Light source device, and projector

Abstract

To provide a light source device including a Peltier element, capable of preventing condensation from occurring.SOLUTION: A light source device 10 includes: a light-emitting element 12; a heat sink 14 that has a first surface 14a abutting on the light-emitting element 12 and a second surface 14b on the opposite side of the first surface 14a; a heat absorbing surface 16a that abuts on the second surface 14b of the heat sink 14; a Peltier element 16 that includes a heat radiating surface 16b on the opposite side of the heat absorbing surface 16a; a heat sink 18 that abuts on the heat dissipation surface 16b of the Peltier element 16; a frame 20 that opens in the stacking direction of the light-emitting element 12, the heat sink 14, the Peltier element 16, and the heat sink 18, and supports them in the stacked state; and sealing members 22 and 24 that fills inside of the frame 20 so as to cover the heat sink 14 and the Peltier element 16.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] For example, Patent Document 1 discloses a light-emitting unit (light source device) that can prevent moisture from entering the connection between the power receiving terminal and the connection terminal of a light-emitting element. In this light source device, the light-emitting element is attached to the bottom surface of a recess formed in a heat sink and is covered with a sealing member made of an insulating resin material that fills the recess. This prevents moisture from entering the power receiving terminal of the light-emitting element from the outside. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-310138 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, some light source devices are equipped with Peltier elements to efficiently cool light-emitting elements. However, condensation may occur in the light source device due to cooling by the Peltier elements. Specifically, condensation may occur in parts of the light source device that come into contact with outside air and become colder than the dew point temperature of the outside air due to cooling by the Peltier elements. This condensation (water) may cause corrosion or short circuits.

[0005] Therefore, an object of the present disclosure is to suppress the occurrence of condensation in a light source device including a thermoelectric element such as a Peltier element. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, according to one aspect of the present disclosure, A light-emitting element; a heat sink having a first surface on which the light emitting element is provided and a second surface opposite to the first surface; a thermoelectric element including a heat absorption surface thermally connected to the second surface of the heat sink and a heat radiation surface opposite to the heat absorption surface, the thermoelectric element generating a temperature difference by passing an electric current therethrough; a frame that opens in the stacking direction of the light emitting element, the heat sink, and the thermoelectric element and supports them in a stacked state; a sealing member filled in the frame so as to cover the heat sink and the thermoelectric element, the frame includes a first recess having a first opening that opens on one side in the stacking direction, and a second recess having a second opening that opens on the other side in the stacking direction, The sealing member filled in the first recess constitutes a first sealing portion, and the sealing member filled in the second recess constitutes a second sealing portion.

[0007] Furthermore, according to another aspect of the present disclosure, A projector is provided that includes the light source device. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to suppress the occurrence of condensation in a light source device including a thermoelectric element such as a Peltier element. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a top perspective view of a light source device according to a first embodiment of the present disclosure; [Figure 2] 1 is a bottom perspective view of a light source device according to a first embodiment; [Figure 3] FIG. 1 is an exploded perspective view of a light source device according to a first embodiment. [Figure 4] Cross-sectional view of the light source device taken along line 4-4 in Figure 1. [Figure 5] 10 is a cross-sectional view of a light source device according to a second embodiment of the present disclosure. [Figure 6] 10 is a cross-sectional view of a light source device according to a third embodiment of the present disclosure. [Figure 7] FIG. 10 is an exploded perspective view of a light source device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] A light source device according to one embodiment of the present disclosure comprises a light-emitting element, a heat sink having a first surface on which the light-emitting element is provided and a second surface opposite the first surface, a thermoelectric element having a heat absorption surface thermally connected to the second surface of the heat sink and a heat dissipation surface opposite the heat absorption surface, and through which an electric current is passed to create a temperature difference, a frame body that opens in the stacking direction of the light-emitting element, the heat sink, and the thermoelectric element and supports them in a stacked state, and a sealing member filled in the frame body to cover the heat sink and the thermoelectric element, wherein the frame body includes a first recess having a first opening that opens on one side of the stacking direction and a second recess having a second opening that opens on the other side of the stacking direction, and the sealing member filled in the first recess constitutes a first sealing portion, and the sealing member filled in the second recess constitutes a second sealing portion.

[0011] According to this aspect, it is possible to suppress the occurrence of condensation in a light source device equipped with a thermoelectric element such as a Peltier element.

[0012] For example, the second opening may be larger than the first opening, and the second recess may have a bottom surface that connects with the second opening and the first recess.

[0013] The heat sink may be supported by the frame with a portion of the first surface seated on a bottom surface of the second recess.

[0014] The thermoelectric element may include a heat sink thermally connected to the heat dissipation surface.

[0015] For example, the thickness of the second sealing portion from the second surface of the heat sink may be smaller than the thickness of the thermoelectric element.

[0016] For example, at least one of the first sealing portion and the second sealing portion may contain expanded particles having a thermal conductivity lower than that of the sealing member.

[0017] For example, the light source device may have a heat insulating member provided on at least one of the first surface and the second surface of the heat sink, in which case the heat insulating member is covered by the first sealing portion or the second sealing portion.

[0018] For example, the frame may have a mounting plane that is parallel to the bottom surface of the second recess and that comes into surface contact with an external member.

[0019] For example, the light emitting element may be a laser light source that emits laser light.

[0020] For example, the thermoelectric element may be a Peltier element.

[0021] A projector according to another aspect of the present disclosure includes the light source device.

[0022] According to this aspect, it is possible to suppress the occurrence of condensation in the light source device of the projector.

[0023] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters or redundant descriptions of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art.

[0024] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0025] (Embodiment 1) The light source device according to the first embodiment will be described below with reference to FIGS.

[0026] FIG. 1 is a top perspective view of a light source device according to the first embodiment. FIG. 2 is a bottom perspective view of the light source device according to the first embodiment. FIG. 3 is an exploded perspective view of the light source device according to the first embodiment. And FIG. 4 is a cross-sectional view of the light source device taken along line 4-4 in FIG. 1. Note that the XYZ coordinate system shown in the drawings is intended to facilitate understanding of the embodiments of the present disclosure and does not limit the embodiments. The Z-axis direction is the thickness direction of the light source device, and the X-axis and Y-axis directions are planar directions.

[0027] As shown in Figures 1 to 4, the light source device 10 according to the first embodiment is a device used as a light source for a projector, for example, and includes a light emitting element 12, a heat sink 14, a Peltier element 16, a heat sink 18, and a frame body 20.

[0028] The light emitting element 12 is a device that emits light, for example, a laser light source that emits directional laser light, and emits the laser light in the thickness direction of the light source device 10 (Z-axis direction).

[0029] The heat sink 14 is a plate-shaped member made of a material with high thermal conductivity, for example, a metal material such as aluminum, and has a first surface 14a and a second surface 14b opposite to the first surface 14a. The first surface 14a of the heat sink 14 is provided with a heat absorption portion 14c that abuts against the light emitting element 12 and absorbs heat from the light emitting element 12.

[0030] The Peltier element 16 includes a heat absorption surface 16a that abuts against the second surface 14b of the heat sink 14 and absorbs heat from the heat sink 14, a heat dissipation surface 16b on the opposite side of the heat absorption surface 16a, and a power supply line 16c for receiving a supply of power. The Peltier element 16 receives a supply of power from the power supply line 16c, and a current flows through it, causing a temperature difference between the heat absorption surface 16a and the heat dissipation surface 16b. The Peltier element 16 is an example of a thermoelectric element that has the function of creating a temperature difference by passing a current through it.

[0031] The heat sink 18 is a member made of a material with high thermal conductivity, for example, a metal material such as aluminum, and has a first surface 18a that abuts against the heat dissipation surface 16b of the Peltier element 16, and a second surface 18b opposite to the first surface 18a. A plurality of heat dissipation fins 18c are provided on the second surface 18b.

[0032] The frame body 20 is a frame-shaped member that opens in the stacking direction (Z-axis direction) of the light emitting element 12, the heat sink 14, the Peltier element 16, and the heat sink 18, and is a housing for the light source device 10. As shown in Fig. 4, the frame body 20 supports the light emitting element 12, the heat sink 14, the Peltier element 16, and the heat sink 18 in a stacked state.

[0033] In the first embodiment, the frame 20 is made of a material, such as a resin material, having a thermal conductivity lower than that of the heat sink 14, for reasons that will be described later. As shown in Fig. 4, the frame 20 has a first recess 20b with a first opening 20a that opens on one side in the stacking direction (Z-axis direction) of the light emitting element 12, the heat sink 14, the Peltier element 16, and the heat sink 18, and a second recess 20d with a second opening 20c that opens on the other side in the stacking direction. The first recess 20b is connected to a bottom surface 20e of the second recess 20d, thereby communicating with the second recess 20d.

[0034] 4, part of first surface 14a of heat sink 14 is seated on bottom surface 20e of second recess 20d, and is thereby supported by frame 20. In order to suppress heat transfer between heat sink 14 and frame 20 via bottom surface 20e, frame 20 is made of a material with lower thermal conductivity than that of heat sink 14.

[0035] Furthermore, in the case of the present embodiment 1, the light emitting element 12 is fixed to the first surface 14a of the heat sink 14 with screws (not shown) while being in contact with the heat absorption portion 14c of the heat sink 14. As a result, the light emitting element 12 is supported by the frame 20 via the heat sink 14 with a portion of the light emitting element 12 housed in the first recess 20b of the frame 20.

[0036] Furthermore, in the case of the first embodiment, the heat sink 14, the Peltier element 16, and the heat sink 18 are fixed to the frame 20 with screws (not shown) with the Peltier element 16 sandwiched between the heat sink 14 and the heat sink 18. This maintains contact between the second surface 14b of the heat sink 14 and the heat absorption surface 16a of the Peltier element 16, and also maintains contact between the heat dissipation surface 16b of the Peltier element 16 and the first surface 18a of the heat sink 18. The heat sink 14 and the Peltier element 16 are housed in a second recess 20d of the frame 20.

[0037] Additionally, in the first embodiment, the frame 20 includes a mounting plane 20f that allows the light source device 10 to be in surface contact with an external component and attached to the external component. That is, the frame 20 functions as a bracket for the light source device 10. For example, the light source device 10 is attached to a projector housing via the mounting plane 20f of the frame 20 and functions as part of the projector. The mounting plane 20f is parallel to the bottom surface 20e of the second recess 20d and, as a result, parallel to the first surface 14a of the heat sink 14. The light emitting element 12 is attached to the heat sink 14 so that the traveling direction of the emitted light is substantially perpendicular to the first surface 14a of the heat sink 14. Therefore, by using the mounting plane 20f as a positioning reference, the light source device 10 can be attached to an external component, such as a projector housing, with the traveling direction of the emitted light appropriately adjusted. As a result, variations in the brightness of the light projected from the light emitting element 12 onto a screen can be reduced.

[0038] With this structure, heat from the light-emitting element 12 is transferred to the heat sink 14 via the first surface 14a of the heat sink 14. The heat from the heat sink 14 is absorbed by the Peltier element 16 via the heat-absorbing surface 16a of the Peltier element 16, which is in contact with the second surface 14b of the heat sink 14. The heat generated by the Peltier element 16 due to this heat absorption is transferred to the heat sink 18 via the first surface 18a of the heat sink 18, which is in contact with the heat-dissipating surface 16b of the Peltier element 16. The heat from the heat sink 18 is then dissipated to the outside via the multiple heat-dissipating fins 18c. For example, the heat-dissipating fins 18c are cooled by cooling water circulating inside the projector or a fan installed in the projector housing. This heat transfer allows the light-emitting element 12 to be cooled by the Peltier element 16.

[0039] 4, in order to suppress condensation due to cooling of the Peltier element 16, a sealing member is filled in the first recess 20b and the second recess 20d of the frame body 20, thereby forming a first sealing portion 22 and a second sealing portion 24, respectively. Specifically, condensation may occur on the heat sink 14 and the heat absorption surface 16a of the Peltier element 16 due to cooling of the Peltier element 16. In order to suppress the occurrence of such condensation, the sealing member is filled in the first and second recesses 20b, 20d of the frame body 20 so as to cover the heat sink 14 and the Peltier element 16.

[0040] Specifically, the sealing member 26 filled in the first and second sealing portions 22, 24 is made of a highly fluid and hardenable insulating material, such as a curable resin. The sealing member 26 is also made of a material with low thermal conductivity. For example, epoxy resin, silicone resin, urethane resin, etc. are used as the sealing member 26.

[0041] The sealing member 26 forming the first sealing portion 22 is filled in a fluid state into the first recess 20b of the frame 20. The sealing member 26 of the first sealing portion 22 is filled into the first recess 20b so as to cover the heat sink 14, except for the heat absorption portion 14c on the first surface 14a of the heat sink 14 that abuts against the light emitting element 12. That is, the sealing member 26 is filled into the first recess 20b with the heat sink 14 attached to the frame 20 and the light emitting element 12 attached to the heat sink 14. After filling, the sealing member 26 is cured. In the first embodiment, a portion of the light emitting element 12 is embedded in the first sealing portion 22.

[0042] The sealing member 26 that forms the second sealing portion 24 is filled in a fluid state into the second recess 20d of the frame 20. The sealing member 26 of the second sealing portion 24 is filled into the second recess 20d so as to cover the heat sink 14 and the Peltier element 16, except for the portion of the heat dissipation surface 16b of the Peltier element 16 that abuts against the heat sink 18. That is, the sealing member 26 is filled into the second recess 20d with the heat sink 14 attached to the frame 20 and the Peltier element 16 sandwiched between the heat sink 14 and the heat sink 18. Then, after filling, the sealing member 26 is hardened.

[0043] 4, in the first embodiment, the heat sink 18 is not embedded in the second sealing portion 24 to enable the heat sink 18 to be detachable from the light source device 10. For this reason, the thickness t1 of the second sealing portion 24 from the second surface 14b of the heat sink 14 is made smaller than the thickness t2 of the Peltier element 16 that abuts against the second surface 14b of the heat sink 14. This allows the heat sink 18 to be detached non-destructively. As a result, for example, if a failure occurs in the light emitting element 12 or the Peltier element 16, the heat sink 18 can be removed from the failed light source device 10 and reused in a new light source device 10.

[0044] Being covered by such first and second sealing portions 22, 24 prevents heat sink 14 and Peltier element 16 from coming into contact with the outside air, thereby insulating them from the outside air. As a result, condensation is prevented from forming on heat sink 14 and Peltier element 16. For example, even if heat sink 14 is cooled to a temperature lower than the dew point temperature of the air outside light source device 10 (outside air), condensation does not form on heat sink 14 because it is covered by first and second sealing portions 22, 24.

[0045] The first and second sealing portions 22, 24 that cover the heat sink 14 and the Peltier element 16 are maintained at a temperature between the outside air temperature and the temperatures of the heat sink 14 and the Peltier element 16. To ensure that this temperature is higher than the dew point temperature of the outside air, that is, to prevent condensation from forming on the outer surfaces of the first and second sealing portions 22, 24, the sealing member 26 that forms the first and second sealing portions 22, 24 is made of a material with low thermal conductivity.

[0046] Furthermore, since the frame 20 is also made of a material with a thermal conductivity lower than that of the heat sink 14, the occurrence of condensation is suppressed.

[0047] According to the first embodiment described above, in the light source device 10 including the Peltier element 16, This can prevent condensation from occurring.

[0048] (Embodiment 2) The second embodiment is an improved version of the first embodiment. The second embodiment will be described with this in mind. The same reference numerals are used to denote the components of the second embodiment.

[0049] FIG. 5 is a cross-sectional view of a light source device according to the second embodiment of the present disclosure.

[0050] In the light source device 110 according to the second embodiment, the first and second sealing portions 122, 124 contain expanded beads 126 together with the sealing member 26. The expanded beads 126 have a lower thermal conductivity than that of the sealing member 26.

[0051] By including such expanded particles 126, the heat sink 14 and Peltier element 16 covered by the first and second sealing portions 122, 124 are more insulated from the outside air than if they did not include the expanded particles 126. Furthermore, the temperature of the outer surfaces of the first and second sealing portions 122, 124 becomes higher than if they did not include the expanded particles 126, and as a result, condensation is less likely to form on the outer surfaces.

[0052] The expanded particles 126 are contained in both the first and second sealing portions 122, 124, but may be contained in only one of them. That is, the expanded particles 126 are contained in at least one of the first sealing portion 122 and the second sealing portion 124. For example, the expanded particles 126 may be contained in the sealing portion of the first surface 14a or the second surface 14b of the heat sink 14 that is more likely to cause condensation.

[0053] According to the second embodiment described above, in the same way as in the first embodiment, it is possible to suppress the occurrence of condensation in the light source device 110 including the Peltier element 16.

[0054] (Embodiment 3) The present embodiment 3 is an improved version of the above-mentioned embodiment 1. Therefore, the description of the present embodiment 3 will be centered on the differences. Note that the same reference numerals are used to designate the components of the present embodiment 3 that are substantially the same as those of the embodiment 1.

[0055] Fig. 6 is a cross-sectional view of a light source device according to embodiment 3 of the present disclosure, and Fig. 7 is an exploded perspective view of the light source device according to embodiment 3.

[0056] As shown in Figures 6 and 7, in the light source device 210 of this embodiment 3, first and second heat insulating members 228, 230 are attached to the portion of the heat sink 14 that is not in contact with the light emitting element 12 and the Peltier element 16.

[0057] The first and second insulating members 228, 230 are made of, for example, a rubber material and have a closed-cell structure. The first insulating member 228 is attached to the first surface 14a of the heat sink 14, and the second insulating member 230 is attached to the second surface 14b of the heat sink 14.

[0058] The first heat insulating member 228 is covered by the sealing member 26 that forms the first sealing portion 222. Similarly, the second heat insulating member 230 is covered by the sealing member 26 that forms the second sealing portion 224.

[0059] The heat sink 14 and Peltier element 16 covered by the first and second sealing portions 222, 224 are further insulated from the outside air by the first and second heat insulating members 228, 230, compared to a case where the first and second heat insulating members 228, 230 are not present (for example, the light source device 10 of the first embodiment). Furthermore, the temperature of the outer surfaces of the first and second sealing portions 222, 224 becomes higher than a case where the first and second heat insulating members 228, 230 are not present, and as a result, condensation is less likely to occur on the outer surfaces.

[0060] Note that only one of the first heat insulating member 228 and the second heat insulating member 230 may be attached to the heat sink 14. That is, at least one of the first heat insulating member 228 and the second heat insulating member 230 is attached to the heat sink 14. For example, the heat insulating member may be attached to the sealing portion side of the first surface 14a or the second surface 14b of the heat sink 14 that is more likely to cause condensation.

[0061] Furthermore, at least one of the first and second sealing portions 222, 224 of the light source device 210 may contain the foamed particles 126 described in the second embodiment.

[0062] According to the third embodiment as described above, in the same way as in the first embodiment, it is possible to suppress the occurrence of condensation in the light source device 210 including the Peltier element 16.

[0063] Although the present disclosure has been described above by giving multiple embodiments 1 to 3, the present disclosure is not limited to these embodiments.

[0064] For example, the Peltier element may be controlled based on the temperature detection result of a temperature sensor attached to the heat sink. For example, the Peltier element may be controlled so that the temperature detection result of the temperature sensor, i.e., the temperature of the heat sink, is kept constant. In this case, the temperature sensor may be covered by a first sealing portion or a second sealing portion so that it is not affected by the outside air temperature.

[0065] Furthermore, when a temperature sensor is used, the operation of the Peltier element and / or the light-emitting element may be stopped when the temperature sensor detects a temperature at which condensation may occur on the outer surface of the first sealing portion or the second sealing portion.

[0066] Furthermore, in the case of the above-described first embodiment, as shown in Fig. 4, the first sealing portion 22 and the second sealing portion 24 are separated by the heat sink 14. However, the embodiment of the present disclosure is not limited to this. The first sealing portion and the second sealing portion may be connected.

[0067] As described above, the above-described embodiments have been described as examples of the technology of the present disclosure. For this purpose, drawings and detailed descriptions are provided. Therefore, the components described in the drawings and detailed descriptions may include not only components essential for solving the problem, but also components that are not essential for solving the problem in order to exemplify the above-described technology. Therefore, the fact that these non-essential components are described in the drawings or detailed descriptions should not be interpreted as immediately indicating that these non-essential components are essential.

[0068] Furthermore, since the above-described embodiments are intended to illustrate the technology of the present disclosure, various modifications, substitutions, additions, omissions, etc. may be made within the scope of the claims or their equivalents. [Industrial Applicability]

[0069] The present disclosure is applicable to a light source device including a Peltier element. [Explanation of symbols]

[0070] 10, 110, 210 light source device 12 Light-emitting element 14 Heat sink 14a First Surface 14b Second Surface 14c Heat absorption part 16 Peltier element 16a Endothermic surface 16b Heat dissipation surface 16c power supply line 18 Heatsink 20 Frame 20a First opening 20b First recess 20c Second opening 20d Second recess 20e bottom 20f Mounting plane 22, 122, 222 First sealing portion 24, 124, 224 Second sealing part 26 Sealing member 126 Foam particles 228 First heat insulating member 230 Second insulating member t1, t2 thickness

Claims

1. A light-emitting element; a heat sink having a first surface on which the light emitting element is provided and a second surface opposite to the first surface; a thermoelectric element including a heat absorption surface thermally connected to the second surface of the heat sink and a heat radiation surface opposite to the heat absorption surface, the thermoelectric element generating a temperature difference by passing an electric current therethrough; a frame that opens in the stacking direction of the light emitting element, the heat sink, and the thermoelectric element and supports them in a stacked state; a sealing member filled in the frame so as to cover the heat sink and the thermoelectric element, the frame includes a first recess having a first opening that opens on one side in the stacking direction, and a second recess having a second opening that opens on the other side in the stacking direction, The sealing member filled in the first recess constitutes a first sealing portion, and the sealing member filled in the second recess constitutes a second sealing portion.

2. the second opening is larger than the first opening; The light source device according to claim 1 , wherein the second recess has a second opening and a bottom surface that connects with the first recess.

3. The light source device according to claim 1 , wherein the heat sink is supported by the frame in a state where a portion of the first surface is seated on a bottom surface of the second recess.

4. The light source device according to claim 1 , further comprising a heat sink thermally connected to the heat dissipation surface of the thermoelectric element.

5. The light source device according to claim 1 , wherein a thickness of the second sealing portion from the second surface of the heat sink is smaller than a thickness of the thermoelectric element.

6. The light source device according to claim 5 , wherein at least one of the first sealing portion and the second sealing portion contains foam particles having a thermal conductivity lower than that of the sealing member.

7. a heat insulating member provided on at least one of the first surface and the second surface of the heat sink; The light source device according to claim 5 , wherein the heat insulating member is covered by the first sealing portion or the second sealing portion.

8. The light source device according to claim 5 , wherein the frame body includes a mounting plane that is parallel to a bottom surface of the second recess and that comes into surface contact with an external member.

9. The light source device according to claim 1 , wherein the light emitting element is a laser light source that emits laser light.

10. The light source device according to claim 1 , wherein the thermoelectric element is a Peltier element.

11. A projector comprising the light source device according to any one of claims 1 to 10.

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