitting element 22a and a second laser light-emitting element 22b, and a second support portion 211 that supports a wavelength conversion element 24. Each laser light-emitting element 22 is thermally connected to the substrate 21 via a first support portion 210, and the wavelength conversion element 24 is thermally connected to the substrate 21 via a second support portion 211. In other words, the substrate 21 functions as a heat dissipation member that releases heat from the laser light-emitting elements 22 and the wavelength conversion element 24.

[0043] The first support section 210 includes an element support surface 210a that supports each laser light-emitting element 22, and a lens support surface 210b that supports each collimator lens 23. The element support surface 210a is a surface that is inclined with respect to the back surface 21a and the front surface 21b of the substrate 21. The element support surface 210a is a surface that is inclined in a direction approaching the optical axis ax from the back surface 21a side to the front surface 21b side. The lens support surface 210b is provided on the side of the element support surface 210a that is on the side of the light-transmitting member 25. The lens support surface 210b is a surface that is recessed toward the optical axis ax relative to the element support surface 210a and supports the collimator lens 23 via the lens holder 212.

[0044] The second support portion 211 is provided on the surface 21b that forms the top of the base material 21, which has a mountain-shaped form.

[0045] Next, the configuration of the laser light-emitting element 22 will be described. Each laser light-emitting element 22 has the same configuration. Figure 5 is a perspective view showing the configuration of the laser light-emitting element 22. As shown in Figure 5, each laser light-emitting element 22 includes a light-emitting section 220 and a submount 221. The light-emitting section 220 has a rectangular light-emitting surface 220a that emits excitation light (first light) E in the first wavelength band. The first wavelength band is, for example, a wavelength band from blue to violet, from 400 nm to 480 nm, with a peak wavelength of, for example, 455 nm.

[0046] The cross-section perpendicular to the principal ray of the excitation light E emitted from each laser light-emitting element 22 has an elliptical shape. The major axis of the ellipse coincides with the short side of the light-emitting surface 220a (the stacking direction of the light-emitting section 220 and the submount 221). Note that the cross-sectional shape of the excitation light E emitted from each laser light-emitting element 22 does not have to be a perfect ellipse.

[0047] The submount 221 is made of a ceramic material such as aluminum nitride or alumina. The submount 221 relieves thermal stress caused by the difference in the coefficient of linear expansion between the base material 21 and the light-emitting part 220. The submount 221 is joined to the first support part 210 of the base material 21 by a bonding material such as silver solder or gold-tin solder.

[0048] Based on this configuration, each laser light-emitting element 22 emits excitation light E toward the translucent member 25. Since the excitation light E emitted from each laser light-emitting element 22 behaves the same way in the translucent member 25, the behavior of the excitation light E emitted from the first laser light-emitting element 22a will be used as an example in the following explanation.

[0049] As shown in Figure 4, the excitation light E emitted from the first laser light-emitting element 22a is incident on the corresponding first collimator lens 23a. The first collimator lens 23a parallelizes the excitation light E. The excitation light E parallelized by the first collimator lens 23a is incident on the light-transmitting member 25.

[0050] The translucent member 25 has a first surface 25a and a second surface 25b. The first surface 25a of the translucent member 25 is the surface facing the substrate 21. The second surface 25b of the translucent member 25 is the surface opposite to the first surface 25a and is a light emission surface that emits light from the wavelength conversion element 24. The translucent member 25 is positioned on the opposite side of the wavelength conversion element 24 from the substrate 21, and the excitation light E emitted from the first laser light-emitting element 22a is incident on the first surface 25a. The translucent member 25 and the wavelength conversion element 24 may be in contact, or a gap may be provided. In this embodiment, by bringing the translucent member 25 and the wavelength conversion element 24 into contact, heat from the wavelength conversion element 24 can be released through the translucent member 25. When the translucent member 25 and the wavelength conversion element 24 are in contact, it is desirable that the translucent member 25 be made of a highly thermally conductive material such as sapphire.

[0051] The excitation light E emitted from the first laser light-emitting element 22a is refracted and incident from the first surface 25a, passes through the interior of the translucent member 25, and is incident on the first reflecting member 26a located on the second surface 25b. The first reflecting member 26a reflects the excitation light E emitted from the first laser light-emitting element 22a toward the wavelength conversion element 24.

[0052] Here, as shown in Figure 5, the cross-section of the excitation light E is elliptical, so the excitation light E forms an elliptical irradiation spot on the reflecting member 26. In this embodiment, since the excitation light E is incident on the reflecting member 26 from an oblique direction, an even more elongated elliptical irradiation spot is formed on the reflecting member 26.

[0053] In the light source device 20 of this embodiment, each reflective member 26 is provided on the second surface 25b of the light-transmitting member 25 in the incident region of the excitation light E emitted from the corresponding laser light-emitting element 22.

[0054] Figure 6 shows the irradiation spot of excitation light formed on the first reflective member. As shown in Figure 6, the planar shape of the first reflective member 26a is rectangular with a long side 26L and a short side 26S, and an elliptical irradiation spot SP is formed on the first reflective member 26a by the excitation light E. In this embodiment, the first laser light-emitting element 22a and the first reflective member 26a are arranged such that the long axis SP1 of the irradiation spot SP is aligned with the long side 26L of the first reflective member 26a. In other words, the first reflective member 26a is provided on the second surface 25b of the translucent member 25 corresponding to the irradiation spot SP of the excitation light E emitted from the corresponding first laser light-emitting element 22a. Therefore, the irradiation spot SP is less likely to extend beyond the first reflective member 26a, and the first reflective member 26a can efficiently incident the excitation light E onto the wavelength conversion element 24. Note that the planar shape of each reflective member refers to the planar shape of the reflective surface when the reflective member is viewed from a direction perpendicular to the reflective surface of each reflective member.

[0055] Although Figure 6 uses the first reflective member 26a as an example, the same can be said for the irradiation spot formed on the second reflective member 26b by the excitation light E emitted from the second laser light-emitting element 22b, and for the relationship between the laser light-emitting element 22 and the reflective member 26, which are in a corresponding relationship with each other.

[0056] In the light source device 20 of this embodiment, the reflective members 26 can be selectively placed on the second surface 25b of the light-transmitting member 25 in the region into which the excitation light E emitted from each laser light-emitting element 22 is incident.

[0057] It is preferable that each reflective member 26 has wavelength characteristics that selectively reflect the wavelength band of the excitation light E. In this embodiment, each reflective member 26 is composed of a dichroic mirror (optical element) 126 that reflects the excitation light E in the first wavelength band and transmits the fluorescence YL in the second wavelength band. Furthermore, it is preferable that each reflective member 26 has incidence angle characteristics in which it has a relatively high reflectivity with respect to the incidence angle of the excitation light E and a relatively low reflectivity with respect to other incidence angles.

[0058] The wavelength conversion element 24 has an incident surface 24a to which the excitation light E is incident, and a back surface 24b opposite to the incident surface 24a. The back surface 24b of the wavelength conversion element 24 is supported by a second support portion 211 of the base material 21. A reflective mirror 29 is provided between the back surface 24b of the wavelength conversion element 24 and the second support portion 211 (front surface 21b).

[0059] The wavelength conversion element 24 includes a phosphor that converts excitation light E into fluorescence (second light) YL in a second wavelength band different from the first wavelength band. The second wavelength band is, for example, the yellow wavelength band of 550 to 640 nm. As such a phosphor, for example, a YAG (yttrium aluminum garnet) phosphor can be used. The phosphor-forming material may be one type, or a mixture of particles formed using two or more types of materials may be used as the phosphor.

[0060] The wavelength conversion element 24 emits both the wavelength-converted fluorescent YL and the unconverted excitation light E from the incident surface 24a. The unconverted excitation light E includes not only the component that was not converted to fluorescence within the phosphor but also the component reflected from the surface of the wavelength conversion element 24.

[0061] In the wavelength conversion element 24, a portion of the excitation light E and fluorescence YL travel toward the back surface 24b. In this embodiment, the fluorescence YL and excitation light E can be reflected toward the incident surface 24a by the reflection mirror 29 provided between the back surface 24b and the second support portion 211. Based on this configuration, the wavelength conversion element 24 of this embodiment can emit white illumination light WL from the incident surface 24a, which includes a portion of the excitation light E and the fluorescence YL.

[0062] The illumination light WL emitted from the wavelength conversion element 24 passes through the light-transmitting member 25 and is incident on the light-collecting optical element 27. A portion of the illumination light WL is incident on each reflective member 26 formed on the second surface 25b of the light-transmitting member 25. Each reflective member 26 is composed of a dichroic mirror 126 that transmits the fluorescent YL and reflects the excitation light E, so it transmits the fluorescent YL contained in the illumination light WL and reflects the excitation light E contained in the illumination light WL.

[0063] In the light source device 20 of this embodiment, the reflective member 26 is selectively positioned on the second surface 25b of the light-transmitting member 25 at the position where the excitation light E is incident (irradiation spot SP). Therefore, the region where the excitation light E is not incident has light transmittance regardless of the wavelength band. Therefore, the excitation light E contained in the illumination light WL is emitted from the gaps between the multiple reflective members 26 toward the focusing optical element 27. The gaps between the reflective members 26 refer to the gaps between adjacent reflective members 26 in the circumferential direction of the optical axis ax, and between a pair of reflective members 26 facing each other across the optical axis ax. In the light source device 20 of this embodiment, the amount of loss of excitation light E due to reflection by the reflective members 26 can be reduced, so that white illumination light WL can be generated efficiently.

[0064] The light-gathering optical element 27 is positioned on the side of the second surface 25b of the light-transmitting member 25 and narrows the light beam width by focusing the illumination light WL emitted from the wavelength conversion element 24 and transmitted through the light-transmitting member 25. In this embodiment, the light-gathering optical element 27 may be provided in contact with the second surface 25b of the light-transmitting member 25, or it may be provided in a non-contact state. The light-gathering optical element 27 in this embodiment is composed of a meniscus lens including a light-entering surface consisting of a concave surface and a light-exiting surface consisting of a convex surface. Note that the light-gathering optical element 27 does not have to be a meniscus lens.

[0065] Of the illumination light WL emitted from the wavelength conversion element 24, the fluorescent YL is emitted at a large radiation angle. In order to efficiently collect the fluorescent YL emitted at a large radiation angle and transmit it to the subsequent optical system, it is necessary to position the lens into which the fluorescent YL emitted from the wavelength conversion element 24 enters close to the wavelength conversion element 24.

[0066] Here, the effects of the light source device 20 of this embodiment will be explained by comparing it with a light source device in which the light-transmitting member 25 is omitted and the wavelength conversion element 24 and the light-gathering optical element 27 are arranged in close proximity. In the configuration of the comparative example light source device, the method of injecting excitation light into the wavelength conversion element 24 is not considered in order to simplify the explanation.

[0067] Figure 7A shows how fluorescent yellow light (YL) is incident on the condensing optical element 27 in the light source device 20A of the first comparative example. Figure 7B shows how fluorescent yellow light (YL) is incident on the condensing optical element 27 in the light source device 20 of this embodiment. In the light source device 20A of the first comparative example shown in Figure 7A, since a light-transmitting member 25 is not provided, the focusing optical element 27 can be placed in close proximity to the wavelength conversion element 24. Therefore, in the light source device 20A, the fluorescence Y emitted from the wavelength conversion element 24 at a large radiation angle α can be focused by the focusing optical element 27 and incorporated into the subsequent optical system. In the light source device 20A of the first comparative example shown in Figure 7A, the distance from the incident surface 24a of the wavelength conversion element 24 to the focusing optical element 27 is defined as H0.

[0068] On the other hand, in the light source device 20 of this embodiment shown in Figure 7B, a translucent member 25 is placed between the wavelength conversion element 24 and the focusing optical element 27. Here, let H1 be the thickness of the translucent member 25. Comparing the thickness H1 of the translucent member 25 with the distance H0 from the incident surface 24a of the wavelength conversion element 24 to the end face 27a of the focusing optical element 27 that is closest to the wavelength conversion element 24 in the light source device 20A of the first comparative example, we find that H1 > H0. Since the refractive index of the translucent member 25 is greater than 1, the air-equivalent length of the thickness H1 is smaller than the actual dimension of the thickness H1. For this reason, the air-equivalent length of the thickness H1 can be considered to be approximately equal to the distance H0 of the comparative example. In other words, light with an emission angle α in air behaves as light with a small emission angle β in the translucent member 25.

[0069] Therefore, according to the light source device 20 of this embodiment, by suppressing the spreading of fluorescent YL with the light-transmitting member 25, fluorescent YL emitted in the air at a radiation angle α can be captured by the light-collecting optical element 27, as in the light source device 20A of the first comparative example. Thus, in the light source device 20 of this embodiment, even when the light-transmitting member 25 is placed between the wavelength conversion element 24 and the light-collecting optical element 27, the same utilization efficiency of fluorescent YL as when the wavelength conversion element 24 and the light-collecting optical element 27 are placed in close proximity can be achieved.

[0070] In the light source device 20 of this embodiment, as shown in Figure 4, the first distance D1 along the optical axis 27C of the focusing optical element 27 between the wavelength conversion element 24 and the focusing optical element 27 is made smaller than the second distance D2 along the optical axis 27C between the first laser light-emitting element 22a and the focusing optical element 27. The optical axis 27C of the focusing optical element 27 is an axis along the Z axis and coincides with the optical axis ax of the light source device 20. In this embodiment, the first distance D1 is defined as the distance from the incident surface 24a of the wavelength conversion element 24 to the end face 27a of the focusing optical element 27 that is closest to the wavelength conversion element 24. The second distance D2 is defined as the distance from the center of the light-emitting surface 220a of the first laser light-emitting element 22a to the end face 27a of the focusing optical element 27.

[0071] Here, we will explain the effect of the light source device 20 of this embodiment by making the first distance D1 larger than the second distance D2, by comparing it with the light source device of the comparative example in which the second distance D2 is larger than the first distance D1.

[0072] Figure 8A shows how fluorescent yellow light (YL) is incident on the focusing optical element 27 in the light source device 20B of the second comparative example. Figure 8B shows how fluorescent yellow light (YL) is incident on the focusing optical element 27 in the light source device 20C of the third comparative example.

[0073] As shown in Figure 8A, the light source device 20B of the second comparative example differs from the configuration of the light source device 20 of this embodiment in that the second support portion 211 supporting the wavelength conversion element 24 is provided in a recess formed on the top of the substrate 21. In the light source device 20B of the second comparative example, since the laser light-emitting element 22 is positioned between the wavelength conversion element 24 and the focusing optical element 27, the first distance D1 becomes larger than the second distance D2.

[0074] Therefore, among the fluorescent YL emitted from the wavelength conversion element 24 at an emission angle α, components with a large angle cannot be captured by the focusing optical element 27. In other words, in the light source device 20B of the second comparative example, only fluorescent YL with an emission angle γ narrower than the emission angle α can be captured by the focusing optical element 27, resulting in a lower light utilization efficiency of fluorescent YL compared to the light source device 20 of this embodiment. Furthermore, the light of components that are not captured by the focusing optical element 27 may be absorbed by other optical components in the device, potentially generating unwanted heat.

[0075] As shown in Figure 8B, the light source device 20C of the third comparative example differs from the configuration of the light source device 20 of this embodiment in that it does not use a light-transmitting member 25, and instead directly incidents excitation light E from the surroundings onto a wavelength conversion element 24 placed in the center of the substrate 21. Furthermore, in the light source device 20C of the third comparative example, the light-emitting surface 220a of the laser light-emitting element 22 is positioned closer to the focusing optical element 27 than the support surface of the wavelength conversion element 24. Therefore, in the light source device 20C of the third comparative example, the laser light-emitting element 22 is positioned between the wavelength conversion element 24 and the focusing optical element 27, so, similar to the light source device 20B of the second comparative example, the first distance D1 is greater than the second distance D2.

[0076] Therefore, in the third comparative example, the light source device 20C can only capture fluorescent YL with a radiation angle ε narrower than the radiation angle α into the focusing optical element 27, resulting in a lower light utilization efficiency of fluorescent YL compared to the light source device 20 of this embodiment. In reality, however, in the light source device 20C, light with a radiation angle α is blocked by the substrate 21 and cannot be captured by the focusing optical element 27.

[0077] In this embodiment, the light source device 20 makes the first distance D1 smaller than the second distance D2, allowing the fluorescent YL emitted from the wavelength conversion element 24 at a large radiation angle to be efficiently captured by the focusing optical element 27. The focusing optical element 27 reduces the luminous beam width by focusing the illumination light WL containing the fluorescent YL.

[0078] In this manner, the light source device 20 of this embodiment emits illumination light WL focused by the light-gathering optical element 27. The illumination light WL emitted from the light source device 20 is incident on the pickup optical system 34. The illumination light WL, whose beam width has been narrowed by being focused by the light-gathering optical element 27, is incident on the pickup optical system 34 smoothly.

[0079] The light source device 20 according to this embodiment described above provides the following effects. The light source device 20 of this embodiment includes a base material 21 having a plurality of laser light-emitting elements 22 including a first laser light-emitting element 22a that emits excitation light E in the blue wavelength band, a wavelength conversion element 24 that converts the excitation light E into fluorescence YL in the yellow wavelength band which is different from the blue wavelength band, a first support part 210 that supports the plurality of laser light-emitting elements 22, and a second support part 211 that supports the wavelength conversion element 24, and a first surface 25a and a second surface 25b, and on the side opposite to the base material 21 with respect to the wavelength conversion element 24 The device comprises a translucent member 25 on which excitation light E emitted from multiple laser light-emitting elements 22 is incident on a first surface 25a; a reflective member 26 including a first reflective member 26a positioned on the second surface 25b of the translucent member 25 and reflecting excitation light E emitted from the first laser light-emitting element 22a toward the wavelength conversion element 24; and a focusing optical element 27 positioned on the side of the second surface 25b of the translucent member 25 and focusing illumination light WL emitted from the wavelength conversion element 24 and transmitted through the translucent member 25. The first distance D1 between the wavelength conversion element 24 and the focusing optical element 27 along the optical axis 27C of the focusing optical element 27 is smaller than the second distance D2 between the first laser light-emitting element 22a and the focusing optical element 27 along the optical axis 27C.

[0080] According to the light source device 20 of this embodiment, the light-transmitting member 25 placed between the wavelength conversion element 24 and the focusing optical element 27 allows the fluorescent YL to be efficiently captured by the focusing optical element 27 while suppressing its spreading. Furthermore, in the light source device 20 of this embodiment, the excitation light E reflected by the reflective member 26 arranged on the second surface 25b of the light-transmitting member 25 is incident on the wavelength conversion element 24, allowing the wavelength conversion element 24 to be positioned closer to the focusing optical element 27 than the laser light-emitting element 22. Therefore, by making the first distance D1 smaller than the second distance D2, the focusing optical element 27 can efficiently capture the fluorescent YL emitted from the wavelength conversion element 24 at a large radiation angle. Therefore, the light source device 20 of this embodiment can generate bright illumination light WL by efficiently extracting fluorescent YL. Furthermore, the light source device 20 of this embodiment can generate white illumination light WL on its own without the need to separately prepare a blue light source, thus enabling a miniaturization of the device configuration.

[0081] The light source device 20 of this embodiment further includes a collimator lens 23 positioned between a plurality of laser light-emitting elements 22 and a light-transmitting member 25, which parallelizes the excitation light E emitted from each laser light-emitting element 22.

[0082] With this configuration, the spread of the excitation light E is suppressed by parallelizing the excitation light E, so that the excitation light E can be efficiently incident onto the wavelength conversion element 24 even when the distance between each laser light-emitting element 22 and the wavelength conversion element 24 is increased. As a result, the loss component of the excitation light E is suppressed, and the degree of freedom in arranging the wavelength conversion element 24 and each laser light-emitting element 22 on the substrate 21 is increased. Furthermore, by increasing the distance between the laser light-emitting element 22 and the wavelength conversion element 24, which act as heat sources in the light source device 20, the thermal density of the substrate 21 is reduced. This makes it easier to control the temperature of each laser light-emitting element 22 and wavelength conversion element 24, and for example, the output of the excitation light E can be increased by increasing the number of laser light-emitting elements 22 to compensate for the reduction in thermal density.

[0083] In the light source device 20 of this embodiment, each reflective member 26 is composed of a dichroic mirror 126 that reflects the excitation light E and transmits the fluorescence YL.

[0084] This configuration makes it possible to prevent losses caused by the reflection of fluorescent YL by the reflective member 26.

[0085] In the light source device 20 of this embodiment, the multiple reflective members 26 are separate from each other and are arranged spaced apart.

[0086] With this configuration, each reflective member 26 can be positioned at a predetermined location on the second surface 25b of the light-transmitting member.

[0087] In the light source device 20 of this embodiment, each reflective member 26 is provided on the second surface 25b of the light-transmitting member 25 corresponding to the incident region of the excitation light E emitted from the corresponding laser light-emitting element 22. In this embodiment, the planar shape of each reflective member 26 is rectangular with a longitudinal side 26L and a transverse side 26S, and the excitation light E forms an elliptical irradiation spot SP on each reflective member 26, and the corresponding laser light-emitting element 22 and reflective member 26 are arranged such that the longitudinal axis SP1 of the irradiation spot SP is aligned with the longitudinal side 26L of the reflective member 26.

[0088] With this configuration, the reflective members 26 are selectively positioned on the second surface 25b of the translucent member 25 at the location where the excitation light E is incident (irradiation spot SP). This makes it difficult for the irradiation spot SP to extend beyond each reflective member 26, allowing the excitation light E reflected by the reflective members 26 to be efficiently incident onto the wavelength conversion element 24. Furthermore, since no reflective members 26 are placed in the region of the second surface 25b of the translucent member where excitation light E does not occur, the excitation light E contained in the illumination light WL can be extracted from the gaps between each reflective member 26 toward the focusing optical element 27. Therefore, by reducing the loss of excitation light E due to the reflective member 26, a portion of the excitation light E can be used as illumination light WL.

[0089] The projector 1 according to this embodiment described above provides the following effects. The projector 1 of this embodiment comprises a light source device 20, light modulators 4B, 4G, and 4R that form image light by modulating blue light LB, green light LG, and red light LR from the light source device 20, and a projection optical device 6 that projects the aforementioned image light.

[0090] According to the projector 1 of this embodiment, since it is equipped with a small light source device 20 that generates bright white illumination light WL, it can form and project high-brightness images despite its small size.

[0091] (Second Embodiment) Next, the configuration of the light source device according to the second embodiment of the present invention will be described. In this embodiment, components or parts common to the first embodiment are denoted by the same reference numerals, and their details will not be described.

[0092] Figure 9 is a cross-sectional view showing the main components of the light source device of this embodiment. Figure 9 is a cross-sectional view corresponding to Figure 4 of the first embodiment. As shown in Figure 9, the light source device 120 of this embodiment further includes a diffusion section 30. The diffusion section 30 diffuses the excitation light E emitted from each laser light-emitting element 22. The diffusion section 30 is positioned in the optical path of the excitation light E from the light-emitting surface 220a of each laser light-emitting element 22 to the incident surface 24a of the wavelength conversion element 24.

[0093] In this embodiment, the diffusion portion 30 is formed in the region where each reflective member 26 is arranged on the second surface 25b of the translucent member 25 facing the light-collecting optical element 27. The diffusion portion 30 is composed of an uneven shape 30a formed on the second surface 25b. The uneven shape 30a is formed, for example, by creating random irregularities on the second surface 25b using means such as sandblasting, or by forming a pattern having an optical diffusion function such as a holographic diffusion element on the second surface 25b.

[0094] In the light source device 120 of this embodiment, when the excitation light E emitted from each laser light-emitting element 22 is incident on each reflecting member 26, it passes through the uneven shape 30a of the diffusion section 30 and is diffused as shown by the dashed line. As a result, the intensity distribution within the cross-section of the light beam of the excitation light E diffused by the diffusion section 30 is made uniform, and the light density of the irradiation spot formed by the excitation light E on the incident surface 24a of the wavelength conversion element 24 can be made uniform. Therefore, localized heat generation of the wavelength conversion element 24 is suppressed, which increases the fluorescence conversion efficiency and extends the lifespan of the wavelength conversion element 24.

[0095] In this embodiment, we have given an example in which a diffusion portion 30 is formed on the second surface 25b of the translucent member 25 on which each reflective member 26 is arranged, but the position of the diffusion portion 30 is not limited to this. For example, a diffusion portion 30A may be formed in the region of the first surface 25a of the translucent member 25 to which the excitation light E emitted from each laser light-emitting element 22 is incident, as shown by the dashed line in Figure 9. Alternatively, a diffusion plate placed on the optical path of the excitation light E between the laser light-emitting element 22 and the first surface 25a of the translucent member 25 may be used as the diffusion portion. Note that both the diffusion portion 30A on the first surface 25a and the diffusion portion 30 on the second surface 25b may be formed.

[0096] (Third embodiment) Next, the configuration of the light source device according to the third embodiment of the present invention will be described. In this embodiment, components or parts common to the first embodiment are denoted by the same reference numerals, and their details will not be described.

[0097] Figure 10 is a cross-sectional view showing the main part of the light source device of this embodiment. Figure 10 is a cross-sectional view corresponding to Figure 4 of the first embodiment. As shown in Figure 10, the light source device 121 of this embodiment further includes an opposing reflective member (third reflective member) 31.

[0098] The opposing reflective members 31 are positioned on the wavelength conversion element 24 side relative to the light-transmitting member 25, and have a reflective surface that reflects the excitation light E reflected by each reflective member 26 back to each reflective member 26. Each reflective member 26 reflects the excitation light E reflected by the opposing reflective member 31 toward the wavelength conversion element 24. The opposing reflective members 31 are made of, for example, a dielectric multilayer film or a metal film.

[0099] In this embodiment, the opposing reflective member 31 is provided in a region of the first surface 25a of the translucent member 25 where excitation light E does not occur, and which faces each reflective member 26 and does not interfere with the wavelength conversion element 24. Alternatively, the opposing reflective member 31 may be formed on the second support portion 211 of the base material 21 instead of the first surface 25a of the translucent member.

[0100] In the light source device 121 of this embodiment, the excitation light E emitted from each laser light-emitting element 22 is incident on the wavelength conversion element 24 by having its optical path bent three times between the reflecting member 26 and the opposing reflecting member 31. By increasing the number of times the optical path of the excitation light E is bent, the distance between the wavelength conversion element 24 and each laser light-emitting element 22, and the distance between each laser light-emitting element 22, can be extended in the direction perpendicular to the optical axis 27C of the focusing optical element 27. As a result, the thermal density of the substrate 21 is suppressed, which can improve the wavelength conversion efficiency of the wavelength conversion element 24 and extend the lifespan of the wavelength conversion element 24. Furthermore, for example, the output of the excitation light E can be increased by increasing the number of laser light-emitting elements 22 to compensate for the decrease in thermal density.

[0101] (Fourth Embodiment) Next, the configuration of the light source device according to the fourth embodiment of the present invention will be described. In this embodiment, components or parts common to the first embodiment are denoted by the same reference numerals, and their details will not be described.

[0102] Figure 11 is a cross-sectional view of the light source device of this embodiment. Figure 11 is a cross-sectional view corresponding to Figure 4 of the first embodiment. As shown in Figure 11, the light source device 122 of this embodiment comprises a base material 215, a plurality of laser light-emitting elements 22, a plurality of collimator lenses 23, a wavelength conversion element 24, a light-transmitting member 25, a plurality of reflective members 26, a light-gathering optical element 27, and a side plate portion 28.

[0103] The base material 215 of this embodiment has a heat insulating wall 216 formed between the first support portion 210 and the second support portion 211. The heat insulating wall 216 is a groove portion 216a formed in the base material 21. When viewed from a plan view from the direction of the optical axis 27C of the light-gathering optical element 27, the heat insulating wall 216 is arranged to surround the second support portion 211 that supports the wavelength conversion element 24.

[0104] In the light source device 122 of this embodiment, the heat H of the laser light-emitting element 22 and the wavelength conversion element 24 is separated within the substrate 21 by the groove 216a which functions as an insulating wall 216. This prevents the heat density of the substrate 21 from increasing due to the heat of the laser light-emitting element 22 and the wavelength conversion element 24 influencing each other. For example, if the temperature rise of the wavelength conversion element 24 due to the heat of the laser light-emitting element 22 can be suppressed, effects such as improved fluorescence conversion efficiency and increased reliability of the wavelength conversion element 24 can be obtained. On the other hand, if the temperature rise of the laser light-emitting element 22 due to the heat of the wavelength conversion element 24 can be suppressed, effects such as improved efficiency and increased reliability of the laser light-emitting element 22 can be obtained.

[0105] In this embodiment, we have given an example in which the groove 216a formed in the base material 21 is used as the insulating wall 216, but the method of constructing the insulating wall is not limited to this. Figure 12 shows the configuration of an insulating wall in a modified example. As shown in Figure 12, the insulating wall 218 may be composed of insulating material 218a embedded inside the base material 21 between the first support portion 210 and the second support portion 211. According to this modified configuration, the function of the insulating wall 218 can be further enhanced by the insulating material 218a embedded inside the base material 21.

[0106] Although one embodiment of the present invention has been described as an example, the present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0107] For example, in the above embodiment, a case was given in which multiple reflective members 26 are arranged on the second surface 25b of the light-transmitting member 25, but a single reflective member may be arranged on the second surface 25b of the light-transmitting member 25.

[0108] Figure 13 shows the shape of the reflective member in a modified example. The reflective member 260 shown in Figure 13 has a ring-shaped planar form. That is, in the light source device 123 of this modified example, the first reflective member corresponding to the first laser light-emitting element 22a and the second reflective member corresponding to the second laser light-emitting element 22b are formed integrally.

[0109] According to the configuration of this modified example, since the reflective member 260 is composed of a single member, even if the position of the irradiation spot SP of the excitation light E shifts due to errors when mounting each laser light-emitting element 22 on the substrate 21, the excitation light E can be incident on the wavelength conversion element 24 without loss. In the case of using a ring-shaped reflective member 260, there is a risk that the amount of excitation light E incident on the focusing optical element 27 will decrease, but it is possible to compensate for the amount of excitation light E by methods such as increasing the reflectivity of the incident surface 24a of the wavelength conversion element 24 or adjusting the fluorescence conversion efficiency by changing the composition of the wavelength conversion element 24.

[0110] Furthermore, although the above embodiment and modified light source devices were given as examples of having multiple laser light-emitting elements 22, the number of laser light-emitting elements 22 is not limited, and may consist only of the first laser light-emitting element 22a.

[0111] Furthermore, although the above embodiment illustrates a projector 1 equipped with three optical modulators 4R, 4G, and 4B, it is also possible to apply this to a projector that displays color images with a single optical modulator. Moreover, the optical modulator is not limited to the liquid crystal panel described above; for example, a digital mirror device can also be used.

[0112] Furthermore, while the above embodiment shows an example of applying the light source device according to the present invention to a projector, it is not limited to this. The light source device according to the present invention can also be applied to lighting fixtures such as automobile headlights.

[0113] A light source device according to an embodiment of the present invention may have the following configuration. A light source device according to one aspect of the present invention comprises: a substrate having a first laser light-emitting element that emits first light in a first wavelength band; a wavelength conversion element that converts the first light into second light in a second wavelength band different from the first wavelength band; a first support part that supports the first laser light-emitting element; and a second support part that supports the wavelength conversion element; a translucent member having a first surface and a second surface opposite to the first surface, and positioned on the opposite side of the substrate from the wavelength conversion element, to which the first light emitted from the first laser light-emitting element is incident; a first reflective member positioned on the second surface of the translucent member that reflects the first light emitted from the first laser light-emitting element toward the wavelength conversion element; and a focusing optical element positioned on the side of the second surface of the translucent member that focuses the light emitted from the wavelength conversion element and transmitted through the translucent member, wherein the first distance along the optical axis of the focusing optical element between the wavelength conversion element and the focusing optical element is smaller than the second distance along the optical axis between the first laser light-emitting element and the focusing optical element.

[0114] In one embodiment of the present invention, a light source device may further include a diffusion unit that diffuses the first light, wherein the diffusion unit is arranged in the optical path of the first light from the light-emitting surface of the first laser light-emitting element to the incident surface of the wavelength conversion element.

[0115] In one embodiment of the present invention, the light source device may be configured such that the diffusion portion is formed in the region on the second surface of the light-transmitting member where the first reflective member is arranged.

[0116] In one embodiment of the present invention, the first surface of the light-transmitting member faces the wavelength conversion element, and the diffusion portion is formed in the region of the first surface of the light-transmitting member to which the first light emitted from the first laser light-emitting element is incident.

[0117] In one embodiment of the present invention, a light source device may further include a third reflective member positioned on the wavelength conversion element side with respect to the light-transmitting member, which reflects the first light reflected by the first reflective member back to the first reflective member, and the first reflective member may reflect the first light reflected by the third reflective member toward the wavelength conversion element.

[0118] In a light source device according to one aspect of the present invention, the substrate may have a configuration in which a heat insulating wall is provided between a first support portion and a second support portion.

[0119] In one embodiment of the present invention, the heat insulating wall may be configured as a groove formed in the substrate.

[0120] In one embodiment of the present invention, the insulating wall may be an insulating material embedded in the substrate.

[0121] In one embodiment of the present invention, a light source device may further include a parallelizing lens disposed between a first laser light-emitting element and a light-transmitting member, which parallelizes the first light emitted from the first laser light-emitting element.

[0122] In a light source device according to one aspect of the present invention, the first reflective member may be configured to be an optical element that reflects first light and transmits second light.

[0123] In one embodiment of the present invention, a light source device further comprises a second laser light-emitting element that emits first light, and a second reflecting element disposed on the second surface of a light-transmitting member that reflects the first light emitted from the second laser light-emitting element toward a wavelength conversion element, wherein the first reflecting element and the second reflecting element are separate from each other and are spaced apart.

[0124] In a light source device according to one aspect of the present invention, the first reflective member may be provided on the second surface of the translucent member corresponding to the incident region of the first light emitted from the first laser light-emitting element, and the second reflective member may be provided on the second surface of the translucent member corresponding to the incident region of the first light emitted from the second laser light-emitting element.

[0125] In a light source device according to one aspect of the present invention, the planar shapes of the first reflective member and the second reflective member are rectangular, each having a long side and a short side; the first light emitted from the first laser light-emitting element forms an elliptical first irradiation spot on the first reflective member; the first light emitted from the second laser light-emitting element forms an elliptical second irradiation spot on the second reflective member; the first laser light-emitting element and the first reflective member are arranged such that the long axis of the first irradiation spot is aligned with the long side of the first reflective member; and the second laser light-emitting element and the second reflective member are arranged such that the long axis of the second irradiation spot is aligned with the long side of the first reflective member.

[0126] In one embodiment of the present invention, a light source device further comprises a second laser light-emitting element that emits first light, and a second reflecting element disposed on the second surface of a light-transmitting member that reflects the first light emitted from the second laser light-emitting element toward a wavelength conversion element, wherein the first reflecting element and the second reflecting element are integrally formed.

[0127] A projector according to one aspect of the present invention may have the following configuration. A projector according to one aspect of the present invention comprises a light source device according to the above aspect of the present invention, an optical modulator for modulating light from the light source device, and a projection optical device for projecting light modulated by the optical modulator. [Explanation of symbols]

[0128] 1…Projector, 4B,4G,4R…Optical Modulator, 6…Projection Optical Device, 20,20A,20B,20C,120,121,122,123…Light Source Device, 21,215…Substrate, 22…Laser Light-Emitting Device, 22a…First Laser Light-Emitting Device, 22b…Second Laser Light-Emitting Device, 23…Collimator Lens (Parallelizing Lens), 24…Wavelength Conversion Element, 24a…Incident Surface, 25…Transparent Material, 25a…First Surface, 25b…Second Surface, 26,260…Reflective Material, 26a…First Reflective Material, 26b… Second reflective member, 26L...long side, 26S...short side, 27...light-gathering optical element, 27C,ax...optical axis, 30,30A...diffusing part, 31...opposing reflective member (third reflective member), 126...dichroic mirror (optical element), 210...first support part, 211...second support part, 216,218...insulating wall, 216a...groove part, 218a...insulating material, 220a...light-emitting surface, D1...first distance, D2...second distance, E...excitation light (first light), H...heat, H0...distance, SP...irradiation spot, SP1...long axis, YL...fluorescence (second light).

Claims

1. A first laser light-emitting element that emits first light in the first wavelength band, A wavelength conversion element that converts the first light into a second light in a second wavelength band different from the first wavelength band, A substrate having a first support portion for supporting the first laser light-emitting element and a second support portion for supporting the wavelength conversion element, A light-transmitting member having a first surface and a second surface opposite to the first surface, and positioned on the opposite side of the substrate from the wavelength conversion element, wherein the first light emitted from the first laser light-emitting element is incident on the first surface, A first reflective member is disposed on the second surface of the light-transmitting member and reflects the first light emitted from the first laser light-emitting element toward the wavelength conversion element, A light-gathering optical element is disposed on the second surface side of the light-transmitting member and collects light emitted from the wavelength conversion element and transmitted through the light-transmitting member, The light-transmitting member is positioned on the wavelength conversion element side, and a third reflective member is provided to reflect the first light reflected by the first reflective member back to the first reflective member. The first distance between the wavelength conversion element and the focusing optical element along the optical axis of the focusing optical element is smaller than the second distance between the first laser light-emitting element and the focusing optical element along the optical axis. The first reflective member reflects the first light reflected by the third reflective member toward the wavelength conversion element. A light source device characterized by the following features.

2. The device further comprises a diffusing section that diffuses the first light, The diffusion portion is arranged in the optical path of the first light from the light-emitting surface of the first laser light-emitting element to the incident surface of the wavelength conversion element. The light source device according to feature 1.

3. The diffusion portion is formed in the region on the second surface of the light-transmitting member where the first reflective member is arranged. The light source device according to claim 2.

4. The first surface of the light-transmitting member faces the wavelength conversion element, The diffusion portion is formed in the region of the first surface of the light-transmitting member to which the first light emitted from the first laser light-emitting element is incident. The light source device according to claim 2 or 3, characterized by the features described above.

5. The substrate has an insulating wall provided between the first support portion and the second support portion. A light source device according to any one of claims 1 to 4.

6. The aforementioned insulating wall is a groove formed in the substrate. The light source device according to claim 5.

7. The aforementioned insulating wall is an insulating material embedded in the substrate. The light source device according to claim 6.

8. The system further comprises a parallelizing lens disposed between the first laser light-emitting element and the light-transmitting member, which parallelizes the first light emitted from the first laser light-emitting element. A light source device according to any one of claims 1 to 7, characterized by the features described above.

9. The first reflective member is composed of an optical element that reflects the first light and transmits the second light. A light source device according to any one of claims 1 to 8.

10. The second laser light-emitting element that emits the first light, The light-transmitting member further comprises a second reflective member disposed on the second surface of the light-transmitting member, which reflects the first light emitted from the second laser light-emitting element toward the wavelength conversion element, The first reflective member and the second reflective member are separate entities and are arranged spaced apart from each other. A light source device according to any one of claims 1 to 9, characterized by the following:

11. The first reflective member is provided on the second surface of the translucent member corresponding to the incident region of the first light emitted from the first laser light-emitting element, The second reflective member is provided on the second surface of the translucent member corresponding to the incident region of the first light emitted from the second laser light-emitting element. The light source device according to feature 10.

12. The planar shapes of the first reflective member and the second reflective member are each rectangular, having a long side and a short side. The first light emitted from the first laser light-emitting element forms an elliptical first irradiation spot on the first reflecting member. The first light emitted from the second laser light-emitting element forms an elliptical second irradiation spot on the second reflective member. The first laser light-emitting element and the first reflecting member are arranged such that the long axis of the first irradiation spot is aligned with the long side of the first reflecting member. The second laser light-emitting element and the second reflecting member are arranged such that the long axis of the second irradiation spot is aligned with the long side of the second reflecting member. The light source device according to feature 11.

13. The second laser light-emitting element that emits the first light, The light-transmitting member further comprises a second reflective member disposed on the second surface of the light-transmitting member, which reflects the first light emitted from the second laser light-emitting element toward the wavelength conversion element, The first reflective member and the second reflective member are formed integrally. A light source device according to any one of claims 1 to 9, characterized by the following:

14. A light source device according to any one of claims 1 to 13, A light modulator that modulates the light from the aforementioned light source device, The system comprises a projection optical device that projects light modulated by the aforementioned optical modulation device, A projector characterized by the following features.

Images