Light source device and projector

Abstract

To provide a light source device which can be made compact, and a projection device equipped with the light source device.SOLUTION: The light-source device 30 includes a first light-emitting module 40U having a first light-emitting device, a second light-emitting module 40D having a second light-emitting device, and a thermoelectric conversion device 70 disposed closer to the first light-emitting module 40U between the first light-emitting module 40D and the second light-emitting module 40U.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] There is a known technology for reducing speckle noise by generating wavelength differences due to temperature differences between laser elements. For example, Patent Document 1 discloses a light source device that reduces speckle noise by superimposing multiple laser beams with different wavelengths in a certain color gamut. This light source device arranges multiple laser elements on support parts with different thermal conductivities, thereby varying the temperatures of the laser elements and generating wavelength differences, and superimposing the multiple laser beams with different wavelengths at a predetermined ratio to reduce speckle noise. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-70139 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the light source device of Patent Document 1, when reducing speckle noise in a light source device using multiple laser elements, when the multiple laser elements are viewed, for example, from above the laser elements, the individual laser elements are arranged in parallel in the direction of emission from each laser element to the optical system, which makes the laser element unit large.

[0005] In view of the above, an object of the present invention is to provide a light source device that can be made compact, and a projection device that includes this light source device. [Means for solving the problem]

[0006] The light source device of the present invention comprises a first light-emitting module having a first light-emitting element, a second light-emitting module having a second light-emitting element, and a thermoelectric exchange element arranged between the first light-emitting module and the second light-emitting module, closer to the first light-emitting module.

[0007] The projection device of the present invention comprises the above-mentioned light source device, a display element that generates image light using the light from the light source device, and a projection optical system that projects the image light emitted from the display element onto a projection target. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a light source device that can be made compact, and a projection device that includes this light source device. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a plan view schematically illustrating a configuration of a projection device including a light source device according to a first embodiment. [Figure 2] 2 is a view taken along the CC cross section of FIG. 1, and is a schematic right side view showing the emission mode of laser light in the light source device according to the first embodiment. FIG. [Figure 3] 10 is a schematic right side view showing the emission mode of laser light in the light source device according to the second embodiment. FIG. [Figure 4] 10 is a schematic right side view showing the emission mode of laser light in the light source device according to the third embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] A first embodiment of the present invention will be described below with reference to Figures 1 and 2. As shown in Figure 1, a projection device 10 according to this embodiment includes a housing 20, a light source device 30 provided inside the housing 20, an irradiation mirror 22, an image display element (display element) 24, a lens barrel (projection optical system) 26, and a control circuit board (control unit) 28 for controlling the electrical configuration of the projection device 10. As shown in Figures 1 and 2, the light source device 30 includes four light-emitting modules 40U, 40U, 40D, 40D that emit laser light, temperature sensors 48U, 48D, a microlens array (integrator optical system) 50, four reflecting members 60U, 60U, 60D, 60D, a condensing lens 62, a concave lens 64, a diffuser plate 66, a thermoelectric exchange element 70, a heat-receiving member 72, and two heat pipes (thermal conduction members) 74. Inside the housing 20, various components that are included in known projection devices, such as a heat sink and a cooling fan, are provided, although not shown.

[0011] The control circuit board 28 controls the image display element 24 and the light source device 30. The projection device 10 generates image light on the image display element 24 by irradiating the image display element 24 with ray bundles of laser light emitted from each of the light emitting modules 40U, 40U, 40D, 40D via the condenser lens 62, the concave lens 64, the microlens array 50, and the irradiation mirror 22. The projection device 10 then emits the image light generated on the image display element 24 to the outside of the housing 20 via the lens barrel 26 in the direction of arrow L, and projects and displays the image on a projection target such as a screen.

[0012] 1 and 2, the four light emitting modules 40U, 40U, 40D, 40D are so-called multi-chip modules (MCMs). The light emitting modules 40U, 40U are arranged in the approximate center of the light source substrate 42U, and the light emitting modules 40D, 40D are arranged in the approximate center of the light source substrate 42D, respectively, in the front-to-rear direction (X direction). The light emitting modules 40U, 40U may be different light emitting units or the same light emitting unit, and the light emitting modules 40D, 40D may be different light emitting units or the same light emitting unit. However, one of the light emitting modules 40U, 40U and one of the light emitting modules 40D, 40D are made of the same material and have the same thermal conductivity, and the other of the light emitting modules 40D, 40D is made of the same material and have the same thermal conductivity. Therefore, when the same control signal for controlling light emission is supplied from control circuit board 28, which serves as the control unit, to light-emitting modules 40U, 40U and light-emitting modules 40D, 40D, respectively, the wavelength range of light from light-emitting modules 40U, 40U and the wavelength range of light from light-emitting modules 40D, 40D are equal to each other in an environment where light-emitting modules 40U, 40U, 40D, 40D are at the same temperature. On the other hand, when the temperatures of light-emitting modules 40U, 40U and light-emitting modules 40D, 40D differ, the wavelength range of light from light-emitting modules 40U, 40U and the wavelength range of light from light-emitting modules 40D, 40D become shifted from each other. Mixing of these shifted lights reduces speckle noise. The light source substrate 42U has a main surface 42UM and a mounting surface 42US located on the opposite side of the main surface 42UM, and the light source substrate 42D has a main surface 42DM and a mounting surface 42DS located on the opposite side of the main surface 42DM. The light source substrates 42U and 42D are arranged such that the mounting surfaces 42US and 42DS face each other, with the main surface 42UM facing upward and the main surface 42DM facing downward. Light-emitting modules 40U, 40U are provided in the front-rear direction on the main surface 42UM of the light source substrate 42U, and light-emitting modules 40U, 40U are provided in the front-rear direction on the main surface 42UM of the light source substrate 42U. Light-emitting units 44U, 44U are provided within the light-emitting modules 40U, 40U, respectively.Similarly, light-emitting modules 40D, 40D are provided with light-emitting units 44D, 44D, respectively. The pair of light-emitting units 44U, 44U and the pair of light-emitting units 44D, 44D each include three types of light-emitting elements (at least one red light-emitting element 46R, at least one blue light-emitting element 46B, and at least one green light-emitting element 46G). For simplicity of explanation, an example will be described in which one light-emitting unit 44U includes one red light-emitting element 46R, one blue light-emitting element 46B, and one green light-emitting element 46G, and one light-emitting unit 44D includes one red light-emitting element 46R, one blue light-emitting element 46B, and one green light-emitting element 46G. The blue light-emitting element 46B is a semiconductor light-emitting element that emits laser light in a blue wavelength band (e.g., 430 to 490 nm). The red light-emitting element 46R is a semiconductor light-emitting element that emits laser light in a red wavelength band (e.g., 640 to 770 nm). The green light emitting element 46G is a semiconductor light emitting element that emits laser light in a green wavelength band (for example, 490 to 550 nm). In this way, the light source device 30 is arranged in a position where the light emitting modules 40U, 40U (or the light source substrate 42U) overlap with the light emitting modules 40D, 40D (or the light source substrate 42D) in the vertical direction (Z direction) perpendicular to the XY plane, so that the light source device 30 can be housed compactly within the housing 20 of the projection device 10.

[0013] Each laser beam emitted from the light-emitting units 44U, 44U, 44D, 44D is incident on the microlens array 50 via the reflecting members 60U, 60D, the condenser lens 62, the concave lens 64, and the diffuser plate 66. Each laser beam emitted from the microlens array 50 is incident on the image display element 24 via the irradiation mirror 22. The diffuser plate 66 mixes the light from the light-emitting units 44U, 44U and the light from the light-emitting units 44D, 44D, which have wavelength ranges that are shifted from each other due to a temperature difference, and allows the mixed light to reach the microlens array 50. The microlens array 50 includes a substantially rectangular array substrate 51. As shown in FIG. 2, the microlens array 50 according to this embodiment has a main axis MA (i.e., the optical axis of the microlens array 50) aligned in the normal direction to the array substrate 51. In the following, the direction along the main axis MA is the front-to-rear direction (X direction) of the light source device 30, the microlens array 50 side of each light-emitting module 40U, 40D is the front side, and the opposite side is the rear side, and the left-to-right direction (Y direction) from the rear side to the front side is the left-to-right direction of the light source device 30. The front-to-rear direction and the left-to-right direction are orthogonal to each other. Furthermore, the direction orthogonal to the front-to-rear direction and the left-to-right direction will be described as the up-down direction (the Z direction, which is the overlapping direction, and in which the upper side in FIG. 2 is the up direction).

[0014] The thermoelectric exchange element 70 is a substantially rectangular, thick plate-like member, such as a Peltier element. The Peltier element can absorb or radiate heat on one side and radiate or absorb heat on the other side by changing the direction of current flow using the control unit 28. Here, the light source substrate 42U is arranged so that the installation surface 42US is in contact with the heat-absorbing surface (the surface facing upward) of the thermoelectric exchange element 70. The heat-receiving member 72 is a substantially rectangular, thick plate-like member with excellent thermal conductivity. The sizes of the thermoelectric exchange element 70 and the heat-receiving member 72 in the planar directions (front-to-back and left-to-right directions) are substantially equal. The thermoelectric exchange element 70 is arranged so that its heat-radiating surface (the surface facing downward) is in contact with the surface of the heat-receiving member 72 facing upward. The light source substrate 42D is arranged so that the installation surface 42DS is in contact with the surface of the heat-receiving member 72 facing downward. In this way, the light source substrate 42U on which the light emitters 44U, 44U are provided, the thermoelectric exchange element 70, the heat receiving member 72, and the light source substrate 42D on which the light emitters 44D, 44D are provided are arranged in this order from top to bottom, and the heat of the light source substrate 42U and the heat of the light source substrate 42D are ultimately transferred to the heat receiving member 72. For this reason, the heat of the light source substrate 42U is almost never transferred to the light source substrate 42D, causing the light source substrate 42D to become hot, and the heat of the light source substrate 42D is almost never transferred to the light source substrate 42U, causing the light source substrate 42U to become hot. Therefore, when the thermoelectric exchange element 70 absorbs heat from the light-emitting units 44U, 44U via the light source substrate 42U, a temperature difference occurs between the light-emitting units 44U, 44U and the light-emitting units 44D, 44D due to the heat absorption. When the same control signal is supplied to the light-emitting units 44U, 44U and the light-emitting units 44D, 44D due to this temperature difference, a difference occurs between the wavelength range of the light emitted from the light-emitting units 44U, 44U and the wavelength range of the light emitted from the light-emitting units 44D, 44D. The light of this different wavelength range mixes and reaches the microlens array 50, where it is projected from the projection device 10. Since the projected light is free of speckle noise, a display with excellent visibility can be achieved. Thus, the thermoelectric exchange element 70 is disposed between the light-emitting modules 40U, 40U and the light-emitting modules 40D, 40D, closer to the light-emitting modules 40U, 40U, which should be kept at a relatively lower temperature.The temperature sensors 48U, 48D are provided on the surfaces of the light source substrates 42U, 42D corresponding to the light-emitting modules 40U, 40U, 40D, 40D, respectively, and detect the temperatures due to the heat generated by the light-emitting modules 40U, 40U and the temperatures due to the heat generated by the light-emitting modules 40D, 40D via the light source substrates 42U, 42D. The detected temperature information of the light-emitting modules 40U, 40U and the temperature information of the light-emitting modules 40D, 40D are transmitted as detection signals to the control unit 28. The control unit 28 controls the thermoelectric exchange element 70 and the light-emitting units 44U, 44U, 44D, 44D to maintain a temperature difference sufficient to eliminate speckle noise.

[0015] 2, the reflecting members 60U, 60U are provided above the light-emitting modules 40U, 40U, and the reflecting members 60D, 60D are provided below the light-emitting modules 40D, 40D. The reflecting members 60U, 60U are arranged at an angle so that their reflecting surfaces 60Ua, 60Ua face both the light-emitting module 40U side and the microlens array 50 side. Similarly, the reflecting members 60D, 60D are arranged at an angle so that their reflecting surfaces 60Da, 60Da face both the light-emitting module 40D side and the microlens array 50 side. The reflecting surfaces 60Ua, 60Ua of the reflecting members 60U, 60U reflect the laser light emitted from the light-emitting elements 46R, 46B, 46G of the light-emitting modules 40U, 40U, respectively, toward the microlens array 50 side. Similarly, the reflecting surfaces 60Da, 60Da of the reflecting members 60D, 60D reflect the laser light emitted from the light emitting elements 46R, 46B, 46G of the light emitting modules 40D, 40D toward the microlens array 50, respectively.

[0016] Here, specific arrangements of the light-emitting modules 40U, 40U, 40D, 40D and the reflecting members 60U, 60U, 60D, 60D will be described. As shown in FIG. 2, the light-emitting modules 40U, 40U and the light-emitting modules 40D, 40D are arranged approximately symmetrically in the vertical direction with respect to the thermoelectric exchange element 70 and the heat-receiving member 72. Specifically, the light-emitting modules 40U, 40D sandwich the thermoelectric exchange element 70 and the heat-receiving member 72 in the vertical direction. Here, "sandwiching" as used herein means that there is no space between the light-emitting modules 40U, 40D on both sides and they are sandwiched in a state of contact with the sandwiched object. The thermoelectric exchange element 70 is layered on top of and in contact with the heat-receiving member 72. The light source substrate 42U of the light-emitting modules 40U, 40U is arranged on top of the thermoelectric exchange element 70 so that the light-emitting units 44U, 44U protruding from the light source substrate 42U are positioned on top of the thermoelectric exchange element 70. The light source substrate 42D of the light-emitting modules 40D is disposed below the heat-receiving member 72 so that the light-emitting sections 44D protruding from the light source substrate 42D are positioned below. In this manner, the vertical direction in which the heat-receiving member 72 and the thermoelectric exchange element 70 overlap coincides with the thickness direction of the light source device 30.

[0017] The reflecting members 60U, 60U are respectively positioned such that their reflecting surfaces 60Ua, 60Ua are aligned along the left-right direction and form angles of approximately 45° with respect to the up-down direction and the front-to-back direction. Similarly, the reflecting members 60D, 60D are respectively positioned such that their reflecting surfaces 60Da are aligned along the left-right direction and form angles of approximately 45° with respect to the up-down direction and the front-to-back direction. Therefore, the laser light emitted from the light-emitting modules 40U, 40U and reflected by the reflecting members 60U, 60U and the laser light emitted from the light-emitting modules 40D, 40D and reflected by the reflecting members 60D, 60D enter a single condenser lens 62 with their optical axes parallel to the main axis MA. The distance between the light-emitting units 44U, 44D arranged on the rear side and their corresponding reflecting members 60U, 60D is longer than the distance between the light-emitting units 44U, 44D arranged on the front side and their corresponding reflecting members 60U, 60D. As a result, the optical path L1 of the laser light emitted from the light-emitting units 44U, 44D located at the rear and incident on the focusing lens 62 is positioned outward in the vertical direction from the optical path L2 of the laser light emitted from the light-emitting units 44U, 44D located at the front and incident on the focusing lens 62.

[0018] The two heat pipes 74 are arranged so that portions of them extend laterally and contact the heat-receiving member 72. Specifically, one end of each heat pipe 74 passes through the heat-receiving member 72 and is arranged so as to vertically overlap the light-emitting modules 40U, 40U, 40D, 40D and be closer to the light-emitting modules 40U, 40U in the vertical direction. Therefore, the heat pipe 74 is structured to transmit heat from the light source substrate 42U on which the light-emitting units 44U, 44U are mounted, which is absorbed by the thermoelectric exchange element 70, more preferentially than heat from the light source substrate 42D on which the light-emitting units 44D, 44D are mounted, thereby easily creating a temperature difference between the light-emitting units 44U, 44U and the light-emitting units 44D, 44D. The other end of each heat pipe 74 is connected to a heat sink. A refrigerant (not shown) flows through each heat pipe 74. At one end of each heat pipe 74, the refrigerant is vaporized by heat from the light-emitting modules 40U, 40U, 40D, and 40D via the thermoelectric exchange element 70 and the heat-receiving member 72, and then moves to the other end (heat sink side) where the temperature is lower. The vaporized refrigerant that has moved to the other end is cooled by the heat sink and liquefied, and then moves back to the one end. The heat-receiving member 72 and each heat pipe 74 are made of aluminum or copper, which have good thermal conductivity.

[0019] Next, referring to FIG. 2, the temperature control of the light-emitting modules 40U, 40U, 40D, and 40D by the control unit 28 will be described. When the light-emitting modules 40U, 40U, 40D, and 40D are supplied with power from a power supply unit (not shown) via the control unit 28 and operate, they generate heat due to energy conversion loss and the like. The heat generated from the light-emitting modules 40U, 40U is conducted to the heat-receiving member 72 via the thermoelectric exchange element 70. On the other hand, the heat generated from the light-emitting modules 40D, 40D is conducted directly to the heat-receiving member 72 substantially without passing through the thermoelectric exchange element 70. The heat conducted to the heat-receiving member 72 is dissipated to the outside of the housing 20 by a heat sink via each heat pipe 74.

[0020] In this heat dissipation process, the control unit 28 controls the thermoelectric exchange element 70 based on the temperatures detected by the temperature sensors 48U and 48D so that the temperatures of the light-emitting modules 40U, 40U, 40D, and 40D are within an operating temperature range and so that the temperature difference between the light-emitting modules 40U, 40U and the light-emitting modules 40D, 40D is within a predetermined range. The thermoelectric exchange element 70 absorbs heat from the light-emitting modules 40U, 40U on the side in contact with the light-emitting modules 40U, 40U and dissipates heat from the opposite side, in accordance with the control of the control unit 28. Meanwhile, the light-emitting modules 40D, 40D naturally dissipate heat without relying on the thermoelectric exchange element 70, which allows a temperature gradient to be created between the light-emitting modules 40U, 40U and the light-emitting modules 40D, 40D. The operating temperatures of the light-emitting modules 40U, 40U, 40D, and 40D controlled by the control unit 28 are, for example, within a range of 0 to 40°C. The temperature difference between light-emitting modules 40U, 40U and light-emitting modules 40D, 40D is, for example, within a range of 10°C to 20°C. In this case, the difference in the amount of deviation between the wavelength range of the laser light emitted from light-emitting modules 40U, 40U and the wavelength range of the laser light emitted from light-emitting modules 40D, 40D, which occurs due to the temperature difference, is about 4 nm, and speckle noise is reduced in the laser light obtained by combining these. At this time, control unit 28 controls the temperature difference between light-emitting modules 40U and 40D based on the wavelength difference of the green wavelength band light.

[0021] As described above, the light source device 30 according to this embodiment includes a heat-receiving member 72, a thermoelectric exchange element 70 arranged so as to overlap at least a portion of the heat-receiving member 72, and light-emitting units 44U, 44D in which a plurality of light-emitting elements 46R, 46B, 46G that emit laser light having different emission wavelengths are arranged in a row, and is provided with a plurality of light-emitting modules 40U, 40D that are respectively arranged so as to sandwich at least a portion of the heat-receiving member 72 and the thermoelectric exchange element 70, and a control unit 28 that controls the temperature difference between the plurality of light-emitting modules 40U, 40D.

[0022] The light source device 30 has the above-described configuration, in which the light-emitting modules 40U, 40D are stacked vertically perpendicular to the planar direction. This allows the light-emitting modules 40U, 40D, the thermoelectric exchange element 70, and the heat-receiving member 72 to be compactly unitized, compared to a conventional configuration in which multiple laser elements (multiple light-emitting modules) are arranged in parallel in the direction of emission from the laser elements to the optical system (planar direction). This allows for space saving in the light source device 30 in the direction of emission from the laser elements to the integrator optical system (the direction of the main axis MA), thereby enabling the light source device 30 to be miniaturized. Furthermore, since only one thermoelectric exchange element 70 is controlled, control is simpler than a configuration with multiple support parts with different thermal conductivities. This facilitates wavelength differentiation of laser light within a certain color gamut, enabling stable speckle noise reduction without being affected by the temperature conditions of the laser element arranged in the support part with lower thermal conductivity. In this manner, in this embodiment, it is possible to realize a light source device 30 that can stably reduce speckle noise while achieving miniaturization in the emission direction of the laser element.

[0023] Furthermore, in the light source device 30 of this embodiment, one ends of the heat pipes 74 are arranged to pass through the heat-receiving member 72 and overlap the light-emitting modules 40U and 40D in the vertical direction. With this configuration, heat generated in each of the light-emitting modules 40U, 40U, 40D, 40D is transferred to the heat pipes 74 via the heat-receiving member 72 via a short heat transfer path, and the temperature gradient in the heat-receiving member 72 is uniformed in the heat transfer direction. This facilitates temperature control by the thermoelectric exchange element 70, enabling stable reduction of speckle noise. Furthermore, one ends of the heat pipes 74 are arranged closer to the light-emitting modules 40U and 40U. With this configuration, heat absorbed from the light-emitting modules 40D and 40D by the thermoelectric exchange element 70 is more easily transferred than when the heat pipes 74 are arranged closer to the light-emitting modules 40D and 40D. This makes it easier to control the temperature difference between the light-emitting modules 40U, 40U and the light-emitting modules 40D, 40D. On the other hand, if it is not easy to control the temperature with the control unit 28 because the thermoelectric exchange elements 70 absorb heat sensitively, the heat pipes 74, 74 may be arranged closer to the light-emitting modules 40D, 40D to make temperature control easier. Note that although this reduces heat dissipation efficiency, the heat pipes 74, 74 may be arranged to vertically overlap only one of the light-emitting modules 40U, 40U and the light-emitting modules 40D, 40D in order to easily maintain an appropriate temperature gradient.

[0024] Furthermore, in the light source device 30 of this embodiment, the control unit 28 controls the temperature difference between the light-emitting modules 40U, 40U and the light-emitting modules 40D, 40D based on the wavelength difference of the green wavelength band light. Since the green wavelength band light has a greater effect on human vision than the red wavelength band light or the blue wavelength band light, this configuration can efficiently reduce speckle noise. Furthermore, in the light source device 30 of the present embodiment, the light source substrates 42U and 42D are provided with temperature sensors 48U and 48D, respectively. With this configuration, the temperatures of the light emitting modules 40U and 40U and the light emitting modules 40D and 40D can be detected via the light source substrates 42U and 42D, respectively. This allows the light emitting modules 40U, 40U, 40D and 40D, the thermoelectric exchange element 70, the heat receiving member 72 including the heat pipe 74, and the temperature sensors 48U and 48D to be compactly unitized, and can improve the accuracy of temperature control of the light emitting modules 40U and 40U and the light emitting modules 40D and 40D. Furthermore, in the light source device 30 of this embodiment, the vertical direction in which the thermoelectric exchange element 70 and the heat-receiving member 72 overlap coincides with the thickness direction of the light source device 30. By aligning the heat transfer direction of the thermoelectric exchange element 70 and the heat-receiving member 72 with the thickness direction of the light source device 30 and sandwiching the light-emitting modules 40U, 40U, 40D, 40D vertically, the layout of the light-emitting modules 40U, 40U, 40D, 40D does not need to be extended more than necessary in the front-to-back direction (X direction) and left-to-right direction (Y direction). Therefore, the light-emitting modules 40U, 40U have small temperature differences in the front-to-back direction and left-to-right direction, and the light-emitting modules 40D, 40D have small temperature differences in the front-to-back direction and left-to-right direction. This facilitates temperature control by the thermoelectric exchange element 70 and enables stable reduction of speckle noise. The thickness direction of the light source device 30 does not need to coincide with the main axis MA (front-to-back direction) of the microlens array 50. Specifically, the thermoelectric exchange element 70 and the heat-receiving member 72 may be arranged so as to overlap in the front-rear direction and be perpendicular to the main axis MA. Furthermore, the light source device 30 of this embodiment includes a microlens array 50 onto which laser beams emitted from the light-emitting units 44U, 44U, 44D, 44D are incident, and reflecting members 60U, 60U, 60D, 60D each including reflecting surfaces 60Ua, 60Ua, 60Da, 60Da that reflect the laser beams emitted from the light-emitting units 44U, 44U, 44D, 44D toward the microlens array 50. As a result, the laser beams emitted from the light-emitting units 44U, 44D in a direction perpendicular to the main axis MA of the microlens array 50 (up and down direction) are incident on the microlens array 50 along the main axis MA. Furthermore, in the light source device 30 of this embodiment, the laser beams emitted from the light-emitting modules 44U, 44U, 44D, and 44D are incident on the microlens array 50 via the diffuser plate 66. Since the laser beams are diffused by the diffuser plate 66, color unevenness in the projected light can be suppressed. Note that the position of the diffuser plate 66 does not have to be between the concave lens 64 and the microlens array 50, as long as it is on the optical path of the laser beams emitted from the light-emitting modules 40U, 40U, 40D, and 40D and reaching the microlens array 50.

[0025] A projection device 10 can be provided that includes the light source device 30 of this embodiment configured as described above, an image display element 24, and a projection optical system 26, in which a control unit 28 controls the light source device 30 and the image display element 24, and the laser light emitted from the microlens array 50 is incident on the image display element 24.

[0026] Next, light source devices 130, 230 according to second and third embodiments of the present invention will be described. The second embodiment described below differs from the first embodiment in that a concave lens 64 is not provided between the light-emitting modules 40D, 40D and the microlens array 50, and the third embodiment differs from the first embodiment in the size of the heat-receiving member 272 and the arrangement of the heat pipes 274U, 274D. The configurations and arrangements of the light-emitting modules, heat exchange elements, reflecting members, condensing lenses, diffusers, and microlens arrays are the same as those in the first embodiment, so they are denoted by the same reference numerals as in the first embodiment and will not be described again.

[0027] First, a light source device 130 according to the second embodiment will be described with reference to Fig. 3. As shown in Fig. 3, in the light source device 130 according to the second embodiment, the laser beams emitted from the light emitters 44U, 44U, 44D, 44D are incident on the microlens array 50 via the reflecting members 60U, 60U, 60D, 60D, the condenser lens 62, and the diffuser plate 66. As a result, the light source device 130 of the present embodiment does not include a concave lens, thereby reducing the number of components, and is more compact and simplified in the direction of emission from the light emitters 44U, 44U, 44D, 44D to the microlens array 50 than the first embodiment.

[0028] Next, a light source device 230 according to a third embodiment will be described with reference to FIG. 4. As shown in FIG. 4, in the light source device 230 according to the third embodiment, the heat-receiving member 272 is thinner (longitudinal) and slightly larger in planar directions (front-rear and left-right directions) than the heat-receiving member 72 of the first embodiment, with its edge portions positioned outside the thermoelectric exchange element 70 in planar directions. A heat pipe 274U is disposed at the front end of the upper side of the heat-receiving member 272, and a heat pipe 274D is disposed at the rear end of the lower side of the heat-receiving member 272. In other words, the heat pipes 274U and 274D are positioned so as to be point-symmetric with respect to the center of the heat-receiving member 272 when viewed from the right. As a result, the light source device 230 according to this embodiment is smaller in size in the vertical direction than the light source device 30 according to the first embodiment, and is smaller in size in the left-right direction than a conventional configuration in which multiple laser elements (multiple light-emitting modules) are arranged in parallel in the direction of emission from the laser elements to the optical system (planar direction). As a result, the light source device 230 is made smaller overall.

[0029] The above-described embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments may be embodied in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their modifications are within the scope and spirit of the invention, and are also encompassed by the claims and their equivalents. For example, while the above embodiments illustrate a configuration in which one red light-emitting element, one blue light-emitting element, and one green light-emitting element are provided in one light-emitting module, multiple red light-emitting elements, multiple blue light-emitting elements, or multiple green light-emitting elements may be provided in one light-emitting module depending on the light-emitting efficiency of each wavelength band light. Furthermore, while the above embodiments illustrate a configuration in which light-emitting elements are arranged in a single row in one light-emitting module, multiple light-emitting elements may be arranged in multiple rows in one light-emitting module. Furthermore, in the above-described embodiments, each of the light-emitting units 44U, 44U, 44D, 44D is provided with one blue light-emitting element 46B, one green light-emitting element 46G, and one red light-emitting element 46R. However, one of the light-emitting units 44U, 44U may be provided with one of the blue light-emitting element 46B, the green light-emitting element 46G, and the red light-emitting element 46R, and the other may be provided with the remaining two of the blue light-emitting element 46B, the green light-emitting element 46G, and the red light-emitting element 46R. Since the light-emitting units 44D, 44D are paired with the light-emitting units 44U, 44U, it is preferable that the light-emitting units 44D, 44D have the same combination as the light-emitting units 44U, 44U. Furthermore, while the above-described embodiments illustrate a configuration in which the heat-receiving member and the thermoelectric exchange element are sandwiched vertically between the light-emitting modules, they may also be sandwiched in any planar direction (front-to-back, left-to-right). Even in this case, the light-emitting modules are arranged closer to each other than in a configuration in which the light-emitting modules are arranged parallel to each other in the light emission direction, thereby enabling the light source device to be made more compact. Furthermore, in each of the above embodiments, a configuration in which two heat pipes are provided between the upper and lower light-emitting modules is exemplified, but a configuration in which one heat pipe is provided, or a configuration in which three or more heat pipes are provided, may also be used.In each embodiment, in order to counter speckle noise, the thermoelectric exchange element 70 is positioned closer to the light-emitting modules 40U, 40U, which should be kept at a relatively lower temperature than the light-emitting modules 40D, 40D. However, if the structure does not require countermeasures against speckle noise, the thermoelectric exchange element 70 does not necessarily need to be positioned closer to the light-emitting modules 40U, 40U. [Explanation of symbols]

[0030] 30, 130, 230...light source device, 28 control unit, 40U, 40D...light emitting module, 44U, 44D...light emitting unit, 46R, 46B, 46G...light emitting element, 70...thermoelectric exchange element, 72...heat receiving member

Claims

1. a first light emitting module having a first light emitting element; a second light-emitting module having a second light-emitting element; a thermoelectric exchange element disposed between the first light emitting module and the second light emitting module and closer to the first light emitting module; Light source device.

2. a heat-receiving member disposed between the second light-emitting module and the thermoelectric exchange element; a control unit that controls the thermoelectric exchange element; a heat conduction member provided so that a portion thereof is in contact with the heat receiving member, The light source device according to claim 1 .

3. the heat conduction member is provided between the first light emitting module and the second light emitting module so as to overlap with at least one of the first light emitting module and the second light emitting module; The light source device according to claim 2 .

4. the heat conduction member is provided so as to pass through positions closer to one side of the first light emitting module and the second light emitting module; The light source device according to claim 2 .

5. the thermoelectric exchange element is provided so as to overlap at least a portion of the heat-receiving member, the heat conducting member is provided so as to be in contact with a position of the heat receiving member that does not overlap with the thermoelectric exchange element; The light source device according to claim 2 .

6. the first light emitting module has a first main surface on which the first light emitting element of the first light emitting module is arranged, and a first installation surface that is a surface opposite to the first main surface; the second light-emitting module has a second main surface on which the second light-emitting element of the second light-emitting module is arranged, and a second installation surface that is a surface opposite to the second main surface, The thermoelectric exchange element is disposed between the first installation surface and the second installation surface. The light source device according to claim 1 .

7. a plurality of temperature sensors provided corresponding to each of the first light emitting module and the second light emitting module; The light source device according to claim 1 .

8. The thickness direction coincides with the overlapping direction of the heat-receiving member and the thermoelectric exchange element. The light source device according to claim 2 .

9. a reflecting member that reflects light emitted from the first light emitting module and the second light emitting module; an integrator optical system onto which the reflected light is incident; a diffusion plate provided on the optical path of the light reaching the integrator optical system, The light source device according to claim 1 .

10. The light source device according to any one of claims 1 to 9, a display element that generates image light using the light from the light source device; a projection optical system that projects the image light emitted from the display element onto a projection target, Projection device.

Images