Light source device and projector

Abstract

To provide a light source device, a projector, and a cooling plate that can improve cooling efficiency.SOLUTION: A light source device comprises: a light source module; a plurality of heat receiving plates that is connected with the light source module; and a cooling plate that is connected with the plurality of heat receiving plates and has cooling liquid circulating therein. The cooling plate includes an inflow part, an outflow part, an upstream side circulation part in which the cooling liquid flowing in from the inflow part circulates in a second direction orthogonal to a first direction, a downstream side circulation part in which the cooling liquid circulating in the upstream side circulation part circulates in a direction opposite to the second direction, and a plurality of heat transfer parts that is provided in at least one of the upstream side circulation part and the downstream side circulation part and is arranged side by side in the second direction. The plurality of heat transfer parts has a plurality of fins that extends in the second direction and is arranged in the first direction, and a plurality of channels that is provided between the plurality of fins. The plurality of heat receiving plates is arranged along the second direction. The plurality of heat transfer parts is separated from each other between the plurality of heat receiving plates in the second direction.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to a light source device and Projector To Regarding. [Background technology]

[0002] BACKGROUND ART Conventionally, a projector equipped with a light source device having a plurality of solid-state light sources is known (see, for example, Patent Document 1). In the projector described in Patent Document 1, the light source device includes a first light source and a second light source, each of which includes a light source array and a light source cooling unit that cools the light source array. The light source array includes a plurality of light source modules, and the plurality of light source modules are arranged side by side in the short side direction of each light source module. Each of the plurality of light source modules includes a plurality of solid-state light sources arranged vertically and horizontally, and a support unit that supports the plurality of solid-state light sources and is fixed to the light source cooling unit.

[0003] The light source cooling unit includes a first member to which the light source array is fixed, and a second member disposed on the opposite side of the first member from the light source array. The light source cooling unit is configured by combining the first member and the second member. The first member has a plurality of mounting portions to which the plurality of light source modules are attached. The first member also has a first fin and a second fin on the surface opposite to the surface on which the plurality of mounting portions are provided. The first fin and the second fin form part of a flow path through which the liquid coolant flows when the first member and the second member are combined. The liquid refrigerant flows between the multiple fin elements that form the first fin and between the multiple fin elements that form the second fin. Specifically, the liquid refrigerant that flows into the light-source cooling unit through the inflow portion is divided into a liquid refrigerant that flows on the first fin side and a liquid refrigerant that flows on the second fin side. The liquid refrigerant that flows on the first fin side flows between the multiple fin elements of the first fin while reversing its flow direction multiple times. Similarly, the liquid refrigerant that flows on the second fin side flows between the multiple fin elements of the second fin while reversing its flow direction multiple times. The liquid refrigerant that has flowed on the first fin side and the liquid refrigerant that has flowed on the second fin side are discharged to the outside of the light-source cooling unit through the outflow portion. That is, the light-source cooling unit has a serpentine flow path through which the liquid refrigerant flows from the inflow portion to the outflow portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-79950 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the light source device described in Patent Document 1 has a problem in that the fin elements are relatively long in the extension direction, resulting in large pressure loss of the coolant. Also, in the light source cooling section that divides the liquid coolant that flows in from the inlet section and circulates it between the first fin and the second fin, there is a problem in that large pressure loss occurs before the liquid coolant reaches between the multiple fin elements of the first fin and between the multiple fin elements of the second fin. To address this issue, it is conceivable to use a large pump to supply liquid refrigerant to the light source cooling section, but this would result in an increase in the size of the cooling device, which in turn would increase the size of the projector. For this reason, there has been a demand for a different configuration that can efficiently cool the object to be cooled. [Means for solving the problem]

[0006] A light source device according to a first aspect of the present disclosure includes a light source module having a plurality of bases on which light emitting elements are arranged, a plurality of heat receiving plates connected to the light source module, and a cooling plate connected to each of the plurality of heat receiving plates and through which a coolant flows, the cooling plate having an inlet portion provided at a portion in a first direction along an end portion and through which the coolant flows, an outlet portion provided at a portion in a direction opposite to the first direction with respect to the portion and through which the coolant flows out, an upstream circulation portion through which the coolant flowing in from the inlet portion flows in a second direction perpendicular to the first direction, and the coolant having flowed through the upstream circulation portion flows in the second direction. and a downstream circulation section in which the cooling liquid flows in the opposite direction to the upstream circulation section, and a plurality of heat transfer sections provided in at least one of the circulation sections of the upstream circulation section and the downstream circulation section and arranged side by side in the second direction, wherein the plurality of heat transfer sections extend along the second direction and have a plurality of fins arranged along the first direction and a plurality of flow paths provided between the plurality of fins and through which the cooling liquid can flow, and the plurality of heat receiving plates are arranged along the second direction according to the at least one circulation section, and each of the plurality of heat transfer sections is spaced apart from one another at positions corresponding to the spaces between the plurality of heat receiving plates in the second direction.

[0007] A light source device according to a second aspect of the present disclosure includes a light source module having a plurality of bases on which light emitting elements are arranged, one heat receiving plate connected to the light source module, and a cooling plate connected to the heat receiving plate and through which a coolant flows, the cooling plate having an inlet portion provided at a portion in a first direction along an end portion and through which the coolant flows, an outlet portion provided at a portion in a direction opposite to the first direction with respect to the portion and through which the coolant flows out, an upstream circulation portion through which the coolant that flows in from the inlet portion flows in a second direction perpendicular to the first direction, and an outlet portion through which the coolant that has flowed through the upstream circulation portion flows in the second direction. and a plurality of heat transfer parts provided in at least one of the upstream and downstream circulation parts and arranged side by side in the second direction, wherein the plurality of heat transfer parts extend along the second direction and have a plurality of fins arranged along the first direction, and a plurality of flow paths provided between the plurality of fins and through which the coolant can flow, the plurality of bases are arranged side by side in the second direction, and each of the plurality of heat transfer parts is spaced apart from one another at a position corresponding to between two of the plurality of light-emitting elements arranged side by side in the second direction.

[0008] A light source device according to a third aspect of the present disclosure includes a light source module having a plurality of bases on which light emitting elements are arranged, a plurality of heat receiving plates connected to the light source module, and a cooling plate connected to each of the plurality of heat receiving plates and through which a coolant flows, the cooling plate having an inlet portion provided in a portion in a first direction along an end portion and through which the coolant flows, an outlet portion provided in a portion in a direction opposite to the first direction with respect to the portion and through which the coolant flows out, an upstream circulation portion through which the coolant flowing in from the inlet portion flows in a second direction perpendicular to the first direction, a downstream circulation portion through which the coolant having flowed through the upstream circulation portion flows in a direction opposite to the second direction, and a plurality of cooling plates provided in at least one circulation portion of the upstream circulation portion and the downstream circulation portion and provided along the second direction. and a heat transfer section in which the plurality of heat transfer sections extend along the second direction and have a plurality of fins arranged along the first direction, and a plurality of flow paths provided between the plurality of fins and through which the coolant can flow, the plurality of bases are arranged in a line in the second direction, and the plurality of heat receiving plates include an upstream heat receiving plate provided in accordance with the upstream flow section and a downstream heat receiving plate provided in accordance with the downstream flow section, the plurality of bases include a plurality of upstream bases arranged in a line in the second direction and connected to the upstream heat receiving plate, and a plurality of downstream bases arranged in a line in the second direction and connected to the downstream heat receiving plate, and each of the plurality of heat transfer sections is spaced apart from each other at a position corresponding to between two of the plurality of light-emitting elements arranged in the second direction.

[0009] A projector according to a fourth aspect of the present disclosure includes a light source device according to any one of the first to third aspects, an image forming device that modulates light emitted from the light source device to form image light, and a projection optical device that projects the image light formed by the image forming device.

[0010] A cooling plate according to a fifth aspect of the present disclosure is a cooling plate through which a coolant can flow, and comprises: an inlet portion provided in a portion in a first direction along an edge portion and through which the coolant flows; an outlet portion provided in a portion opposite the first direction relative to the portion through which the coolant flows; an upstream circulation portion through which the coolant flowing in from the inlet portion flows in a second direction perpendicular to the first direction; a downstream circulation portion through which the coolant that has flowed through the upstream circulation portion flows in a direction opposite to the second direction; and a plurality of heat transfer portions provided in at least one of the upstream circulation portion and the downstream circulation portion and arranged side by side in the second direction, wherein the plurality of heat transfer portions extend along the second direction and have a plurality of fins arranged along the first direction and a plurality of flow paths provided between the plurality of fins through which the coolant can flow, and each of the plurality of heat transfer portions is spaced apart from each other in the second direction. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a projector according to a first embodiment. [Figure 2] FIG. 1 is a schematic diagram showing the configuration of a light source device according to a first embodiment. [Figure 3] FIG. 2 is a schematic diagram showing the configuration of a light source unit according to the first embodiment. [Figure 4] FIG. 2 is a plan view showing a first light source unit according to the first embodiment. [Figure 5] FIG. 2 is an exploded perspective view showing a first cooling plate according to the first embodiment. [Figure 6] FIG. 2 is an exploded perspective view showing a first cooling plate according to the first embodiment. [Figure 7] FIG. 2 is a cross-sectional view showing a first cooling plate according to the first embodiment. [Figure 8] FIG. 3 is a schematic view showing the positional relationship between a first heat receiving plate and a heat transfer portion according to the first embodiment. [Figure 9] FIG. 3 is a perspective view showing a connection state between a first cooling plate and a second cooling plate according to the first embodiment. [Figure 10] 5A and 5B are schematic views showing modifications of the first light source unit according to the first embodiment. [Figure 11] FIG. 10 is a schematic diagram showing a first light source section of a light source device provided in a projector according to a second embodiment. [Figure 12] 10A and 10B are schematic diagrams showing modifications of the first light source unit according to the second embodiment. [Figure 13] FIG. 11 is a schematic diagram showing a first light source section of a light source device included in a projector according to a third embodiment. [Figure 14] FIG. 10 is a schematic diagram showing a first light source section of a light source device included in a projector according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] [First embodiment] A first embodiment of the present disclosure will be described below with reference to the drawings. [Projector configuration] FIG. 1 is a schematic diagram showing the configuration of a projector 1 according to this embodiment. The projector 1 according to this embodiment modulates light emitted from a light source device 4 to form an image according to image information, and enlarges and projects the formed image onto a projection surface such as a screen. As shown in Fig. 1, the projector 1 includes an exterior housing 2 and an image projection device 3. In addition, although not shown, the projector 1 also includes a power supply device that supplies power to electronic components that make up the projector 1, a control device that controls the operation of the projector 1, and a cooling device that cools objects that make up the projector 1. The cooling device has a circulation flow path through which the coolant circulates to first cooling plate 615 and second cooling plate 625 (see FIG. 3), which will be described later. Specifically, the cooling device includes a tank that stores the coolant, a radiator that cools the coolant, a pump that pressure-feeds the coolant, and multiple pipes. The multiple pipes connect the tank, radiator, pump, first cooling plate 615, and second cooling plate 625 so that the coolant can circulate.

[0013] [Exterior casing configuration] The exterior housing 2 constitutes the exterior of the projector 1, and houses the image projection device 3, a power supply device, a control device, and a cooling device inside. The exterior housing 2 has a front surface 21, a rear surface 22, a left side surface 23, and a right side surface 24. Although not shown, the exterior housing 2 has a top surface connecting one end of each of the surface portions 21 to 24, and a bottom surface connecting the other end of each of the surface portions 21 to 24. The exterior housing 2 is formed, for example, in a substantially rectangular parallelepiped shape.

[0014] The right side surface portion 24 has an inlet 241. The inlet 241 introduces air from outside the exterior housing 2 into the interior of the exterior housing 2. The inlet 241 may be provided with a filter that collects dust contained in the air passing through the inlet 241. The front surface 21 has a passage opening 211 located approximately in the center of the front surface 21. Light projected from a projection optical device 36, which will be described later, passes through the passage opening 211. The front surface portion 21 has an exhaust port 212 located on the left side surface portion 23 side of the front surface portion 21. The exhaust port 212 discharges air that has cooled an object to be cooled provided inside the exterior housing 2 to the outside of the exterior housing 2.

[0015] In the following description, three mutually orthogonal directions are referred to as the +X direction, the +Y direction, and the +Z direction. The +X direction is the direction from the left side surface portion 23 to the right side surface portion 24. The +X direction is along the direction in which the light source device 4, described later, emits illumination light to the homogenizer 31. The +Y direction is the direction from the bottom surface portion to the top surface portion. The +Z direction is the direction from the back surface portion 22 to the front surface portion 21. The +Z direction, when viewed from the +Y direction, is along the direction in which the projection optical device 36, described later, projects image light. Although not shown in the drawings, the direction opposite to the +X direction is referred to as the -X direction, the direction opposite to the +Y direction is referred to as the -Y direction, and the direction opposite to the +Z direction is referred to as the -Z direction.

[0016] [Configuration of image projection device] The image projection device 3 forms an image according to image information input from the control device and projects the formed image. The image projection device 3 includes a light source device 4, a uniformization device 31, a color separation device 32, a relay device 33, an image formation device 34, an optical component housing 35, and a projection optical device 36. The configuration of the light source device 4 will be described in detail later.

[0017] The homogenizer 31 homogenizes the light emitted from the light source device 4. The homogenized light passes through a color separator 32 and a relay device 33, and illuminates a modulation area of ​​a light modulator 343 (described later). The homogenizer 31 includes two lens arrays 311 and 312, a polarization conversion element 313, and a superimposing lens 314. The color separator 32 separates the light incident from the uniformizer 31 into red, green, and blue light. The color separator 32 includes two dichroic mirrors 321 and 322, and a reflecting mirror 323 that reflects the blue light separated by the dichroic mirror 321.

[0018] Relay device 33 is provided on the optical path of red light, which is longer than the optical paths of the other colored lights, to suppress loss of the red light. Relay device 33 includes an incident-side lens 331, a relay lens 333, and reflecting mirrors 332 and 334. In this embodiment, relay device 33 is provided on the optical path of red light. However, this is not limiting, and for example, a configuration may be adopted in which blue light is the colored light whose optical path is longer than the other colored lights, and relay device 33 is provided on the optical path of the blue light.

[0019] The image forming device 34 modulates the incident red, green, and blue colored light and combines the modulated colored light to form image light. That is, the image forming device 34 modulates the light emitted from the light source device 4 to form image light. The image forming device 34 includes three field lenses 341, three incident-side polarizing plates 342, three light modulation devices 343, three viewing angle compensating plates 344, and three exit-side polarizing plates 345, which are provided according to the incident colored light, and one color combining unit 346.

[0020] The light modulation devices 343 modulate the light emitted from the light source device 4 in accordance with image information. The three light modulation devices 343 include a light modulation device 343R that modulates red light, a light modulation device 343G that modulates green light, and a light modulation device 343B that modulates blue light. The light modulation devices 343 are configured with transmissive liquid crystal panels, and the incident-side polarizing plate 342, the light modulation devices 343, and the exit-side polarizing plate 345 configure a liquid crystal light valve. The color combining unit 346 combines the three color lights modulated by the light modulation devices 343B, 343G, and 343R to form image light, and emits the formed image light to the projection optical device 36. In this embodiment, the color combining unit 346 is configured by a cross dichroic prism, but is not limited to this, and can also be configured by, for example, a plurality of dichroic mirrors.

[0021] The optical component housing 35 accommodates the above-mentioned devices 31 to 34 inside. The image projection device 3 has an illumination optical axis Ax, which is a design optical axis, set therein, and the optical component housing 35 holds the devices 31 to 34 at predetermined positions on the illumination optical axis Ax. The light source device 4 and the projection optical device 36 are disposed at predetermined positions on the illumination optical axis Ax.

[0022] The projection optical device 36 is a projection lens that enlarges and projects the image light incident from the image forming device 34 onto a projection surface. In other words, the projection optical device 36 projects the image light formed by the image forming device 34. An example of the projection optical device 36 is a lens assembly that has a plurality of lenses and a cylindrical lens barrel that houses the plurality of lenses inside.

[0023] [Light source configuration] FIG. 2 is a schematic diagram showing the light source device 4. As shown in FIG. The light source device 4 emits illumination light that illuminates the image forming device 34 to the homogenizing device 31. As shown in FIG. 2 , the light source device 4 includes a light source housing CA, an afocal optical element 41, a first phase difference element 42, a diffuse transmission element 43, a light separation / combination element 44, a second phase difference element 45, a first light-collecting element 46, a diffusion optical element 47, a second light-collecting element 48, a wavelength conversion element 49, a third phase difference element 50, and a light source unit 6.

[0024] The light source device 4 is set with an illumination optical axis Ax1 that extends linearly along the −Z direction and an illumination optical axis Ax2 that is perpendicular to the illumination optical axis Ax1 and extends linearly along the +X direction. The light source unit 6, the afocal optical element 41, the first phase difference element 42, the diffuse transmission element 43, the light separation / combination element 44, the second phase difference element 45, the first focusing element 46, and the diffusion optical element 47 are arranged on the illumination optical axis Ax1. The wavelength conversion element 49, the second light-collecting element 48, the light separating / combining element 44, and the third phase difference element 50 are arranged on the illumination optical axis Ax2.

[0025] [Configuration of the light source housing] The light source housing CA houses an afocal optical element 41, a first phase difference element 42, a diffuse transmission element 43, a light separation / combination element 44, a second phase difference element 45, a first light-collecting element 46, a diffuse optical element 47, a second light-collecting element 48, a wavelength conversion element 49, a third phase difference element 50, and a light source unit 6, and is an airtight housing that makes it difficult for dust and other particles to enter the interior.

[0026] [Light source configuration] Fig. 3 is a schematic diagram showing the configuration of the light source section 6. Specifically, Fig. 3 is a schematic diagram showing a cross section of the light source section 6 as viewed from the -X direction. The light source unit 6 emits light incident on a diffusion optical element 47 and a wavelength conversion element 49 (described later) in the −Z direction. As shown in FIG. 3, the light source unit 6 includes a first light source unit 61, a second light source unit 62, and a light combining member 63. The first light source unit 61 is arranged in the +Z direction in the light source unit 6. The first light source unit 61 includes a first light source module 611, a first heat receiving plate 614, and a first cooling plate 615, and emits blue light source light in the -Z direction. The first cooling plate 615 cools the first light source module 611 by transferring heat transferred from the first light source module 611 via the first heat receiving plate 614 to a coolant flowing inside.

[0027] The second light source unit 62 is disposed in the -Y direction in the light source unit 6. The second light source unit 62 includes a second light source module 621, a second heat receiving plate 624, and a second cooling plate 625, and emits blue light source light in the +Y direction. The second cooling plate 625 cools the second light source module 621 by transferring heat transferred from the second light source module 621 via the second heat receiving plate 624 to a coolant flowing inside. The detailed configurations of the first light source unit 61 and the second light source unit 62 will be described later.

[0028] The light combining member 63 is provided at a position where the optical path of the light source light emitted from the first light source unit 61 intersects with the optical path of the light source light emitted from the second light source unit 62. The light combining member 63 combines the light source light emitted in the -Z direction from the first light source unit 61 and the light source light emitted in the +Y direction from the second light source unit 62, and emits the combined light in the -Z direction. An example of the light combining member 63 is a stripe mirror. The light source light emitted by such a light source unit 6 is, for example, laser light with a peak wavelength of 440 nm. More specifically, the light source light emitted by the light source unit 6 is s-polarized blue light BLs directed to the light separating / combining element 44. The light source unit 6 may alternatively emit p-polarized blue light BLp directed to the light separating / combining element 44, or may emit blue light that is a mixture of s-polarized and p-polarized light. In the latter case, the first phase difference element 42 can be omitted.

[0029] [Configuration of afocal optical elements] The afocal optical element 41 adjusts the beam diameter of the blue light BLs incident in the −Z direction from the light source unit 6. The afocal optical element 41 is composed of a lens 411 that condenses the incident light and a lens 412 that collimates the beam condensed by the lens 411. Note that the afocal optical element 41 may be omitted.

[0030] [Configuration of the first phase difference element] The first phase difference element 42 is provided between the lens 411 and the lens 412. The first phase difference element 42 converts a portion of the incident blue light BLs and emits light containing s-polarized blue light BLs and p-polarized blue light BLp. The first phase difference element 42 may be rotated by a rotating device about a rotation axis along the illumination optical axis Ax1. In this case, the ratio of s-polarized components to p-polarized components in the blue light emitted from the first phase difference element 42 can be adjusted according to the rotation angle of the first phase difference element 42.

[0031] [Configuration of diffuse transmission element] The diffuse transmission element 43 homogenizes the illuminance distribution of the blue light BLp, BLs incident in the −Z direction from the lens 412. Examples of the diffuse transmission element 43 include a configuration having a hologram, a configuration in which a plurality of small lenses are arranged in a plane perpendicular to the optical axis, and a configuration in which the surface through which light passes is rough. Instead of the diffuse transmission element 43, a homogenizer optical element having a pair of multi-lenses may be used.

[0032] [Configuration of the light splitting / combining element] The blue light BLs and BLp that have passed through the diffuse transmission element 43 are incident on the light separation / combination element 44 . The light separating / combining element 44 has a function as a light separating element that separates incident light and a function as a light combining element that combines light incident from two directions. In other words, the light separating / combining element 44 functions as a light separating element as well as a light combining element. The light separating / combining element 44 is a polarizing beam splitter that separates the incident light into s-polarized and p-polarized components. Specifically, the light separating / combining element 44 reflects the s-polarized component and transmits the p-polarized component. The light separating / combining element 44 also has color separation characteristics that allow it to transmit light of a predetermined wavelength or longer, regardless of whether it is an s-polarized component or a p-polarized component. Therefore, of the blue light BLp and BLs incident on the light separating / combining element 44 from the diffuse transmission element 43, the p-polarized blue light BLp transmits through the light separating / combining element 44 in the −Z direction and enters the second phase difference element 45. Meanwhile, the s-polarized blue light BLs is reflected by the light separating / combining element 44 in the −X direction and enters the second focusing element 48. The light separating / combining element 44 may have both a function as a half mirror that transmits a portion of the light incident from the light source unit 6 via the diffuse transmission element 43 and reflects the remaining light, and a function as a dichroic mirror that reflects the blue light incident from the diffusion optical element 47 and transmits the fluorescence that is incident from the wavelength conversion element 49 and has a wavelength longer than that of the blue light. In this case, the first phase difference element 42 can be omitted.

[0033] [Configuration of the second phase difference element] The second phase difference element 45 is disposed in the −Z direction with respect to the light separation / combining element 44. That is, the second phase difference element 45 is disposed between the light separation / combining element 44 and the first light collecting element 46. The second phase difference element 45 converts the blue light BLp that has passed through the light separation / combining element 44 into circularly polarized blue light BLc. The blue light BLc that has passed through the second phase difference element 45 in the −Z direction is incident on the first light collecting element 46.

[0034] [Configuration of the first light-collecting element] The first light-collecting element 46 collects the blue light BLc that has passed through the light separation / combination element 44 in the -Z direction and is incident from the second phase difference element 45 onto the diffusing optical element 47. The first light-collecting element 46 also collimates the light that is incident from the diffusing optical element 47 in the +Z direction and outputs the collimated light to the second phase difference element 45. In this embodiment, the first light-collecting element 46 is composed of three lenses 461, 462, and 463, but the number of lenses that constitute the first light-collecting element 46 is not limited.

[0035] [Configuration of diffusive optical element] The diffusing optical element 47 diffuses the incident blue light BLc at the same diffusion angle as the fluorescence YL emitted from the wavelength conversion element 49. Specifically, the diffusing optical element 47 reflects the blue light BLc incident in the -Z direction from the first light collecting element 46 in the +Z direction to diffuse it. The diffusing optical element 47 is a reflecting element that performs Lambertian reflection on the incident blue light BLc. Note that the diffusing optical element 47 may be rotated around a rotation axis parallel to the illumination optical axis Ax1 by a rotating device. The blue light BLc diffused by the diffusing optical element 47 passes through the first light-collecting element 46 and then enters the second phase difference element 45. When the blue light BLc incident on the diffusing optical element 47 is reflected by the diffusing optical element 47, it is converted into circularly polarized light with the opposite rotation direction. Therefore, the blue light BLc incident on the second phase difference element 45 via the first light-collecting element 46 is converted into s-polarized blue light BLs by the second phase difference element 45. The blue light BLs is then reflected in the +X direction by the light separating / combining element 44 and enters the third phase difference element 50.

[0036] [Configuration of the second focusing element] The second light collecting element 48 collects the blue light BLs reflected in the -X direction by the light separating / combining element 44 onto the wavelength converting element 49. The second light collecting element 48 also collimates the fluorescence YL incident in the +X direction from the wavelength converting element 49, and emits the collimated fluorescence YL to the light separating / combining element 44. In this embodiment, the second light collecting element 48 is composed of three lenses 481, 482, and 483, but the number of lenses that constitute the second light collecting element 48 is not limited.

[0037] [Schematic configuration of wavelength conversion element] The wavelength conversion element 49 converts the wavelength of the blue light BLs incident from the second light collecting element 48. That is, the wavelength conversion element 49 converts the blue light BLs incident from the second light collecting element 48 into fluorescence YL having a wavelength longer than that of the blue light BLs and emits the fluorescence YL. The wavelength conversion element 49 is a reflective wavelength conversion element that emits the fluorescence YL to the incident side of the blue light BLs. The blue light BLs incident on the wavelength conversion element 49 corresponds to excitation light or light of the first wavelength band, and the fluorescence YL corresponds to converted light or light of the second wavelength band. The wavelength conversion element 49 includes a phosphor wheel 491 and a rotation device 495 that rotates the phosphor wheel 491. The phosphor wheel 491 includes a wavelength conversion layer 492, a reflective layer 493, and a support substrate 494. The wavelength conversion layer 492 contains a phosphor and is provided in a ring shape centered on the rotation axis of the phosphor wheel 491. The reflective layer 493 is provided on the opposite side of the wavelength conversion layer 492 from the incident side of the excitation light, and reflects light incident from the wavelength conversion layer 492. The support substrate 494 supports the wavelength conversion layer 492 and the reflective layer 493. The wavelength conversion element 49 may be configured not to be rotated by a rotation device.

[0038] The fluorescence YL emitted in the +X direction from the wavelength conversion element 49 is collimated by the second light collecting element 48 and then enters the light separation / combining element 44. As described above, the light separation / combining element 44 has the property of transmitting the fluorescence YL, and therefore the fluorescence YL that enters the light separation / combining element 44 along the +X direction passes through the light separation / combining element 44 and enters the third phase difference element 50. In other words, the light that enters the third phase difference element 50 from the light separation / combining element 44 is white light that is a mixture of blue light BLs and fluorescence YL.

[0039] [Configuration of the third phase difference element] The third phase difference element 50 converts the white light containing the blue light BLs and the fluorescence YL incident from the light separating / combining element 44 into white light containing a mixture of s-polarized light and p-polarized light. The white light converted in this manner is emitted in the +X direction as illumination light LT and enters the homogenizing device 31 described above.

[0040] [Configuration of the first light source unit] Fig. 4 is a plan view schematically showing the first light source unit 61 as viewed from the -Z direction. That is, Fig. 4 is a schematic diagram showing the first light source unit 61 as viewed from the light source light emission side. As shown in FIG. 4, the first light source unit 61 includes a first light source module 611, a first heat receiving plate 614, and a first cooling plate 615.

[0041] [Configuration of the first light source module] The first light source module 611 emits blue light. The first light source module 611 includes a plurality of bases 612 arranged on a plane perpendicular to the optical axis of the emitted blue light. The first light source module 611 includes a plurality of bases 612 aligned in the +X direction and the +Y direction. Each of the plurality of bases 612 is formed in a rectangular parallelepiped shape that is long in the +Y direction. Each of the plurality of bases 612 holds at least one light emitting element 613. In other words, the bases 612 are support members that support the light emitting elements 613. The bases 612 are made of a metal with high thermal conductivity, and transfer heat generated by the light emitting elements 613 to the first heat receiving plate 614. In this embodiment, each of the multiple bases 612 has two light-emitting elements 613 aligned in the +Y direction. The +Y direction corresponds to the first direction. However, the number of light-emitting elements 613 included in the base 612 can be changed as appropriate. Specifically, the number of light-emitting elements 613 included in the base 612 may be one, or may be three or more.

[0042] The light-emitting element 613 is a semiconductor laser that emits blue light BLs. However, the light-emitting element 613 may be configured to emit p-polarized blue light BLp to the light separating / combining element 44. As described above, the blue light emitted by the light-emitting element 613 is laser light with a peak wavelength of 440 nm, for example. The blue light emitted from the multiple light-emitting elements 613 is collimated by a collimator lens (not shown) and then emitted.

[0043] Here, the multiple bases 612 include six upstream bases 612A arranged in the +Y direction and aligned in the +X direction, and six downstream bases 612B arranged in the -Y direction and aligned in the +X direction. That is, the first light source module 611 has 12 bases 612. The six upstream bases 612A are bases 612 arranged corresponding to the upstream flow section 6185 provided in the first cooling plate 615, which will be described later. The upstream bases 612A are attached to an upstream heat receiving plate 614A, which will be described later, out of the multiple first heat receiving plates 614. The six downstream bases 612B are bases 612 arranged corresponding to the downstream flow sections 6186 provided in the first cooling plate 615. The downstream bases 612B are attached to downstream heat receiving plates 614B, which will be described later, among the multiple first heat receiving plates 614.

[0044] [Configuration of the first heat receiving plate] The multiple first heat receiving plates 614 are provided between the first light source module 611 and the first cooling plate 615. The multiple first heat receiving plates 614 support the multiple bases 612, and receive heat from the light emitting elements 613 transferred from the bases 612, and transfer the heat to the first cooling plate 615. Each of the multiple first heat receiving plates 614 is formed in a substantially rectangular shape that is larger than the base 612 when viewed from the −X direction, which is the emission side of the light source light from the first light source module 611.

[0045] In this embodiment, the multiple first heat receiving plates 614 include three upstream heat receiving plates 614A arranged in the +Y direction and lined up in the +X direction, and three downstream heat receiving plates 614B arranged in the -Y direction and lined up in the +X direction. The three upstream heat receiving plates 614A are first heat receiving plates 614 arranged corresponding to the upstream flow section 6185 in the first cooling plate 615. Each of the three upstream heat receiving plates 614A supports two of the six upstream bases 612A. That is, each of the three upstream heat receiving plates 614A is arranged side by side in the +X direction while supporting two upstream bases 612A. The three downstream heat receiving plates 614B are first heat receiving plates 614 arranged corresponding to the downstream flow section 6186 in the first cooling plate 615. Each of the three downstream heat receiving plates 614B also supports two of the six downstream bases 612B. That is, each of the three downstream heat receiving plates 614B is arranged side by side in the +X direction while supporting two downstream bases 612B.

[0046] [Configuration of the first cooling plate] FIG. 5 is an exploded perspective view of the first cooling plate 615 as seen from the light source light emission side, and FIG. 6 is an exploded perspective view of the first cooling plate 615 as seen from the opposite side to the light source light emission side. The first cooling plate 615 is a heat exchanger that has a cooling flow path therein through which a coolant can flow and transfers transferred heat to the coolant. As shown in Figures 5 and 6, the first cooling plate 615 includes a first plate element 616 and a second plate element 618, and is configured by fixing the second plate element 618 to the first plate element 616 with a plurality of screws SC.

[0047] [Configuration of the first plate element] 5, the first plate element 616 has a first surface 616A on which a plurality of first heat receiving plates 614 are arranged. Three upstream heat receiving plates 614A are arranged in a heat-transferable manner on a portion of the first surface 616A in the +Y direction, and three downstream heat receiving plates 614B are arranged in a heat-transferable manner on a portion of the first surface 616A in the -Y direction. In other words, the first surface 616A is a heat receiving surface that receives heat from the plurality of first heat receiving plates 614.

[0048] As shown in FIG. 6, the first plate element 616 has a plurality of heat transfer portions 617, grooves 6161, and a sealing member 6162 on a second surface 616B opposite to the first surface 616A. The multiple heat transfer sections 617 are arranged in recesses 6183 of a second plate element 618, which will be described later. The multiple heat transfer sections 617 include three upstream heat transfer sections 617A arranged in the +Y direction and aligned in the +X direction on the second surface 616B, and three downstream heat transfer sections 617B arranged in the -Y direction and aligned in the +X direction.

[0049] The three upstream heat transfer portions 617A are arranged in the upstream flow portion 6185 (see FIGS. 6 and 7) in the recess 6183 when the first plate element 616 and the second plate element 618 are combined. The three upstream heat transfer portions 617A are spaced apart from one another in the +X direction. In other words, the first cooling plate 615 has gaps GP1 between the three upstream heat transfer portions 617A in the +X direction. The three downstream heat transfer portions 617B are arranged in the downstream flow portion 6186 (see FIGS. 6 and 7) in the recess 6183 when the first plate element 616 and the second plate element 618 are combined. The three downstream heat transfer portions 617B are spaced apart from one another in the +X direction. In other words, the first cooling plate 615 has gaps GP2 between the three downstream heat transfer portions 617B in the +X direction.

[0050] Each of the plurality of heat transfer portions 617 has a plurality of fins 6171 and a plurality of flow paths 6172 . The fins 6171 extend along the +X direction (second direction) and are arranged along the +Y direction (first direction). The fins are made of a metal with high thermal conductivity. The plurality of flow paths 6172 are provided between the plurality of fins 6171 and are flow paths through which the coolant can flow. When the plurality of heat transfer units 617 are arranged in the recess 6183, the coolant in the recess 6183 flows along the plurality of flow paths 6172. At this time, heat is transferred from the plurality of fins 6171 to the coolant.

[0051] The grooves 6161 are provided in the second surface 616B and surround the heat transfer portions 617 when viewed from the +Z direction on the side of the second plate element 618. The grooves 6161 are recessed in the -Z direction from the second surface 616B. The sealing member 6162 is disposed in the groove 6161. More specifically, the sealing member 6162 is a packing that fits into the groove 6161. The sealing member 6162 seals the gap between the first plate element 616 and the second plate element 618, thereby preventing the coolant from leaking out of the first cooling plate 615.

[0052] [Configuration of the second plate element] As shown in Figures 5 and 6, the second plate element 618 is positioned on the opposite side of the first plate element 616 from the first light source module 611 and the multiple first heat receiving plates 614, and is attached to the second surface 616B by multiple screws SC. The second plate element 618 has an opposing surface 618A opposing the first plate element 616, an inlet portion 6181, an outlet portion 6182, a recess 6183, a partition wall 6184, an upstream flow portion 6185, a downstream flow portion 6186, and a connection portion 6187.

[0053] The inlet portion 6181 is provided at an end portion 618B of the second plate element 618 in the -X direction, at a position in the +Y direction (first direction) along the end portion 618B. Coolant flows into the inlet portion 6181 from the outside. The inlet portion 6181 communicates with the space inside the recessed portion 6183, and the coolant that flows into the inlet portion 6181 flows into the space inside the recessed portion 6183. The end portion 618B constitutes the end portion 615A of the first cooling plate 615 in the -X direction. The outlet portion 6182 is provided at an end portion 618B of the second plate element 618 in the -X direction, in a portion in the -Y direction (opposite to the first direction) relative to the portion in the +Y direction where the inlet portion 6181 is provided. The outlet portion 6182 communicates with the space within the recessed portion 6183, and allows the coolant that has circulated within the recessed portion 6183 to flow out to the outside.

[0054] The recess 6183 is provided approximately in the center of the opposing surface 618A, is recessed on the opposite side to the first plate element 616, and is formed in a substantially rectangular shape when viewed from the side of the first plate element 616. Of the outer edges of the recess 6183, two sides extend along the +X direction, and the other two sides extend along the +Y direction. The partition wall 6184 divides the space inside the recess 6183. Specifically, the partition wall 6184 extends in the +X direction on the inner wall of the recess 6183 in the -X direction from the center in the +Y direction to a position not reaching the inner edge of the recess 6183 in the +X direction.

[0055] The upstream circulation section 6185 and the downstream circulation section 6186 are spaces within the recess 6183 that are separated by the partition wall 6184. The upstream circulation section 6185 is the space in the +Y direction with respect to the partition wall 6184 within the space within the recess 6183 that is separated by the partition wall 6184. The downstream circulation section 6186 is the space in the -Y direction with respect to the partition wall 6184 within the space within the recess 6183 that is separated by the partition wall 6184. When the first plate element 616 and the second plate element 618 are combined, three upstream heat transfer sections 617A are arranged in the upstream flow section 6185. Similarly, three downstream heat transfer sections 617B are arranged in the downstream flow section 6186.

[0056] The connection portion 6187 is provided in the recess 6183 on the opposite side to the inlet portion 6181 and the outlet portion 6182, and connects the upstream circulation portion 6185 and the downstream circulation portion 6186. The connection portion 6187 is formed when the partition wall 6184 does not reach the inner wall of the recess 6183 in the +X direction.

[0057] [Cooling channel in the first cooling plate] Fig. 7 is a diagram showing a cross section along the XY plane of the first cooling plate 615. In other words, Fig. 7 is a diagram showing the flow path of the coolant in the first cooling plate 615. Note that the bold arrows AR in Fig. 7 indicate the flow direction of the coolant. As shown in FIG. 7, the coolant that flows into the first cooling plate 615 from the inlet portion 6181 flows in the +X direction through an upstream flow portion 6185 that is partitioned by a partition wall 6184. At this time, the coolant flows through the multiple flow paths 6172 (see FIG. 6) of the upstream heat transfer portion 617A that is located most upstream of the three upstream heat transfer portions 617A, and then reaches the gap GP1 in the -X direction. After this, the coolant flows through the multiple flow paths 6172 of the upstream heat transfer portion 617A that is located at the center in the +X direction, and then reaches the gap GP1 in the +X direction. Then, the coolant flows through the multiple flow paths 6172 of the upstream heat transfer portion 617A that is located most downstream, and then reaches the connection portion 6187. In this way, while the coolant flows through the upstream flow section 6185, heat is transferred to the coolant from the plurality of fins 6171 that each of the three upstream heat transfer sections 617A has.

[0058] The coolant that has reached the connecting portion 6187 flows through the connecting portion 6187 in the -Y direction, and then flows in the -X direction through the downstream circulation portion 6186 partitioned by the partition wall 6184. At this time, the coolant flows sequentially through the multiple flow paths 6172 of the +X direction downstream heat transfer portion 617B, the +X direction gap GP2, the multiple flow paths 6172 of the central downstream heat transfer portion 617B, the -X direction gap GP2, and the multiple flow paths 6172 of the -X direction downstream heat transfer portion 617B. As the coolant flows through the downstream circulation portion 6186 in this manner, heat is transferred to the coolant from the multiple fins 6171 of each of the three downstream heat transfer portions 617B. The cooling liquid that has flowed through the downstream flow portion 6186 is discharged to the outside of the first cooling plate 615 through the outflow portion 6182.

[0059] [Spaced placement of heat transfer parts] As described above, the three upstream heat transfer sections 617A are spaced apart from one another in the +X direction in which the coolant flows. In other words, a gap GP1 is provided between the three upstream heat transfer sections 617A, separating adjacent upstream heat transfer sections 617A. This configuration reduces the pressure loss of the coolant flowing through the upstream flow section 6185 compared to a configuration in which a single heat transfer section having dimensions equal to the sum of the three upstream heat transfer sections 617A and the two gaps GP1 in the +X direction is provided instead of the three upstream heat transfer sections 617A. This configuration facilitates the flow of the coolant through the three upstream heat transfer sections 617A without employing a large pump in the cooling device. This configuration improves the cooling efficiency of the first cooling plate 615 for the multiple upstream bases 612A, i.e., the cooling efficiency of the light-emitting elements 613 arranged on the multiple upstream bases 612A, and also prevents the projector 1 from becoming too large.

[0060] The three downstream heat transfer sections 617B are also spaced apart from one another in the +X direction in which the coolant flows by providing the gaps GP2. This reduces the pressure loss of the coolant flowing through the downstream heat transfer sections 617B compared to when a single heat transfer section having a dimension equal to the sum of the three downstream heat transfer sections 617B and the two gaps GP2 in the +X direction is provided instead of the three downstream heat transfer sections 617B. This makes it possible to facilitate the flow of the coolant through the downstream flow section 6186 without employing a large pump in the cooling device. This increases the cooling efficiency of the first cooling plate 615 for the multiple downstream bases 612B, i.e., the cooling efficiency of the light-emitting elements 613 arranged on the multiple downstream bases 612B, and also prevents the projector 1 from becoming larger.

[0061] [Position of gap separating heat transfer parts] Fig. 8 is a schematic diagram showing the positional relationship between the first heat receiving plate 614 and the heat transfer portion 617. In other words, Fig. 8 is a schematic diagram showing the positions where the multiple heat transfer portions 617 are spaced apart, that is, the positions of the gaps GP1 and GP2. The positions where the plurality of heat transfer portions 617 are spaced apart from one another, that is, the positions of the gaps GP1 and GP2 provided between the plurality of heat transfer portions 617, will be described below. 8, the heat transfer portions 617 are provided corresponding to the first heat receiving plates 614. Specifically, the three upstream heat transfer portions 617A are provided corresponding to the three upstream heat receiving plates 614A, respectively. As described above, the pressure loss of the coolant can be reduced by providing the gap GP1 between two adjacent upstream heat transfer portions 617A. The gaps GP1 provided between the three upstream heat transfer portions 617A correspond to the gaps between the three upstream heat receiving plates 614A.

[0062] Since the gap GP1 does not have the upstream heat transfer portion 617A, heat is not easily transferred to the coolant through the gap GP1. However, since the upstream heat transfer portion 617A is provided corresponding to the upstream heat receiving plate 614A, heat from the upstream base 612A can be efficiently transferred to the upstream heat transfer portion 617A via the upstream heat receiving plate 614A. This allows heat from the light emitting element 613 to be efficiently transferred from the upstream heat transfer portion 617A to the coolant.

[0063] Similarly, the three downstream heat transfer portions 617B are provided corresponding to the three downstream heat reception plates 614B, respectively. Therefore, the gaps GP2 provided between the three downstream heat transfer portions 617B are provided corresponding to the gaps between the three downstream heat reception plates 614B, respectively. As described above, by providing the gaps GP2 between two adjacent downstream heat transfer portions 617B, the pressure loss of the coolant can be reduced. Since the downstream heat transfer portion 617B is not present in the gap GP2, heat is not transferred to the coolant through the gap GP2. However, since the downstream heat transfer portion 617B is provided corresponding to the downstream heat receiving plate 614B, heat from the downstream base 612B can be efficiently transferred to the downstream heat transfer portion 617B via the downstream heat receiving plate 614B. This allows heat from the light emitting element 613 to be efficiently transferred from the downstream heat transfer portion 617B to the coolant.

[0064] [Configuration of the second light source] The second light source unit 62 has the same configuration as the first light source unit 61. That is, the second light source unit 62 includes a second light source module 621, a plurality of second heat receiving plates 624, and a second cooling plate 625, as shown in FIG. The second light source module 621 has a configuration similar to that of the first light source module 611. Specifically, the second light source module 621 has a plurality of bases 612 each having at least one light emitting element 613, and the plurality of bases 612 include three upstream bases 612A aligned in the +X direction and three downstream bases 612B aligned in the +X direction. The multiple second heat receiving plates 624 have the same configuration as the multiple first heat receiving plates 614. Specifically, the multiple second heat receiving plates 624 include three upstream heat receiving plates 614A aligned in the +X direction and three downstream heat receiving plates 614B aligned in the +X direction. The second cooling plate 625 has the same configuration as the first cooling plate 615. For example, the second cooling plate 625 has an inlet portion 6181 and an outlet portion 6182.

[0065] Fig. 9 is a perspective view showing a connection state between the first cooling plate 615 and the second cooling plate 625. In other words, Fig. 9 is a perspective view showing the light source casing CA to which the first light source unit 61 and the second light source unit 62 are attached. The outlet 6182 of the first cooling plate 615 is connected to the inlet 6181 of the second cooling plate 625 via a pipe CM. Therefore, as shown in Figures 3 and 9, the coolant that has flowed out from the outlet 6182 of the first cooling plate 615 flows into the inlet 6181 of the second cooling plate 625. Then, as shown by the dashed-dotted arrow in Figure 9, the coolant that has flowed into the second cooling plate 625 flows sequentially through the upstream circulation section 6185, the connection section 6187, and the downstream circulation section 6186 (see Figures 5 and 7) of the second cooling plate 625, and is discharged from the outlet 6182 of the second cooling plate 625.

[0066] Here, a coolant with a relatively low temperature flows into the inlet portion 6181 of the first cooling plate 615, and the coolant to which heat has been transferred by the first cooling plate 615 flows into the inlet portion 6181 of the second cooling plate 625. For this reason, the temperature of the coolant increases in the order of the upstream flow portion 6185 of the first cooling plate 615, the downstream flow portion 6186 of the first cooling plate 615, the upstream flow portion 6185 of the second cooling plate 625, and the downstream flow portion 6186 of the second cooling plate 625. On the other hand, generally, the lower the temperature of the light emitting element 613 within the effective temperature range, the greater the amount of light emitted by the light emitting element 613, and the higher the temperature of the light emitting element 613, the lower the amount of light emitted by the light emitting element 613.

[0067] For this reason, the first light source unit 61 and the second light source unit 62 are arranged so that the light emitted from the portion of the first light source unit 61 with a large amount of emitted light and the light emitted from the portion of the second light source unit 62 with a small amount of emitted light are combined by the light combining member 63, and so that the light emitted from the portion of the first light source unit 61 with a small amount of emitted light and the light emitted from the portion of the second light source unit 62 with a large amount of emitted light are combined. 3, the first light source unit 61 and the second light source unit 62 are arranged so that light emitted from the upstream base 612A of the first light source unit 61 and light emitted from the downstream base 612B of the second light source unit 62 are combined, and so that light emitted from the downstream base 612B of the first light source unit 61 and light emitted from the upstream base 612A of the second light source unit 62 are combined. This makes it possible to make the illuminance of the light emitted from the light source units 61 and 62 approximately uniform. In this embodiment, the upstream heat transfer sections 617A are spaced apart from one another in the +X direction, and the flow rate of the coolant is increased by spaced apart from one another in the +X direction. This also makes it easier to transfer heat from the light emitting elements 613 to the coolant, thereby preventing uneven brightness in the light emitted from the light source unit 6.

[0068] [Effects of the first embodiment] The projector 1 according to the present embodiment described above has the following advantages. The projector 1 includes a light source device 4, an image forming device 34 that modulates the light emitted from the light source device 4 to form image light, and a projection optical device 36 that projects the image light formed by the image forming device 34. The light source device 4 includes a light source section 6, which includes a first light source section 61 and a second light source section 62. The first light source section 61 includes a first light source module 611, a plurality of first heat receiving plates 614, and a first cooling plate 615. The first light source module 611 corresponds to the light source module, the plurality of first heat receiving plates 614 correspond to the plurality of heat receiving plates, and the first cooling plate 615 corresponds to the cooling plate. The first light source module 611 has a plurality of bases 612 on which light emitting elements 613 are arranged. The plurality of first heat receiving plates 614 are connected to the first light source module 611.

[0069] The first cooling plate 615 is connected to each of the multiple first heat receiving plates 614, and a coolant flows through the inside of the first cooling plate 615. The first cooling plate 615 includes an inlet portion 6181, an outlet portion 6182, an upstream side circulation portion 6185, a downstream side circulation portion 6186, and multiple heat transfer portions 617. The inlet portion 6181 is provided in a portion in the +Y direction (first direction) along the end portion 615A in the -X direction of the first cooling plate 615, and the coolant flows into the inlet portion 6181. The outlet portion 6182 is provided in a portion in the -Y direction relative to the +Y direction portion where the inlet portion 6181 is provided on the end portion 615A, and the coolant flows out of the outlet portion 6182. The coolant that flows in from the inlet portion 6181 flows in the +X direction (second direction) through the upstream circulation portion 6185. The coolant that has flowed through the upstream circulation portion 6185 flows in the -X direction through the downstream circulation portion 6186. A plurality of heat transfer portions 617 are provided in each of the upstream circulation portion 6185 and the downstream circulation portion 6186, and are arranged side by side in the +X direction.

[0070] The multiple heat transfer sections 617 have multiple fins 6171 and multiple flow paths 6172. The multiple fins 6171 extend along the +X direction and are arranged along the +Y direction. The multiple flow paths 6172 are flow paths through which the coolant can flow and are provided between the multiple fins 6171. The multiple first heat receiving plates 614 are arranged along the +X direction according to the upstream flow sections 6185 and the downstream flow sections 6186. The multiple heat transfer sections 617 are spaced apart from each other between the multiple first heat receiving plates 614 in the +X direction. The second light source unit 62 includes a second light source module 621 having a configuration similar to that of the first light source module 611, a plurality of second heat receiving plates 624 having a configuration similar to that of the plurality of first heat receiving plates 614, and a second cooling plate 625 having a configuration similar to that of the first cooling plate 615. That is, the second light source module 621 corresponds to a light source module, the plurality of second heat receiving plates 624 correspond to a plurality of heat receiving plates, and the second cooling plate 625 corresponds to a cooling plate.

[0071] With this configuration, compared to when a single heat transfer section is provided according to the length of the plurality of heat transfer sections 617 and gaps in the +X direction, the flow path 6172 along the +X direction can be shortened in each heat transfer section 617, thereby reducing pressure loss of the coolant. This allows the coolant to flow more easily through the plurality of heat transfer sections 617, thereby increasing the flow rate of the coolant in the first cooling plate 615 without using a large pump. This increases the cooling efficiency of the first cooling plate 615, which transfers heat from the first light source module 611 via the first heat receiving plate 614. The same applies to the second light source section 62, which includes the second light source module 621, the plurality of second heat receiving plates 624, and the second cooling plate 625.

[0072] Furthermore, the positions where the multiple heat transfer units 617 are spaced apart from one another correspond to the positions between the multiple first heat receiving plates 614 lined up in the +X direction. This allows the multiple heat transfer units 617 to be positioned at positions where heat is less likely to be transferred from the multiple first heat receiving plates 614 to the first cooling plate 615. In other words, heat can be more easily transferred from the multiple first heat receiving plates 614 to the multiple heat transfer units 617. Therefore, heat generated in the first light source module 611 can be more easily transferred to the multiple heat transfer units 617, and the multiple heat transfer units 617 transfer heat to the coolant, thereby improving the cooling efficiency of the first light source module 611. The same applies to the second light source unit 62.

[0073] As described above, the cooling liquid can be easily circulated through the first cooling plate 615 and the second cooling plate 625 without employing a large pump, which makes it possible to reduce the size of the projector 1. Furthermore, since the cooling efficiency of the first light source module 611 and the cooling efficiency of the second light source module 621 are increased, it is possible to easily increase the amount of light emitted from each of the light source modules 611, 621. Therefore, the brightness of the projected image can be increased.

[0074] In the light source device 4, the first cooling plate 615 includes a partition wall 6184 that extends in the +X direction and separates the internal space of the first cooling plate 615 into an upstream flow section 6185 and a downstream flow section 6186. With this configuration, the distance in the +Y direction between the upstream circulation section 6185 and the downstream circulation section 6186 can be shortened compared to when the upstream circulation section 6185 and the downstream circulation section 6186 are surrounded by different outer walls, and therefore the first cooling plate 615 and the second cooling plate 625 can be made smaller.

[0075] In the light source device 4, a plurality of heat transfer sections 617 are provided along the +X direction in each of the upstream circulation section 6185 and the downstream circulation section 6186. That is, the plurality of heat transfer sections 617 include a plurality of upstream heat transfer sections 617A arranged in the upstream circulation section 6185 and aligned in the +X direction, and a plurality of downstream heat transfer sections 617B arranged in the downstream circulation section 6186 and aligned in the +X direction. According to this configuration, the pressure loss of the coolant can be reduced in each of the upstream circulation section 6185 and the downstream circulation section 6186, and therefore, without using a large pump, it is possible to further improve the cooling efficiency of the first cooling plate 615 to which the heat of the first light source module 611 is transferred via the first heat receiving plate 614. The same applies to the second cooling plate 625. Furthermore, in the first light source unit 61, the heat generated in the first light source module 611 can be easily transferred to the plurality of heat transfer units 617 in each of the upstream circulation unit 6185 and the downstream circulation unit 6186, and therefore the plurality of heat transfer units 617 transfer heat to the coolant, thereby improving the cooling efficiency of the first light source module 611. The same applies to the second light source unit 62.

[0076] In the light source device 4, the multiple first heat receiving plates 614 include an upstream heat receiving plate 614A arranged corresponding to the upstream flow section 6185 and a downstream heat receiving plate 614B arranged corresponding to the downstream flow section 6186. With this configuration, the upstream heat receiving plate 614A can transfer heat from the base 612 on which the light emitting element 613 is arranged to the heat transfer section 617 (upstream heat transfer section 617A) arranged in the upstream circulation section 6185. Similarly, the downstream heat receiving plate 614B can transfer heat from the base 612 on which the light emitting element 613 is arranged to the heat transfer section 617 (downstream heat transfer section 617B) arranged in the downstream circulation section 6186. This makes it possible to easily transfer heat generated in the first light source module 611 to the cooling liquid flowing through the upstream circulation section 6185 and the downstream circulation section 6186 via the upstream heat transfer section 617A and the downstream heat transfer section 617B. Therefore, the cooling efficiency of the first light source module 611 can be improved. The same applies to the second light source section 62 having a configuration similar to that of the first light source section 61.

[0077] The first cooling plate 615 is a cooling plate through which a coolant can flow. The first cooling plate 615 includes an inlet portion 6181, an outlet portion 6182, an upstream circulation portion 6185, a downstream circulation portion 6186, and a plurality of heat transfer portions 617. The inlet portion 6181 is provided in the +Y direction (first direction), and the coolant flows into the inlet portion 6181. The outlet portion 6182 is provided in the -Y direction, and the coolant flows out. The coolant that flows in from the inlet portion 6181 flows in the +X direction (second direction) through the upstream circulation portion 6185. The coolant that has flowed through the upstream circulation portion 6185 flows in the -X direction through the downstream circulation portion 6186. The plurality of heat transfer portions 617 are arranged side by side in the +X direction in each of the upstream circulation portion 6185 and the downstream circulation portion 6186. The plurality of heat transfer units 617 include a plurality of fins 6171 and a plurality of flow paths 6172. The plurality of fins 6171 extend along the +X direction and are arranged along the +Y direction. The plurality of flow paths 6172 are provided between the plurality of fins 6171, and a coolant can flow through the plurality of flow paths 6172. The plurality of heat transfer units 617 are spaced apart from each other in the +X direction.

[0078] With this configuration, compared to when a single heat transfer portion is provided according to the length of the plurality of heat transfer portions 617 and gaps in the +X direction, the flow path 6172 along the +X direction in each heat transfer portion 617 can be made shorter, thereby reducing pressure loss of the coolant. This allows the coolant to flow more easily through the plurality of heat transfer portions 617, thereby increasing the flow rate of the coolant in the first cooling plate 615 without using a large pump. This increases the cooling efficiency of the first cooling plate 615. The same applies to the second cooling plate 625, which has a configuration similar to that of the first cooling plate 615.

[0079] [Modification of the first embodiment] In the light source section 6 described above, the first light source module 611 and the second light source module 621 have three upstream bases 612A and three downstream bases 612B. However, this is not limiting, and the number of upstream bases 612A and the number of downstream bases 612B included in the first light source module 611 can be changed as appropriate, and the number of upstream bases 612A and the number of downstream bases 612B included in the second light source module 621 can also be changed as appropriate.

[0080] FIG. 10 is a schematic diagram of a first light source section 61A, which is a modification of the first light source section 61, viewed from the light source light emission side. For example, a first light source section 61A shown in FIG. The first light source unit 61A includes a first light source module 611A, a plurality of first heat receiving plates 614, and a first cooling plate 615. The first light source unit 61A is provided with three first heat receiving plates 614, and the three first heat receiving plates 614 include two upstream heat receiving plates 614A and one downstream heat receiving plate 614B. Of the two upstream heat receiving plates 614A, one upstream heat receiving plate 614A is positioned corresponding to one of the three upstream heat transfer sections 617A in the -X direction, and the other upstream heat receiving plate 614A is positioned corresponding to one of the three upstream heat transfer sections 617A in the +X direction. One downstream heat receiving plate 614B is disposed corresponding to the central downstream heat transferring portion 617B in the +X direction among the three downstream heat transferring portions 617B.

[0081] The first light source module 611A emits light source light in the -Z direction. The first light source module 611A has a plurality of bases 612 on which light emitting elements 613 are provided. Specifically, the first light source module 611A includes a plurality of bases 612 including four upstream bases 612A and two downstream bases 612B. Of the four upstream substrates 612A, two upstream substrates 612A are arranged on the upstream heat receiving plate 614A in the -X direction, and the other two upstream substrates 612A are arranged on the upstream heat receiving plate 614A in the +X direction. The two downstream substrates 612B are arranged on one downstream heat receiving plate 614B. The light source device 4 having such a first light source unit 61A instead of the first light source unit 61 can also achieve the same effects as the light source device 4 having the first light source unit 61. Note that the second light source unit 62 may have the same configuration as the first light source unit 61A.

[0082] [Second embodiment] Next, a second embodiment of the present disclosure will be described. The projector according to this embodiment has a similar configuration to the projector 1 according to the first embodiment, but differs in that the configuration of the base provided in the light source device and the configuration of the heat receiving plate are different. Note that in the following explanation, parts that are the same or approximately the same as parts already explained will be assigned the same reference numerals and explanations thereof will be omitted.

[0083] [Outline of projector and light source device] FIG. 11 is a schematic diagram of the first light source section 64 of the light source device 4 provided in the projector according to this embodiment, viewed from the light source light emission side. The projector according to this embodiment has the same configuration and functions as the projector 1 according to the first embodiment, except that it has a first light source section 64 shown in Fig. 11 instead of the first light source section 61 according to the first embodiment. That is, the light source device 4 according to this embodiment has the same configuration and functions as the light source device 4 according to the first embodiment, except that it has a first light source section 64 instead of the first light source section 61 according to the first embodiment.

[0084] [Configuration of the first light source unit] The first light source unit 64 emits source light, which is blue light BLs, in the −Z direction, similar to the first light source unit 61. The first light source unit 64 includes a first light source module 641, a plurality of first heat receiving plates 644, and a first cooling plate 615.

[0085] [Configuration of the first light source module] The first light source module 641 includes a plurality of bases 642. In this embodiment, the first light source module 641 includes six bases 642 arranged in the +X direction. The plurality of bases 642 are arranged side by side in the +X direction, straddling the positions corresponding to the upstream flow section 6185 and the downstream flow section 6186 in the first cooling plate 615, respectively. Each of the multiple bases 642 supports multiple light-emitting elements 613 arranged in a matrix in the +X direction and the +Y direction. Specifically, a total of eight light-emitting elements 613 are arranged in one base 642, two in the +X direction and four in the +Y direction. Of the eight light-emitting elements 613 provided on one base 642, four light-emitting elements 613 in the +Y direction are arranged at positions corresponding to the upstream circulation section 6185, and four light-emitting elements 613 in the -Y direction are arranged at positions corresponding to the downstream circulation section 6186.

[0086] [Configuration of the first heat receiving plate] The multiple first heat receiving plates 644 are provided between the first light source module 641 and the first cooling plate 615, and support the respective bases 642. The dimension of the first heat receiving plates 644 in the +X direction is smaller than the dimension of the bases 642 in the +X direction. The multiple first heat receiving plates 644 are arranged side by side in the +X direction. Each of the multiple first heat receiving plates 644 is connected to an end portion in the +X direction of a corresponding one of the multiple bases 642. Specifically, the first heat receiving plate 644 disposed furthest in the +X direction is connected to the +X direction end of the base 642 disposed furthest in the +X direction. The first heat receiving plate 644 disposed furthest in the -X direction is connected to the -X direction end of the base 642 disposed furthest in the -X direction. The other first heat receiving plates 644 are disposed between two adjacent bases 642 so as to be connected to the -X direction end of the base 642 disposed in the +X direction and the +X direction end of the base 642 disposed in the -X direction. In other words, of the multiple light emitting elements 613 included in the first light source module 641, each first heat receiving plate 644 is disposed between two light emitting elements 613 adjacent to each other in the +X direction. In this way, each of the plurality of first heat receiving plates 644 is connected to the end portion of the corresponding one of the plurality of bases 642 in the +X direction.

[0087] Like the base 642, each of the multiple first heat receiving plates 644 is provided across a position on the first cooling plate 615 corresponding to the upstream circulation portion 6185 and a position on the downstream circulation portion 6186. The dimension of the first heat receiving plate 644 in the +Y direction is greater than the dimension of the base 642 in the +Y direction. Therefore, the end of the first heat receiving plate 644 in the +Y direction is located further in the +Y direction than the end of the corresponding base 642 in the +Y direction, and the end of the first heat receiving plate 644 in the -Y direction is located further in the -Y direction than the end of the corresponding base 642 in the -Y direction. In this embodiment, seven first heat receiving plates 644 are provided.

[0088] In such a first light source unit 64, the gaps GP1 and GP2 of the first cooling plate 615 are positioned between the multiple first heat receiving plates 644. That is, the multiple heat transfer units 617 are spaced apart between the multiple first heat receiving plates 644. More specifically, the gap GP1 in the -X direction is positioned between the second first heat receiving plate 644 and the third first heat receiving plate 644, counting from the -X direction. The gap GP1 in the +X direction is positioned between the second first heat receiving plate 644 and the third first heat receiving plate 644, counting from the +X direction. Similarly, the gap GP2 in the -X direction is positioned between the second first heat receiving plate 644 and the third first heat receiving plate 644, counting from the -X direction. The gap GP2 in the +X direction is positioned between the second first heat receiving plate 644 and the third first heat receiving plate 644, counting from the +X direction.

[0089] In this way, the gaps GP1 are positioned to separate the multiple upstream heat transfer sections 617A from one another, and the gaps GP2 are positioned to separate the multiple downstream heat transfer sections 617B from one another. This reduces the pressure loss of the coolant flowing through the upstream circulation section 6185 (see FIG. 5) and the downstream circulation section 6186 (see FIG. 5). In addition, heat from the multiple bases 642 can be efficiently transferred to the upstream heat transfer sections 617A and the downstream heat transfer sections 617B via the multiple first heat receiving plates 644. This facilitates the flow of the coolant and improves the cooling efficiency of the light emitting element 613 by the first cooling plate 615. The second light source unit 62 may have the same configuration as the first light source unit 64. In this case, the pressure loss of the coolant can be reduced also in the second light source unit 62, the coolant can be more easily circulated within the second cooling plate 625, and the cooling efficiency of the light emitting element 613 by the second cooling plate 625 can be improved. Due to pressure loss of the coolant, the plurality of heat transfer portions 617 are not spaced apart at corresponding positions between all of the plurality of first heat receiving plates 644 lined up in the +X direction. They are spaced apart from one another at positions corresponding to the spaces between predetermined first heat receiving plates 644. In other words, gaps GP1 do not have to be provided in correspondence with all of the positions between the plurality of first heat receiving plates 644 lined up in the +X direction. The positions at which the plurality of heat transfer sections 617 are spaced apart in the upstream heat transfer section 617A and the positions at which the plurality of heat transfer sections 617 are spaced apart in the downstream heat transfer section 617B are not limited to being the same positions, and may be different positions.

[0090] [Effects of the second embodiment] The projector according to this embodiment described above has the same effects as the projector 1 according to the first embodiment, and also has the following effects. The light source device 4 included in the projector according to this embodiment includes a light source section 6, and the light source section 6 includes a first light source section 64 and a second light source section 62. The first light source section 64 includes a first light source module 641 having a plurality of bases 642, a plurality of first heat receiving plates 644, and a first cooling plate 615. The multiple bases 642 are arranged side by side in the +X direction (second direction). Each of the multiple first heat receiving plates 644 is arranged side by side in the +X direction and connected to an end portion in the +X direction of a corresponding one of the multiple bases 642. The multiple first heat receiving plates 644 correspond to multiple heat receiving plates. According to this configuration, heat generated in the base 642 is transferred to the first cooling plate 615 via the first heat receiving plate 644 connected to the end of the base 642. Here, the multiple heat transfer units 617 are spaced apart from one another between the multiple first heat receiving plates 644 in the +X direction, and therefore the heat transfer units 617 are present at the connection portions of the first cooling plate 615 with the first heat receiving plates 644. Therefore, heat generated in the base 642 can be transferred to the heat transfer units 617 via the first heat receiving plate 644. This makes it possible to improve the cooling efficiency of the first light source module 641 having the multiple bases 642.

[0091] [Modification of the second embodiment] In the first light source unit 64 described above, the multiple first heat receiving plates 644 are connected to the end portions in the +X direction of each base 642. However, this is not limiting, and each first heat receiving plate 644 may be connected to the center portion in the +X direction of each base 642.

[0092] FIG. 12 is a schematic diagram of a first light source section 64A, which is a modification of the first light source section 64, viewed from the light source light emission side. For example, the first light source unit 64A shown in FIG. The first light source section 64A includes a plurality of first heat receiving plates 644A in addition to the same configuration as the first light source section 64. The first heat receiving plates 644A also correspond to heat receiving plates.

[0093] Like the first heat reception plate 644, each of the multiple first heat reception plates 644A supports the base 642 and transfers heat transferred from the base 642 to the first cooling plate 615. The multiple first heat reception plates 644A are provided between the multiple first heat reception plates 644. The dimension of the first heat reception plate 644A in the +X direction is the same as that of the first heat reception plate 644 in the +X direction, and the dimension of the first heat reception plate 644A in the +Y direction is the same as that of the first heat reception plate 644 in the +Y direction.

[0094] In such a first light source unit 64A, the gaps GP1 and GP2 between the plurality of heat transfer units 617 of the first cooling plate 615 are positioned at positions corresponding to the gap between the first heat receiving plate 644 and the first heat receiving plate 644A. That is, the plurality of heat transfer units 617 are spaced apart from one another in the portion corresponding to the gap between the first heat receiving plate 644 and the first heat receiving plate 644A.

[0095] More specifically, the gap GP1 in the -X direction is positioned between the second first heat receiving plate 644A and the third first heat receiving plate 644, counting from the -X direction. The gap GP1 in the +X direction is positioned between the second first heat receiving plate 644A and the third first heat receiving plate 644, counting from the +X direction. Thus, in this embodiment, the gap GP1 is located at a position corresponding to the light-emitting element 613, and the multiple upstream heat transfer sections 617A are spaced apart from one another at positions corresponding to the light-emitting element 613. In other words, the multiple heat transfer sections 617 arranged in the upstream circulation section 6185 are spaced apart from one another at positions that do not overlap with the light-emitting element 613.

[0096] Similarly, the gap GP2 in the -X direction is positioned between the second first heat receiving plate 644A and the third first heat receiving plate 644, counting from the -X direction. The gap GP2 in the +X direction is positioned between the second first heat receiving plate 644A and the third first heat receiving plate 644, counting from the +X direction. As described above, in this embodiment, the gap GP2 is located at a position corresponding to the light-emitting element 613, and the multiple downstream heat transfer portions 617B are spaced apart from one another at positions corresponding to the light-emitting element 613. In other words, the multiple heat transfer portions 617 arranged in the downstream circulation portion 6186 are spaced apart from one another at positions corresponding to the light-emitting element 613.

[0097] The light source device 4 including the first light source section 64A described above has the same effects as the light source device 4 including the first light source section 64, and also has the following effects. In the first light source section 64A included in the light source device 4, the plurality of heat transfer sections 617 are spaced apart from one another at positions where they do not overlap with the light emitting elements 613. With this configuration, even if the heat transfer sections 617 are spaced apart from one another at positions corresponding to the light emitting elements 613, the heat of the bases 642 can be transferred to the heat transfer sections 617 via the first heat receiving plates 644, 644A. This makes it easy to arbitrarily set the number of light emitting elements 613 arranged on the base 642, and also increases the degree of freedom in the layout of the light emitting elements 613 on the base 642. This increases the degree of freedom in the design of the first light source module 641. The second light source unit 62 may have the same configuration as the first light source unit 61 A. The first light source unit 64 may not have the multiple first heat receiving plates 644, but may have the multiple first heat receiving plates 644 A.

[0098] [Third embodiment] Next, a third embodiment of the present disclosure will be described. The projector according to this embodiment has the same configuration as the projector according to the second embodiment, but differs in the configuration of the heat receiving plate that transfers heat generated in the multiple bases 642 to the first cooling plate 615. In the following explanation, parts that are the same or approximately the same as parts that have already been explained will be assigned the same reference numerals and explanations thereof will be omitted.

[0099] [Outline of projector and light source device] FIG. 13 is a schematic diagram of the first light source section 65 of the light source device 4 provided in the projector according to this embodiment, viewed from the light source light emission side. The projector according to this embodiment has the same configuration and functions as the projector 1 according to the first embodiment, except that it has a first light source section 65 shown in Fig. 13 instead of the first light source section 61 according to the first embodiment. That is, the light source device 4 according to this embodiment has the same configuration and functions as the light source device 4 according to the first embodiment, except that it has a first light source section 65 instead of the first light source section 61.

[0100] [Configuration of the first light source unit] Similar to the first light source unit 61, the first light source unit 65 emits light source light, which is blue light BLs, in the -Z direction. The first light source unit 65 includes a first light source module 641, a first heat receiving plate 654, and a first cooling plate 655. That is, in this embodiment, the first light source unit 65 includes one first heat receiving plate 654. As described above, the first light source module 641 includes a plurality of bases 642 arranged in the +X direction, and each of the plurality of bases 642 has a plurality of light-emitting elements 613 arranged in a matrix along the +X direction and the +Y direction.

[0101] [Configuration of the first heat receiving plate] The first heat receiving plate 654 corresponds to a heat receiving plate. The first heat receiving plate 654 is formed larger than the first light source module 641 when viewed from the -Z direction, and supports a plurality of bases 642. The first heat receiving plate 654 is disposed across the upstream circulation portion 6185 and the downstream circulation portion 6186 of the first cooling plate 615.

[0102] [Configuration of the first cooling plate] Similar to the first cooling plate 615 according to the first embodiment, the first cooling plate 655 cools the plurality of light-emitting elements 613 by transferring heat from the plurality of light-emitting elements 613 transferred from the plurality of bases 642 via the first heat receiving plate 654 to the cooling liquid flowing inside. The first cooling plate 655 has the same configuration and function as the first cooling plate 615. However, while the first cooling plate 615 has a plurality of heat transfer sections 617 including three upstream heat transfer sections 617A and three downstream heat transfer sections 617B, the first cooling plate 655 has a plurality of heat transfer sections 617 including two upstream heat transfer sections 617A and two downstream heat transfer sections 617B. The inlet portion 6181 of the first cooling plate 655 is provided at an end 655A of the first cooling plate 655 in the -X direction, in a portion in the +Y direction along the end 655A. The outlet portion 6182 of the first cooling plate 655 is provided at an end 655A in the -Y direction relative to the portion in the +Y direction where the inlet portion 6181 is provided. The end 618B of the second plate element 618 constitutes the end 655A.

[0103] In the first light source unit 65, gaps GP1 and GP2 between the multiple heat transfer units 617 of the first cooling plate 615 are positioned at positions corresponding to the gap between two adjacent bases 642 in the +X direction. More specifically, the gaps GP1 and GP2 are positioned at positions corresponding to the gap between the light emitting elements 613 included in two adjacent bases 642 in the +X direction among the multiple bases 642. That is, the multiple heat transfer units 617 are provided on the two adjacent bases 642 in the +X direction, and are spaced apart from each other at positions corresponding to the gap between the two adjacent light emitting elements 613 in the +X direction.

[0104] Specifically, the gap GP1 between the two upstream heat transfer portions 617A is located at a position corresponding to the gap between the two bases 642 located at the center in the +X direction. That is, the two upstream heat transfer portions 617A are spaced apart at a position corresponding to the gap between the two bases 642 located at the center in the +X direction. In other words, the two upstream heat transfer portions 617A are spaced apart at a position corresponding to the gap between the light emitting element 613 located in the +X direction on the −X direction base 642 and the light emitting element 613 located in the −X direction on the +X direction base 642, of the two bases 642 located at the center in the +X direction.

[0105] Similarly, the gap GP2 between the two downstream heat transfer portions 617B is located at a position corresponding to the gap between the two bases 642 located at the center in the +X direction. That is, the two downstream heat transfer portions 617B are spaced apart at a position corresponding to the gap between the two bases 642 located at the center in the +X direction. In other words, the two downstream heat transfer portions 617B are spaced apart at a position corresponding to the gap between the light emitting element 613 located in the +X direction on the −X direction base 642 and the light emitting element 613 located in the −X direction on the +X direction base 642, of the two bases 642 located at the center in the +X direction.

[0106] Positioning the gaps GP1 and GP2 in this manner reduces pressure loss of the coolant flowing through the upstream circulation portion 6185 and the downstream circulation portion 6186, and also enables efficient transfer of heat from the plurality of bases 642 to the upstream heat transfer portion 617A and the downstream heat transfer portion 617B via the first heat receiving plate 654. Therefore, the coolant can flow more easily, and the cooling efficiency of the light emitting element 613 by the first cooling plate 655 can be improved.

[0107] The positions where the gaps GP1 and GP2 are set do not have to be between the same two base bodies 642. For example, the gap GP1 may be positioned at a position corresponding to between the second and third base bodies 642 counting from the +X direction, and the gap GP2 may be positioned at a position corresponding to between the fourth and fifth base bodies 642 counting from the +X direction. Furthermore, for example, one of the gaps GP1 and GP2 may be disposed at a position corresponding to the gap between two light emitting elements 613 adjacent to each other in the +X direction on one base 642.

[0108] [Effects of the third embodiment] The projector according to this embodiment described above has the same effects as the projector 1 according to the first embodiment. That is, the light source device 4 included in the projector according to this embodiment includes a light source section 6, and the light source section 6 includes a first light source section 65 and a second light source section 62. The first light source section 65 includes a first light source module 641, one first heat receiving plate 654, and a first cooling plate 655. The first light source module 641 corresponds to a light source module. The first light source module 641 has a plurality of bases 642 on which light emitting elements 613 are arranged. The first heat receiving plate 654 corresponds to a heat receiving plate, and is connected to the first light source module 641. The first cooling plate 655 corresponds to a cooling plate, and is connected to the first heat receiving plate 654. A coolant flows inside the first cooling plate 655.

[0109] The first cooling plate 655 includes an inlet portion 6181, an outlet portion 6182, an upstream circulation portion 6185, a downstream circulation portion 6186, and a plurality of heat transfer portions 617. The inlet portion 6181 is provided in a portion in the +Y direction (first direction) along the end portion 618B, and the coolant flows into the inlet portion 6181. The outlet portion 6182 is provided in a portion in the -Y direction relative to the +Y direction portion where the inlet portion 6181 is provided on the end portion 618B, and the coolant flows out from the outlet portion 6182. In the upstream circulation portion 6185, the coolant that flows in from the inlet portion 6181 flows in the +X direction (second direction). In the downstream circulation portion 6186, the coolant that has flowed through the upstream circulation portion 6185 flows in the -X direction. The plurality of heat transfer sections 617 are provided in each of the upstream circulation section 6185 and the downstream circulation section 6186 and are arranged side by side in the +X direction. The plurality of heat transfer sections 617 include a plurality of fins 6171 and a plurality of flow paths 6172. The plurality of fins 6171 extend along the +X direction and are arranged along the +Y direction. The plurality of flow paths 6172 are provided between the plurality of fins 6171 and are flow paths through which a coolant can flow. The plurality of bases 642 are arranged side by side in the +X direction. Each of the plurality of heat transfer sections 617 is spaced apart from one another at a position corresponding to a gap between two of the plurality of light emitting elements 613 arranged side by side in the +X direction. In other words, each of the plurality of heat transfer sections 617 is spaced apart from one another at a position that does not overlap with two of the plurality of light emitting elements 613 arranged side by side in the +X direction.

[0110] According to this configuration, similar to the first cooling plate 615, it is possible to reduce the pressure loss of the coolant flowing through the first cooling plate 655. Therefore, the coolant can easily flow through the multiple heat transfer portions 617, and the flow rate of the coolant in the first cooling plate 655 can be increased without using a large pump. Therefore, it is possible to improve the cooling efficiency of the first cooling plate 655, to which the heat of the first light source module 641 is transferred via the first heat receiving plate 654. Furthermore, the positions where the plurality of heat transfer sections 617 are spaced apart from one another can be positioned at positions where heat is less likely to be transferred from the plurality of light emitting elements 613 to the first cooling plate 655, making it possible to easily transfer heat from the plurality of light emitting elements 613 to the plurality of heat transfer sections 617. Therefore, the cooling efficiency of the first light source module 641 can be improved.

[0111] The second light source unit 62 may have the same configuration as the first light source unit 65. In this case, the pressure loss of the coolant can be reduced also in the second light source unit 62, the coolant can be more easily circulated within the second cooling plate 625, and the cooling efficiency of the light emitting element 613 by the second cooling plate 625 can be improved. Furthermore, the positions of the gaps GP1 and GP2 may be different. That is, as long as two adjacent upstream heat transfer portions 617A in the +X direction are spaced apart between two adjacent bases 642 or two adjacent light-emitting elements 613 in the +X direction, the position of the gap GP1 and the number of the upstream heat transfer portions 617A are not important. Similarly, as long as two adjacent downstream heat transfer portions 617B in the +X direction are spaced apart between two adjacent bases 642 or two adjacent light-emitting elements 613 in the +X direction, the position of the gap GP2 and the number of the downstream heat transfer portions 617B are not important.

[0112] [Fourth embodiment] Next, a fourth embodiment of the present disclosure will be described. The projector according to this embodiment has a similar configuration to the projector 1 according to the first embodiment, but differs in that it is provided with a heat receiving plate corresponding to the upstream flow section of the cooling plate and a heat receiving plate corresponding to the downstream flow section. Note that in the following explanation, parts that are the same or approximately the same as parts already explained will be given the same reference numerals and explanations thereof will be omitted.

[0113] [Outline of projector and light source device] FIG. 14 is a schematic diagram of the first light source section 66 of the light source device 4 provided in the projector according to this embodiment, viewed from the light source light emission side. The projector according to this embodiment has the same configuration and functions as the projector 1 according to the first embodiment, except that it has a first light source section 66 shown in Fig. 14 instead of the first light source section 61 according to the first embodiment. That is, the light source device 4 according to this embodiment has the same configuration and functions as the light source device 4 according to the first embodiment, except that it has a first light source section 66 instead of the first light source section 61 according to the first embodiment.

[0114] [Configuration of the first light source unit] The first light source unit 66 emits source light, which is blue light BLs, in the −Z direction, similar to the first light source unit 61. The first light source unit 66 includes a first light source module 661, a plurality of first heat receiving plates 664, and a first cooling plate 615.

[0115] [Configuration of the first light source module] The first light source module 661 includes a plurality of bases 662 arranged in the +X direction, and each of the plurality of bases 662 has a plurality of light-emitting elements 613 arranged in a matrix along the +X direction and the +Y direction. In this embodiment, each of the plurality of bases 662 has two light-emitting elements 613 in the +X direction and two light-emitting elements 613 in the +Y direction, for a total of four light-emitting elements 613. The multiple substrates 662 include multiple upstream substrates 662A arranged in the +X direction according to the upstream flow section 6185 of the first cooling plate 615, and multiple downstream substrates 662B arranged in the +X direction according to the downstream flow section 6186. In this embodiment, the number of upstream substrates 662A is six, and the number of downstream substrates 662B is six.

[0116] [Configuration of the first heat receiving plate] The multiple first heat receiving plates 664 support the multiple bases 662 and transfer heat transferred from the multiple bases 662 to the first cooling plate 615. The multiple first heat receiving plates 664 include one upstream heat receiving plate 664A arranged on the first surface 616A in accordance with the upstream flow section 6185 of the first cooling plate 615, and one downstream heat receiving plate 664B arranged on the first surface 616A in accordance with the downstream flow section 6186. The upstream heat receiving plate 664A supports the six upstream bases 662A. When viewed from the -Z direction, the upstream heat receiving plate 664A is larger than the six upstream bases 662A and smaller than the upstream flow portion 6185. The downstream heat receiving plate 664B supports the six downstream bases 662B. When viewed from the -Z direction, the downstream heat receiving plate 664B is larger than the six downstream bases 662B and smaller than the downstream flow portion 6186.

[0117] In the first light source unit 66, the gaps GP1 and GP2 between the multiple heat transfer units 617 of the first cooling plate 615 are positioned at positions corresponding to the gaps between the light emitting elements 613 of one of the multiple bases 662. That is, the multiple heat transfer units 617 are spaced apart from each other at positions corresponding to the gaps between two light emitting elements 613 adjacent to each other in the +X direction on one base 662.

[0118] More specifically, the gap GP1 in the -X direction is positioned at a position on the second upstream base 662A counting from the -X direction, corresponding to a gap between two adjacent light-emitting elements 613 in the +X direction. That is, the two upstream heat transfer sections 617A in the -X direction are spaced apart from each other at positions on the second upstream base 662A counting from the -X direction, corresponding to a gap between two adjacent light-emitting elements 613 in the +X direction. Furthermore, the gap GP1 in the +X direction is positioned at a position corresponding to the gap between two adjacent light-emitting elements 613 in the +X direction on the second upstream base 662A counting from the +X direction. That is, the two upstream heat transfer sections 617A in the +X direction are spaced apart from each other at positions corresponding to the gap between two adjacent light-emitting elements 613 in the +X direction on the second upstream base 662A counting from the +X direction.

[0119] The two gaps GP2 between the three downstream heat transfer portions 617B are positioned similarly to the two gaps GP1, i.e., the positions at which the three downstream heat transfer portions 617B are spaced apart are also similar to the positions at which the three upstream heat transfer portions 617A are spaced apart. Positioning the gaps GP1 and GP2 in this manner reduces pressure loss of the coolant flowing through the upstream circulation portion 6185 and the downstream circulation portion 6186. In addition, heat from the multiple upstream bases 662A can be efficiently transferred to the upstream heat transfer portion 617A via the upstream heat receiving plate 664A, and heat from the multiple downstream bases 662B can be efficiently transferred to the downstream heat transfer portion 617B via the downstream heat receiving plate 664B. This allows the coolant to flow more easily and improves the cooling efficiency of the light emitting element 613 by the first cooling plate 615.

[0120] In this embodiment, the positions where two adjacent heat transfer portions 617 are spaced apart in the +X direction, i.e., the positions of the gaps GP1 and GP2, correspond to the positions between adjacent light emitting elements 613 in the +X direction. However, the present invention is not limited to this, and the positions of the gaps GP1 and GP2 may also correspond to the positions between adjacent bases 662 in the +X direction.

[0121] [Effects of the fourth embodiment] The projector according to this embodiment described above has the same effects as the projector 1 according to the first embodiment. That is, the light source device 4 included in the projector according to this embodiment includes a light source section 6, and the light source section 6 includes a first light source section 66 and a second light source section 62. The first light source section 66 includes a first light source module 661, a plurality of first heat receiving plates 664, and a first cooling plate 615. The first light source module 661 corresponds to a light source module. The first light source module 661 has a plurality of bases 662 on which light emitting elements 613 are arranged. The plurality of first heat receiving plates 664 correspond to heat receiving plates and are connected to the first light source module 661. The first cooling plate 615 corresponds to a cooling plate and is connected to the plurality of first heat receiving plates 664. A coolant flows inside the first cooling plate 615.

[0122] The first cooling plate 615 is connected to each of the multiple first heat receiving plates 614, and coolant flows through the first cooling plate 615. The first cooling plate 615 includes an inlet portion 6181, an outlet portion 6182, an upstream circulation portion 6185, a downstream circulation portion 6186, and multiple heat transfer portions 617. The inlet portion 6181 is provided in a portion in the +Y direction (first direction) along the end portion 618B, and the coolant flows into the inlet portion 6181. The outlet portion 6182 is provided in a portion in the -Y direction of the end portion 618B relative to the +Y direction portion where the inlet portion 6181 is provided, and the coolant flows out from the outlet portion 6182. The coolant that flows in from the inlet portion 6181 flows in the +X direction (second direction) through the upstream circulation portion 6185. The coolant that has flowed through the upstream circulation portion 6185 flows in the -X direction through the downstream circulation portion 6186. A plurality of heat transfer sections 617 are provided in each of the upstream flow section 6185 and the downstream flow section 6186, and are arranged side by side in the +X direction. The multiple first heat receiving plates 664 include an upstream heat receiving plate 664A provided in accordance with the upstream flow section 6185 and a downstream heat receiving plate 664B provided in accordance with the downstream flow section 6186. The multiple bases 662 include multiple upstream bases 662A arranged side by side in the +X direction and connected to the upstream heat receiving plate 664A, and multiple downstream bases 662B arranged side by side in the +X direction and connected to the downstream heat receiving plate 664B. Each of the multiple heat transfer sections 617 is spaced apart between two adjacent light emitting elements 613 in the +X direction among the multiple light emitting elements 613. In other words, each of the multiple heat transfer sections 617 is spaced apart at a position where it does not overlap with two adjacent light emitting elements 613 in the +X direction among the multiple light emitting elements 613 arranged side by side in the +X direction.

[0123] This configuration reduces pressure loss of the coolant flowing through the first cooling plate 615. This allows the coolant to flow more easily through the multiple heat transfer sections 617, thereby increasing the flow rate of the coolant in the first cooling plate 615 without using a large pump. This therefore increases the cooling efficiency of the first cooling plate 615, to which heat from the first light source module 661 is transferred via the first heat receiving plate 664. Furthermore, the positions where the multiple heat transfer units 617 are spaced apart are between the multiple light emitting elements 613 lined up in the +X direction. This allows the positions where the multiple heat transfer units 617 are spaced apart, i.e., the gaps GP1 and GP2, to be positioned at positions where heat is less likely to be transferred from the multiple light emitting elements 613 to the first cooling plate 615. In other words, because the heat transfer units 617 are arranged corresponding to the light emitting elements 613, it is possible to facilitate the transfer of heat from the multiple light emitting elements 613 to the multiple heat transfer units 617. Therefore, it is possible to facilitate the transfer of heat generated in the first light source module 661 to the multiple heat transfer units 617, and it is possible to improve the cooling efficiency of the first light source module 661. Furthermore, heat from the multiple upstream substrates 662A is transferred to the upstream circulation section 6185 via the upstream heat receiving plate 664A, and heat from the multiple downstream substrates 662B is transferred to the downstream circulation section 6186 via the downstream heat receiving plate 664B. This makes it easier to transfer heat generated in the first light source module 661 to the coolant flowing through the upstream circulation section 6185 and the downstream circulation section 6186, compared to when the heat from the multiple upstream substrates 662A and the heat from the multiple downstream substrates 662B are collectively transferred to one of the upstream circulation section 6185 and the downstream circulation section 6186. Therefore, the cooling efficiency of the first light source module 661 can be further improved.

[0124] [Modification of the embodiment] The present disclosure is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present disclosure are included in the present disclosure. In each of the above embodiments, the light source device 4 includes one of the first light source units 61, 61A, 64, 64A, 65, and 66, the second light source unit 62, and the light combining member 63. However, this is not limited thereto, and the light source device according to the present disclosure may include the first light source unit without including the second light source unit and the light combining member. Alternatively, the light source device may include, in addition to the first light source unit, the second light source unit, and the light combining member, a third light source unit having a configuration similar to one of the first light source unit and the second light source unit. Furthermore, among the multiple light source units included in the light source device, at least one light source unit may have a configuration similar to one of the first light source units 61, 61A, 64, 64A, 65, and 66, and the remaining light source units may have a configuration similar to the other one of the first light source units 61, 61A, 64, 64A, 65, and 66.

[0125] In the above embodiments, the number of upstream heat transfer sections 617A arranged in the upstream circulation section 6185 among the multiple heat transfer sections 617 is two or three, and the number of downstream heat transfer sections 617B arranged in the downstream circulation section 6186 is two or three. However, the number of upstream heat transfer sections 617A may be two or more, and the number of downstream heat transfer sections 617B may be two or more. The number of bases included in the light source module may also be changed as appropriate, and the number of light-emitting elements provided on the bases may also be changed as appropriate. For example, four light-emitting elements may be mounted on one of the bases 612 shown in the first embodiment, the base 612 shown in the modified first embodiment, and the base 662 shown in the fourth embodiment in a +Y direction or a −Y direction. Alternatively, four light-emitting elements may be mounted on one of the bases 612, 642, and 662 shown in the above embodiments in a +X direction or a −X direction, instead of one or two.

[0126] In each of the above-described embodiments, the multiple heat transfer sections 617 aligned in the +X direction are provided in each of the upstream circulation section 6185 and the downstream circulation section 6186. However, this is not limiting, and the multiple heat transfer sections 617 may be provided in only one of the circulation sections, the upstream circulation section 6185 and the downstream circulation section 6186.

[0127] In each of the above embodiments, the first cooling plate 615, 655 and the second cooling plate 625 have the partition wall 6184 that divides the space within the recess 6183 into an upstream circulation portion 6185 and a downstream circulation portion 6186. However, this is not limiting, and the partition wall 6184 may be omitted. For example, the cooling module may be formed in a U-shape, and the upstream portion of the internal space of the cooling module may be the upstream circulation portion and the downstream portion may be the downstream circulation portion.

[0128] In the first embodiment, two bases 612 aligned in the +X direction are supported by one first heat receiving plate 614. In the second embodiment, one base 642 is supported by two first heat receiving plates 644, or two first heat receiving plates 644 and one first heat receiving plate 644A. In the third embodiment, all of the bases 642 are supported by one first heat receiving plate 654. In the fourth embodiment, six bases 612 aligned in the +X direction are supported by an upstream heat receiving plate 664A or a downstream heat receiving plate 664B. However, this is not a limitation, and the number of bases supported by one heat receiving plate can be changed as appropriate, and the number of heat receiving plates supporting one base can be changed as appropriate.

[0129] In the above-described embodiments, the bases 612, 642, 662 on which the light emitting elements 613 are provided and the first heat receiving plates 614, 644, 654, 664 are arranged corresponding to the upstream circulation portion 6185 and the downstream circulation portion 6186. However, the present invention is not limited to this, and a base and a heat receiving plate may be provided corresponding to only one of the upstream circulation portion 6185 and the downstream circulation portion 6186.

[0130] In each of the above embodiments, the light source device 4 has the configuration and layout shown in Fig. 2. However, the configuration and layout of the light source device of the present disclosure are not limited to the above example. The same applies to a projector equipped with the light source device of the present disclosure.

[0131] In the above embodiments, the image forming device 34 includes three light modulation devices 343B, 343G, and 343R. However, the present disclosure is not limited to this and can also be applied to a projector including an image forming device having two or less light modulation devices, or four or more light modulation devices. In each of the above embodiments, the light modulation device 343 has a transmissive liquid crystal panel with a light incident surface and a light exit surface that are different from each other. However, the light modulation device provided in the projector of the present disclosure is not limited to this, and may have a configuration with a reflective liquid crystal panel with a light incident surface and a light exit surface that are the same. Furthermore, a light modulation device other than a liquid crystal device, such as a device using a micromirror such as a DMD (Digital Micromirror Device), may be used in the projector as long as it is capable of modulating an incident light beam to form an image according to image information.

[0132] In the above-described embodiments, the light source device according to the present disclosure is applied to a projector. However, the present disclosure is not limited to this, and may be applied to electronic devices other than projectors, such as lighting devices and headlights of automobiles.

[0133] In the above-described embodiments, the cooling plate is used to cool the light-emitting element provided on the base body. However, the present disclosure is not limited to this, and the cooling plate may be used to cool other cooling targets.

[0134] Summary of this disclosure A summary of this disclosure is provided below. A light source device according to a first aspect of the present disclosure includes a light source module having a plurality of bases on which light emitting elements are arranged, a plurality of heat receiving plates connected to the light source module, and a cooling plate connected to each of the plurality of heat receiving plates and through which a coolant flows, the cooling plate having an inlet portion provided at a portion in a first direction along an end portion and through which the coolant flows, an outlet portion provided at a portion in a direction opposite to the first direction with respect to the portion and through which the coolant flows out, an upstream circulation portion through which the coolant flowing in from the inlet portion flows in a second direction perpendicular to the first direction, and the coolant having flowed through the upstream circulation portion flows in the second direction. and a downstream circulation section in which the cooling liquid flows in the opposite direction to the upstream circulation section, and a plurality of heat transfer sections provided in at least one of the circulation sections of the upstream circulation section and the downstream circulation section and arranged side by side in the second direction, wherein the plurality of heat transfer sections extend along the second direction and have a plurality of fins arranged along the first direction and a plurality of flow paths provided between the plurality of fins and through which the cooling liquid can flow, and the plurality of heat receiving plates are arranged along the second direction according to the at least one circulation section, and each of the plurality of heat transfer sections is spaced apart from one another at positions corresponding to the spaces between the plurality of heat receiving plates in the second direction.

[0135] With this configuration, compared to when a single heat transfer section is provided corresponding to the lengths of the multiple heat transfer sections in the second direction, the flow path of the coolant in each heat transfer section can be shortened, thereby reducing the pressure loss of the coolant. This allows the coolant to flow more easily through the multiple heat transfer sections, thereby increasing the flow rate of the coolant in the cooling plate without using a large pump. Therefore, the cooling efficiency of the cooling plate, which transfers heat from the light source module via the heat receiving plate, can be improved. Furthermore, the positions where the multiple heat transfer units are spaced apart are between the multiple heat receiving plates lined up in the second direction. This allows the positions where the multiple heat transfer units are spaced apart to be positioned so that heat is less likely to be transferred from the multiple heat receiving plates to the cooling plate. In other words, it is possible to facilitate heat transfer from the multiple heat receiving plates to the multiple heat transfer units. Therefore, it is possible to facilitate transfer of heat generated in the light source module to the multiple heat transfer units, and the multiple heat transfer units transfer heat to the coolant, thereby improving the cooling efficiency of the light source module.

[0136] In the first aspect, the cooling plate may include a partition wall that extends in the second direction and divides an internal space of the cooling plate into the upstream flow portion and the downstream flow portion. With this configuration, the distance in the first direction between the upstream circulation section and the downstream circulation section can be made shorter than when the upstream circulation section and the downstream circulation section are surrounded by different outer walls, thereby making it possible to reduce the size of the cooling plate.

[0137] In the first aspect, the plurality of heat transfer sections may be provided in each of the upstream circulation section and the downstream circulation section. With this configuration, the pressure loss of the cooling liquid can be reduced in both the upstream circulation section and the downstream circulation section, thereby increasing the cooling efficiency of the cooling plate, to which heat from the light source module is transferred via the heat receiving plate, without using a large pump. In addition, in each of the upstream circulation section and the downstream circulation section, it is possible to easily transfer heat generated in the light source module to multiple heat transfer sections, and as the multiple heat transfer sections transfer heat to the cooling liquid, the cooling efficiency of the light source module can be improved.

[0138] In the first aspect, the plurality of heat receiving plates may include an upstream heat receiving plate arranged corresponding to the upstream flow portion, and a downstream heat receiving plate arranged corresponding to the downstream flow portion. According to this configuration, the upstream heat receiving plate can transfer heat from the base on which the light-emitting element is disposed to at least one of the heat transfer sections arranged in the upstream circulation section. Similarly, the downstream heat receiving plate can transfer heat from the base on which the light-emitting element is disposed to at least one of the heat transfer sections arranged in the downstream circulation section. This makes it easier for the heat generated in the light source module to be transferred to the coolant flowing through each of the upstream circulation section and the downstream circulation section by the heat transfer section arranged in the upstream circulation section and the heat transfer section arranged in the downstream circulation section. Therefore, the cooling efficiency of the light source module can be improved.

[0139] In the first aspect, the plurality of bases may be arranged in a line in the second direction, and each of the plurality of heat receiving plates may be arranged in a line in the second direction and connected to an end of a corresponding one of the plurality of bases in the second direction. According to this configuration, heat generated in the base is transferred to the cooling plate via the heat receiving plate connected to the end of the base. Here, since the heat transfer units are spaced apart from one another between the heat receiving plates in the second direction, the heat transfer units are present at the connection points of the cooling plate with the heat receiving plates, allowing the heat generated in the base to be transferred to the heat transfer units via the heat receiving plate. This improves the cooling efficiency of a light source module having multiple bases.

[0140] In the first aspect, the plurality of heat transfer parts may be spaced apart from one another at positions where they do not overlap with the light emitting element. With this configuration, even if the heat transfer units are spaced apart so as not to overlap the light emitting elements provided on the base, the heat of the base can be transferred to the heat transfer units via the heat receiving plates. This makes it easier to set the number of light emitting elements provided on the base as desired, and also increases the degree of freedom in the layout of the light emitting elements on the base. Therefore, the degree of freedom in the design of the light source module can be increased.

[0141] A light source device according to a second aspect of the present disclosure includes a light source module having a plurality of bases on which light emitting elements are arranged, one heat receiving plate connected to the light source module, and a cooling plate connected to the heat receiving plate and through which a coolant flows, the cooling plate having an inlet portion provided at a portion in a first direction along an end portion and through which the coolant flows, an outlet portion provided at a portion in a direction opposite to the first direction with respect to the portion and through which the coolant flows out, an upstream circulation portion through which the coolant that flows in from the inlet portion flows in a second direction perpendicular to the first direction, and an outlet portion through which the coolant that has flowed through the upstream circulation portion flows in the second direction. and a plurality of heat transfer parts provided in at least one of the upstream and downstream circulation parts and arranged side by side in the second direction, wherein the plurality of heat transfer parts extend along the second direction and have a plurality of fins arranged along the first direction, and a plurality of flow paths provided between the plurality of fins and through which the coolant can flow, the plurality of bases are arranged side by side in the second direction, and each of the plurality of heat transfer parts is spaced apart from one another at a position corresponding to between two of the plurality of light-emitting elements arranged side by side in the second direction.

[0142] According to this configuration, it is possible to achieve the same effects as the light source device according to the first aspect described above. In other words, compared to when a single heat transfer section is provided corresponding to the lengths of the plurality of heat transfer sections in the second direction, the flow path of the coolant in each heat transfer section can be shortened, thereby reducing the pressure loss of the coolant. This allows the coolant to flow more easily through the plurality of heat transfer sections, thereby increasing the flow rate of the coolant in the cooling plate without using a large pump and improving the cooling efficiency of the cooling plate, which transfers heat from the light source module via the heat receiving plate. Furthermore, the positions where the multiple heat transfer units are spaced apart are between the multiple light-emitting elements lined up in the second direction. This allows the positions where the multiple heat transfer units are spaced apart to be positioned so that heat is less likely to be transferred from the multiple light-emitting elements to the cooling plate. In other words, because the heat transfer units are arranged corresponding to the light-emitting elements, it is possible to facilitate the transfer of heat from the light-emitting elements to the multiple heat transfer units. Therefore, it is possible to facilitate the transfer of heat generated in the light source module to the multiple heat transfer units, and the multiple heat transfer units transfer heat to the coolant, thereby improving the cooling efficiency of the light source module.

[0143] A light source device according to a third aspect of the present disclosure includes a light source module having a plurality of bases on which light emitting elements are arranged, a plurality of heat receiving plates connected to the light source module, and a cooling plate connected to each of the plurality of heat receiving plates and through which a coolant flows, the cooling plate having an inlet portion provided in a portion in a first direction along an end portion and through which the coolant flows, an outlet portion provided in a portion in a direction opposite to the first direction with respect to the portion and through which the coolant flows out, an upstream circulation portion through which the coolant flowing in from the inlet portion flows in a second direction perpendicular to the first direction, a downstream circulation portion through which the coolant having flowed through the upstream circulation portion flows in a direction opposite to the second direction, and a plurality of cooling plates provided in at least one circulation portion of the upstream circulation portion and the downstream circulation portion and provided along the second direction. and a heat transfer section in which the plurality of heat transfer sections extend along the second direction and have a plurality of fins arranged along the first direction, and a plurality of flow paths provided between the plurality of fins and through which the coolant can flow, the plurality of bases are arranged in a line in the second direction, and the plurality of heat receiving plates include an upstream heat receiving plate provided in accordance with the upstream flow section and a downstream heat receiving plate provided in accordance with the downstream flow section, the plurality of bases include a plurality of upstream bases arranged in a line in the second direction and connected to the upstream heat receiving plate, and a plurality of downstream bases arranged in a line in the second direction and connected to the downstream heat receiving plate, and each of the plurality of heat transfer sections is spaced apart from each other at a position corresponding to between two of the plurality of light-emitting elements arranged in the second direction.

[0144] According to this configuration, it is possible to achieve the same effects as the light source devices according to the first and second aspects described above. In other words, compared to when a single heat transfer section is provided corresponding to the lengths of the plurality of heat transfer sections in the second direction, the flow path of the coolant in each heat transfer section can be shortened, thereby reducing the pressure loss of the coolant. This allows the coolant to flow more easily through the plurality of heat transfer sections, thereby increasing the flow rate of the coolant in the cooling plate without using a large pump and improving the cooling efficiency of the cooling plate, which transfers heat from the light source module via the heat receiving plate. Furthermore, the positions where the multiple heat transfer units are spaced apart are between the multiple light-emitting elements lined up in the second direction. This allows the positions where the multiple heat transfer units are spaced apart to be positioned so that heat is less likely to be transferred from the multiple light-emitting elements to the cooling plate. In other words, because the heat transfer units are arranged corresponding to the light-emitting elements, it is possible to facilitate the transfer of heat from the light-emitting elements to the multiple heat transfer units. Therefore, it is possible to facilitate the transfer of heat generated in the light source module to the multiple heat transfer units, and the multiple heat transfer units transfer heat to the coolant, thereby improving the cooling efficiency of the light source module. Furthermore, heat from the multiple upstream substrates is transferred to the upstream circulation section via the upstream heat receiving plate, and heat from the multiple downstream substrates is transferred to the downstream circulation section via the downstream heat receiving plate. This makes it easier to transfer heat generated in the light source module to the coolant flowing through the upstream circulation section and the downstream circulation section, compared to when the heat from the multiple upstream substrates and the heat from the multiple downstream substrates are transferred together to one of the upstream circulation section and the downstream circulation section. Therefore, the cooling efficiency of the light source module can be further improved.

[0145] In the second and third aspects, the cooling plate may include a partition wall that extends in the second direction and divides the internal space of the cooling plate into the upstream flow portion and the downstream flow portion. With this configuration, as with the above, the distance in the first direction between the upstream circulation section and the downstream circulation section can be shortened compared to when the upstream circulation section and the downstream circulation section are each surrounded by different outer walls, and the cooling plate can be made smaller.

[0146] In the second and third aspects, the plurality of heat transfer sections may be provided in each of the upstream circulation section and the downstream circulation section. According to this configuration, similarly to the above, the pressure loss of the coolant can be reduced in each of the upstream circulation section and the downstream circulation section, and therefore the cooling efficiency of the cooling plate to which heat from the light source module is transferred via the heat receiving plate can be increased without using a large pump. Also, in each of the upstream circulation section and the downstream circulation section, the heat generated in the light source module can be easily transferred to the multiple heat transfer sections, and the multiple heat transfer sections transfer heat to the coolant, thereby increasing the cooling efficiency of the light source module.

[0147] A projector according to a fourth aspect of the present disclosure includes a light source device according to any one of the first to third aspects, an image forming device that modulates light emitted from the light source device to form image light, and a projection optical device that projects the image light formed by the image forming device. This configuration can achieve the same effects as the light source devices according to the first to third aspects described above, and can reduce the size of the projector. Furthermore, since the cooling efficiency of the light source module is improved, it is easier to increase the amount of light emitted from the light source module, and therefore the brightness of the projected image can be increased.

[0148] A cooling plate according to a fifth aspect of the present disclosure is a cooling plate through which a coolant can flow, and comprises: an inlet portion provided in a portion in a first direction along an edge portion and through which the coolant flows; an outlet portion provided in a portion opposite the first direction relative to the portion through which the coolant flows; an upstream circulation portion through which the coolant flowing in from the inlet portion flows in a second direction perpendicular to the first direction; a downstream circulation portion through which the coolant that has flowed through the upstream circulation portion flows in a direction opposite to the second direction; and a plurality of heat transfer portions provided in at least one of the upstream circulation portion and the downstream circulation portion and arranged side by side in the second direction, wherein the plurality of heat transfer portions extend along the second direction and have a plurality of fins arranged along the first direction and a plurality of flow paths provided between the plurality of fins through which the coolant can flow, and each of the plurality of heat transfer portions is spaced apart from each other in the second direction.

[0149] With this configuration, the coolant flow path in each heat transfer section can be made shorter than when a single heat transfer section is provided corresponding to the lengths of the multiple heat transfer sections in the second direction, thereby reducing the pressure loss of the coolant. This allows the coolant to flow more easily through the multiple heat transfer sections, thereby increasing the flow rate of the coolant in the cooling plate without using a large pump and improving the cooling efficiency of the cooling plate. [Explanation of symbols]

[0150] 1...projector, 34...image forming device, 36...projection optical device, 4...light source device, 6...light source section, 61, 61A, 64, 64A, 65, 66...first light source section, 611, 611A, 641, 661...first light source module (light source module), 612, 642, 662...base, 612A, 662A...upstream base, 612B, 662B...downstream base, 613...light emitting element, 614, 644, 644A, 654, 664...first heat receiving plate (heat receiving plate), 614A, 664A...upstream heat receiving plate, 614B, 664B...downstream heat receiving plate, 615, 655...first cooling plate , 615A, 655A...end, 616...first plate element, 616A...first surface, 617...heat transfer section, 6171...fin, 6172...flow path, 617A...upstream heat transfer section, 617B...downstream heat transfer section, 618...second plate element, 618B...end, 6181...inlet section, 6182...outlet section, 6183...recess, 6184...partition wall, 6185...upstream circulation section, 6186...downstream circulation section, 6187...connection section, 62...second light source section, 621...second light source module (light source module), 624...second heat receiving plate, 625...second cooling plate, GP1, GP2...gap.

Claims

1. a light source module having a plurality of bases on which light emitting elements are arranged; a plurality of heat receiving plates connected to the light source module; a cooling plate connected to each of the plurality of heat receiving plates and through which a coolant flows, The cooling plate is an inlet portion provided in a portion in a first direction along the end portion, into which the cooling liquid flows; an outflow portion through which the coolant flows out, the outflow portion being provided in a portion opposite to the first direction with respect to the portion; an upstream flow section in which the coolant flowing in from the inlet section flows in a second direction perpendicular to the first direction; a downstream flow section through which the cooling liquid having flowed through the upstream flow section flows in a direction opposite to the second direction; a plurality of heat transfer sections provided in the upstream circulation section and the downstream circulation section, respectively, and arranged side by side in the second direction; The plurality of heat transfer portions include: an upstream heat transfer section provided in the upstream flow section; a downstream heat transfer portion provided in the downstream circulation portion and spaced apart from the upstream heat transfer portion in the first direction, Each of the upstream heat transfer section and the downstream heat transfer section is a plurality of fins extending along the second direction and arranged along the first direction; a plurality of flow paths provided between the plurality of fins and through which the cooling liquid can flow; The plurality of heat receiving plates are an upstream heat receiving plate disposed corresponding to the upstream flow portion; a downstream heat receiving plate disposed in correspondence with the downstream flow portion and spaced apart from the upstream heat receiving plate in the first direction, The light source device, characterized in that the plurality of heat transfer portions are spaced apart from one another at positions corresponding to the spaces between the plurality of heat receiving plates in the second direction.

2. a light source module having a plurality of bases on which light emitting elements are arranged; a plurality of heat receiving plates connected to the light source module; a cooling plate connected to each of the plurality of heat receiving plates and through which a coolant flows, The cooling plate is an inlet portion provided in a portion in a first direction along the end portion, into which the cooling liquid flows; an outflow portion through which the coolant flows out, the outflow portion being provided in a portion opposite to the first direction with respect to the portion; an upstream flow section in which the coolant flowing in from the inlet section flows in a second direction perpendicular to the first direction; a downstream flow section through which the cooling liquid having flowed through the upstream flow section flows in a direction opposite to the second direction; a plurality of heat transfer sections provided in the upstream circulation section and the downstream circulation section, respectively, and arranged side by side in the second direction; The plurality of heat transfer portions include: a plurality of fins extending along the second direction and arranged along the first direction; a plurality of flow paths provided between the plurality of fins and through which the cooling liquid can flow; the plurality of heat receiving plates are arranged along the second direction corresponding to the upstream flow section and the downstream flow section, respectively; the plurality of heat transfer portions are spaced apart from one another at positions corresponding to the spaces between the plurality of heat receiving plates in the second direction, the plurality of substrates are arranged side by side in the second direction, A light source device characterized in that each of the plurality of heat receiving plates is arranged in a line in the second direction and is connected to an end portion in the second direction of a corresponding one of the plurality of bases.

3. 3. The light source device according to claim 2, Each of the plurality of heat receiving plates is an upstream heat receiving portion disposed corresponding to the upstream flow portion; a downstream heat receiving portion disposed corresponding to the downstream flow portion.

4. 4. The light source device according to claim 2, The light source device is characterized in that the plurality of heat transfer sections are spaced apart from one another at positions where they do not overlap with the light emitting element.

5. a light source module having a plurality of bases on which light emitting elements are arranged; a plurality of heat receiving plates connected to the light source module; a cooling plate connected to each of the plurality of heat receiving plates and through which a coolant flows, The cooling plate is an inlet portion provided in a portion in a first direction along the end portion, into which the cooling liquid flows; an outflow portion through which the coolant flows out, the outflow portion being provided in a portion opposite to the first direction with respect to the portion; an upstream flow section in which the coolant flowing in from the inlet section flows in a second direction perpendicular to the first direction; a downstream flow section through which the cooling liquid having flowed through the upstream flow section flows in a direction opposite to the second direction; a plurality of heat transfer sections provided in the upstream circulation section and the downstream circulation section, respectively, along the second direction, The plurality of heat transfer portions include: an upstream heat transfer section provided in the upstream flow section; a downstream heat transfer portion provided in the downstream circulation portion and spaced apart from the upstream heat transfer portion in the first direction, Each of the upstream heat transfer section and the downstream heat transfer section is a plurality of fins extending along the second direction and arranged along the first direction; a plurality of flow paths provided between the plurality of fins and through which the cooling liquid can flow; the plurality of substrates are arranged side by side in the second direction, The plurality of heat receiving plates are an upstream heat receiving plate provided in accordance with the upstream flow section; a downstream heat receiving plate provided in accordance with the downstream flow section and spaced apart from the upstream heat receiving plate in the first direction, The plurality of substrates are a plurality of upstream bases arranged side by side in the second direction and connected to the upstream heat receiving plate; a plurality of downstream bases arranged side by side in the second direction and connected to the downstream heat receiving plate; The light source device, characterized in that the plurality of heat transfer portions are spaced apart from each other at positions corresponding to between two of the plurality of light emitting elements aligned in the second direction.

6. a light source module having a plurality of bases on which light emitting elements are arranged; a plurality of heat receiving plates connected to the light source module; a cooling plate connected to each of the plurality of heat receiving plates and through which a coolant flows, The cooling plate is an inlet portion provided in a portion in a first direction along the end portion, into which the cooling liquid flows; an outflow portion through which the coolant flows out, the outflow portion being provided in a portion opposite to the first direction with respect to the portion; an upstream flow section in which the coolant flowing in from the inlet section flows in a second direction perpendicular to the first direction; a downstream flow section through which the cooling liquid having flowed through the upstream flow section flows in a direction opposite to the second direction; a plurality of heat transfer sections provided in the upstream circulation section and the downstream circulation section, respectively, along the second direction, The plurality of heat transfer portions include: a plurality of fins extending along the second direction and arranged along the first direction; a plurality of flow paths provided between the plurality of fins and through which the cooling liquid can flow; the plurality of substrates are arranged side by side in the second direction, Each of the plurality of heat receiving plates is an upstream heat receiving section provided in accordance with the upstream flow section; a downstream heat receiving section provided in accordance with the downstream flow section, The plurality of substrates are a plurality of upstream bases arranged side by side in the second direction and connected to the upstream heat receiving portion; a plurality of downstream bases arranged side by side in the second direction and connected to the downstream heat receiving portion, the plurality of heat transfer units are spaced apart from one another at positions corresponding to between two of the plurality of light emitting elements arranged in the second direction, A light source device characterized in that each of the plurality of heat receiving plates is arranged in a line in the second direction and is connected to an end portion in the second direction of a corresponding one of the plurality of bases.

7. 7. The light source device according to claim 1, The light source device, wherein the cooling plate includes a partition wall extending in the second direction and partitioning an internal space of the cooling plate into the upstream flow section and the downstream flow section.

8. The light source device according to any one of claims 1 to 7; an image forming device that modulates the light emitted from the light source device to form image light; a projection optical device that projects the image light formed by the image forming device.

Images