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

[0006] , , , ,

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

Background Art

[0002] y<e000009>For example, Patent Document 1 discloses a light emitting unit (light source device) that can prevent moisture from entering the connection portion between the power receiving terminal and the connection terminal of a light emitting element. In this light source device, the light emitting element is mounted on the bottom surface of a recess formed in a heat sink, and is covered with a sealing member made of an insulating resin material filled in 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

Summary of the Invention

Problems to be Solved by the Invention

[0004] [[ID=)34]] By the way, in order to cool a light emitting element with high efficiency, a light source device may include a Peltier element. However, condensation may occur in the light source device due to the cooling of the Peltier element. Specifically, condensation may occur in a portion of the light source device that is in contact with the outside air and has become colder than the dew point temperature of the outside air due to the cooling of the Peltier element. Corrosion or short circuit may occur due to the condensation (water). x

[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 Problems

[0006] In order to solve the above problems, according to one aspect of the present disclosure, a light emitting element, and A heat sink comprising a first surface on which the light-emitting element is provided, and a second surface opposite to the first surface, A thermoelectric element comprising a heat-absorbing surface thermally connected to the second surface of the heat sink, and a heat-dissipating surface opposite to the heat-absorbing surface, which creates a temperature difference when an electric current is passed through it, A frame that has an opening in the stacking direction of the light-emitting element, the heat sink, and the thermoelectric element, and supports them in a stacked state, The heat sink and the thermoelectric element are enclosed within the frame and filled with a sealing member, The frame includes a first recess having a first opening that opens in one direction of the stacking direction, and a second recess having a second opening that opens in the other direction of the stacking direction. A light source device is provided, wherein 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 different aspects of this disclosure, A projector equipped with the aforementioned light source device is provided. [Effects of the Invention]

[0008] According to this disclosure, the occurrence of condensation can be suppressed in a light source device equipped with a thermoelectric element such as a Peltier element. [Brief explanation of the drawing]

[0009] [Figure 1] An upward perspective view of the light source device according to Embodiment 1 of this disclosure. [Figure 2] Downward perspective view of the light source device according to Embodiment 1 [Figure 3] Exploded perspective view of the light source device according to Embodiment 1 [Figure 4] Cross-sectional view of the light source device along line 4-4 in Figure 1. [Figure 5] Cross-sectional view of the light source device according to Embodiment 2 of this disclosure [Figure 6] Cross-sectional view of the light source device according to Embodiment 3 of this disclosure [Figure 7] Exploded perspective view of the light source device according to Embodiment 3

Mode for Carrying Out the Invention

[0010] A light source device according to an aspect of the present disclosure includes a light-emitting element, a heat dissipation plate having a first surface on which the light-emitting element is provided and a second surface opposite to the first surface, a heat absorption surface thermally connected to the second surface of the heat dissipation plate, a heat dissipation surface opposite to the heat absorption surface, a thermoelectric element that passes an electric current to create a temperature difference, a frame body that opens in the stacking direction of the light-emitting element, the heat dissipation plate, and the thermoelectric element and supports them in a stacked state, and a sealing member filled in the frame body so as to cover the heat dissipation plate and the thermoelectric element. The frame body 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.

[0011] According to such an aspect, in a light source device including a thermoelectric element such as a Peltier element, the occurrence of condensation can be suppressed.

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

[0013] The heat dissipation plate may be supported by the frame body in a state where a part of the first surface is seated on the bottom surface of the second recess.

[0014] The heat dissipation surface of the thermoelectric element may have a heat sink thermally connected thereto.

[0015] For example, the thickness of the second sealing portion from the second surface of the heat dissipation plate 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 foamed 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 radiating plate. In this case, the heat insulating member is covered by the first sealing portion or the second sealing portion.

[0018] For example, the frame body may have an attachment plane that is parallel to the bottom surface of the second recess and is in 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 different aspects of the present disclosure includes the light source device.

[0022] According to such an aspect, in the light source device of the projector, the occurrence of dew condensation can be suppressed.

[0023] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, a more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art.

[0024] Note that the accompanying drawings and the following description are provided for 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) Hereinafter, a light source device according to Embodiment 1 will be described with reference to FIGS. 1 to 4.

[0026] Figure 1 is an upper perspective view of the light source device according to this embodiment 1. Figure 2 is a lower perspective view of the light source device according to this embodiment 1. Furthermore, Figure 3 is an exploded perspective view of the light source device according to this embodiment 1. And Figure 4 is a cross-sectional view of the light source device along line 4-4 in Figure 1. Note that the XYZ coordinate system shown in the figures is for the purpose of facilitating the understanding of the embodiments of this 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 this embodiment 1 is a device used, for example, as a light source for a projector, and comprises a light-emitting element 12, a heat sink 14, a Peltier element 16, a heat sink 18, and a frame 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 laser light in the thickness direction (Z-axis direction) of the light source device 10.

[0029] The heat sink 14 is a plate-shaped member made from a material with high thermal conductivity, such as a metal material such as aluminum, and comprises 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-absorbing portion 14c that contacts the light-emitting element 12 and absorbs heat from the light-emitting element 12.

[0030] The Peltier element 16 comprises a heat-absorbing surface 16a that contacts the second surface 14b of the heat sink 14 and absorbs heat from the heat sink 14, a heat-dissipating surface 16b opposite to the heat-absorbing surface 16a, and a power supply line 16c for receiving power. The Peltier element 16 receives power from the power supply line 16c, and when an electric current flows, it creates a temperature difference between the heat-absorbing surface 16a and the heat-dissipating surface 16b. The Peltier element 16 is an example of a thermoelectric element that has the function of creating a temperature difference by passing an electric current.

[0031] The heat sink 18 is a component made of a material with high thermal conductivity, such as a metallic material such as aluminum, and comprises a first surface 18a that is in contact with the heat dissipation surface 16b of the Peltier element 16, and a second surface 18b opposite to the first surface 18a. The second surface 18b is provided with a plurality of heat dissipation fins 18c.

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

[0033] In this embodiment 1, the frame 20 is made of a material having a lower thermal conductivity than the heat sink 14, for reasons to be explained later, such as a resin material. Furthermore, as shown in Figure 4, the frame 20 includes 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, heat sink 14, Peltier element 16, and 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 the bottom surface 20e of the second recess 20d, thereby communicating with the second recess 20d.

[0034] Furthermore, in this embodiment 1, as shown in Figure 4, the heat sink 14 is supported by the frame 20 by a portion of its first surface 14a sitting on the bottom surface 20e of the second recess 20d. In order to suppress heat transfer between the heat sink 14 and the frame 20 via this bottom surface 20e, the frame 20 is made of a material having a thermal conductivity lower than that of the heat sink 14.

[0035] Furthermore, in this embodiment 1, the light-emitting element 12 is fixed to the first surface 14a of the heat sink 14 by screws (not shown) while in contact with the heat-absorbing 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 it housed in the first recess 20b of the frame 20.

[0036] Furthermore, in this embodiment 1, the heat sink 14, the Peltier element 16, and the heat sink 18 are fixed to the frame 20 by 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-absorbing surface 16a of the Peltier element 16, as well as contact between the heat-dissipating surface 16b of the Peltier element 16 and the first surface 18a of the heat sink 18. In addition, the heat sink 14 and the Peltier element 16 are housed in the second recess 20d of the frame 20.

[0037] In addition, in this embodiment 1, the frame 20 has a mounting plane 20f that makes surface contact with an external member and to which the light source device 10 is attached. 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 the housing of a projector via the mounting plane 20f of the frame 20 and functions as part of the projector. This mounting plane 20f is parallel to the bottom surface 20e of the second recess 20d and, as a result, is also parallel to the first surface 14a of the heat sink 14. The light-emitting element 12 is attached to the heat sink 14 such that the direction of propagation 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 member, such as the housing of a projector, while appropriately adjusting the direction of propagation of the emitted light. As a result, variations in the brightness of the light projected from the light-emitting element 12 onto the screen can be suppressed.

[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 that 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 that is in contact with the heat-dissipating surface 16b of the heat sink 18. The heat from the heat sink 18 is then dissipated to the outside via a plurality of heat dissipation fins 18c. For example, the heat dissipation fins 18c are cooled by cooling water circulating inside the projector or by a fan provided on the projector housing. Through this heat transfer, the light-emitting element 12 is cooled by the Peltier element 16.

[0039] To suppress condensation caused by the cooling of the Peltier element 16, as shown in Figure 4, a sealing member is filled into the first recess 20b and the second recess 20d of the frame 20, forming the first sealing portion 22 and the second sealing portion 24, respectively. Specifically, condensation may occur on the heat sink 14 and the heat-absorbing surface 16a of the Peltier element 16 due to the cooling of the Peltier element 16. To suppress the occurrence of this condensation, the sealing member is filled into the first and second recesses 20b and 20d of the frame 20 so as to cover the heat sink 14 and the Peltier element 16.

[0040] Specifically, the sealing member 26 that fills the first and second sealing portions 22 and 24 is made from a highly fluid, curable insulating material, such as a curable resin. Furthermore, the sealing member 26 is made from a material with low thermal conductivity. For example, epoxy resin, silicone resin, or urethane resin can be used as the sealing member 26.

[0041] The sealing member 26 forming the first sealing portion 22 is filled into the first recess 20b of the frame 20 in a fluid state. 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-absorbing portion 14c that contacts the light-emitting element 12 on the first surface 14a of the heat sink 14. 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 hardened. In this embodiment 1, a part 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 into the second recess 20d of the frame 20 in a fluid state. 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 Peltier element 16 that contacts the heat sink 18, specifically the heat sink 14 and the Peltier element 16. That is, 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, the sealing member 26 is filled into the second recess 20d. After filling, the sealing member 26 is hardened.

[0043] As shown in Figure 4, in this embodiment 1, the heat sink 18 is not embedded in the second sealing portion 24 in order to make the heat sink 18 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 smaller than the thickness t2 of the Peltier element 16 that contacts the second surface 14b of the heat sink 14. This allows the heat sink 18 to be attached and detached non-destructively. As a result, for example, if a light-emitting element 12 or Peltier element 16 fails, the heat sink 18 can be removed from the failed light source device 10 and reused in a new light source device 10.

[0044] By being covered by these first and second sealing portions 22 and 24, the heat sink 14 and the Peltier element 16 are prevented from coming into contact with the outside air and are insulated from the outside air. As a result, condensation on the heat sink 14 and the Peltier element 16 is suppressed. For example, even if the heat sink 14 is cooled to a temperature lower than the dew point temperature of the outside air (outside air) of the light source device 10, condensation will not occur on the heat sink 14 because it is covered by the first and second sealing portions 22 and 24.

[0045] The first and second sealing portions 22 and 24 covering the heat sink 14 and the Peltier element 16 are maintained at a temperature between the temperature of the heat sink 14 and the Peltier element 16 and the ambient temperature. The sealing members 26 forming the first and second sealing portions 22 and 24 are made from a material with low thermal conductivity so that this temperature is higher than the dew point temperature of the ambient air, that is, so that condensation does not occur on the outer surfaces of the first and second sealing portions 22 and 24.

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

[0047] According to this embodiment 1 described above, in the light source device 10 equipped with a Peltier element 16 This helps to suppress the occurrence of condensation.

[0048] (Embodiment 2) This second embodiment is an improved version of the first embodiment described above. Therefore, the differences are as follows: With that in mind, let me explain Embodiment 2. Note that the components are substantially the same as those of Embodiment 1. The components of this embodiment 2 are given the same reference numerals.

[0049] Figure 5 is a cross-sectional view of a light source device according to Embodiment 2 of this disclosure.

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

[0051] By including such foamed particles 126, the heat sink 14 and Peltier element 16 covered by the first and second sealing portions 122 and 124 are further insulated from the outside air compared to when the foamed particles 126 are not included. In addition, the temperature of the outer surface of the first and second sealing portions 122 and 124 becomes higher compared to when the foamed particles 126 are not included, and as a result, condensation is less likely to occur on their outer surface.

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

[0053] According to this embodiment 2 described above, similar to embodiment 1 described above, the occurrence of condensation can be suppressed in the light source device 110 equipped with the Peltier element 16.

[0054] (Embodiment 3) This third embodiment is an improved version of the first embodiment described above. Therefore, this third embodiment will be described focusing on the differences. Components of this third embodiment that are substantially the same as those of the first embodiment are denoted by the same reference numerals.

[0055] Figure 6 is a cross-sectional view of the light source device according to Embodiment 3 of this disclosure. Figure 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 according to this embodiment 3, the first and second heat insulating members 228 and 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 thermal insulation members 228 and 230 are made from, for example, a rubber material and have a closed-cell foam structure. The first thermal insulation member 228 is attached to the first surface 14a of the heat sink 14, and the second thermal insulation member 230 is attached to the second surface 14b of the heat sink 14.

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

[0059] With these first and second insulating members 228 and 230, the heat sink 14 and Peltier element 16 covered by the first and second sealing portions 222 and 224 are further insulated from the outside air compared to when the first and second insulating members 228 and 230 are not present (for example, the light source device 10 of Embodiment 1). In addition, the temperature of the outer surface of the first and second sealing portions 222 and 224 becomes higher than when the first and second insulating members 228 and 230 are not present, and as a result, condensation is less likely to occur on the outer surface.

[0060] Furthermore, either the first thermal insulation member 228 or the second thermal insulation member 230 may be attached to the heat sink 14. That is, at least one of the first thermal insulation member 228 and the second thermal insulation member 230 is attached to the heat sink 14. For example, the thermal insulation member may be attached to the sealing portion side of the heat sink 14 where condensation is more likely to occur, between the first surface 14a and the second surface 14b.

[0061] Furthermore, at least one of the first and second sealing portions 222 and 224 of the light source device 210 may contain the foamed particles 126 described in Embodiment 2.

[0062] According to this embodiment 3 described above, similar to embodiment 1 described above, the occurrence of condensation can be suppressed in the light source device 210 equipped with the Peltier element 16.

[0063] Although the present disclosure has been described above with reference to several embodiments 1 to 3, the embodiments of the present disclosure are not limited to these.

[0064] For example, the Peltier element may be controlled based on the temperature detection result of a temperature sensor attached to a 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, remains constant. In this case, the temperature sensor may be covered by a first or second sealing part so that it is not affected by the ambient temperature.

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

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

[0067] As described above, the embodiments described in this disclosure have been explained as examples of the technology. For this purpose, drawings and a detailed description are provided. Therefore, among the components described in the drawings and detailed description, there may be not only components that are essential for solving the problem, but also components that are not essential for solving the problem, in order to illustrate the technology described above. For this reason, the mere fact that these non-essential components are described in the drawings and detailed description should not be immediately assumed to be essential.

[0068] Furthermore, since the embodiments described above are for illustrative purposes of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the scope of the claims or equivalents thereof. [Industrial applicability]

[0069] This disclosure is applicable to light source devices equipped with Peltier elements. [Explanation of Symbols]

[0070] 10, 110, 210 light source device 12 Light-emitting elements 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 base 20f Mounting surface 22, 122, 222 First sealing section 24, 124, 224 Second sealing section 26 Sealing member 126 foaming particles 228 First insulating member 230 Second insulation component t1, t2 thickness

Claims

1. Light-emitting element and A heat sink comprising a first surface on which the light-emitting element is provided, and a second surface opposite to the first surface, A thermoelectric element comprising a heat-absorbing surface thermally connected to the second surface of the heat sink, and a heat-dissipating surface opposite to the heat-absorbing surface, which creates a temperature difference when an electric current is passed through it, A frame that has an opening in the stacking direction of the light-emitting element, the heat sink, and the thermoelectric element, and supports them in a stacked state, The heat sink and the thermoelectric element are enclosed within the frame and filled with a sealing member, The frame includes a first recess having a first opening that opens in one direction of the stacking direction, and a second recess having a second opening that opens in the other direction of the stacking direction. A light source device wherein 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 comprises a second opening and a bottom surface connected to the first recess.

3. The light source device according to claim 1 or 2, wherein the heat sink is supported by the frame with a portion of the first surface seated on the bottom surface of the second recess.

4. The light source device according to claims 1 to 3, 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 the thickness of the second sealing portion from the second surface of the heat sink is smaller than the 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 foamed particles having a thermal conductivity lower than that of the sealing member.

7. The heat sink has a heat insulating member provided on at least one of the first surface and the second surface, The light source device according to claim 5 or 6, wherein the heat insulating member is covered by the first sealing portion or the second sealing portion.

8. The light source device according to any one of claims 5 to 7, wherein the frame has a mounting surface that is parallel to the bottom surface of the second recess and makes surface contact with an external member.

9. The light source device according to any one of claims 1 to 8, wherein the light-emitting element is a laser light source that emits laser light.

10. The light source device according to any one of claims 1 to 9, wherein the thermoelectric element is a Peltier element.

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

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