Light source device and cooling method

Abstract

To efficiently dissipate heat from a plurality of light-emitting elements while using a common heat radiating part for the plurality of light-emitting elements.SOLUTION: A light source device comprises first and second light-emitting elements 611, 612, and a heat sink 8 that dissipates heat from the first and second light-emitting elements 611, 612. The heat sink 8 comprises: a first heat radiating part 821 disposed on a flow path PT of a fluid and configured to dissipate heat from the first and second light-emitting elements 611, 612 to the fluid; and a second heat radiating part 822 disposed on the flow path PT and configured to dissipate heat from the second light-emitting element 612 to the fluid. An allowable heat resistance of the heat sink regarding the first light-emitting element 611, which is determined from a difference between a maximum junction temperature and an ambient temperature as well as a heat generation amount, is greater than an allowable heat resistance of the heat sink regarding the second light-emitting element 612, which is determined from the difference between the maximum junction temperature and the ambient temperature as well as the heat generation amount.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] 2. Description of the Related Art Conventionally, a light source device including a plurality of light emitting elements has been known (see, for example, Patent Document 1). In the light source device described in Patent Document 1, in order to collectively cool a plurality of light-emitting elements, the plurality of light-emitting elements are thermally connected to the same heat dissipation section (cooling unit). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-158191 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a heat dissipation portion common to a plurality of light emitting elements is used as in the light source device described in Patent Document 1, the following problems may occur. For example, when the heat of a light-emitting element that generates a large amount of heat cannot be sufficiently dissipated, the temperature of the light-emitting element adjacent to the light-emitting element may rise in conjunction with the light-emitting element. As a result, the light-emitting efficiency of the adjacent light-emitting element may decrease because the adjacent light-emitting element cannot maintain an appropriate temperature. Therefore, there is a demand for a technique that can efficiently dissipate heat from a plurality of light-emitting elements while using a heat dissipation portion common to the plurality of light-emitting elements.

[0005] The present invention has been made in consideration of the above, and aims to provide a light source device and a cooling method that can efficiently dissipate heat from multiple light-emitting elements while using a heat dissipation section common to the multiple light-emitting elements. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the light source device of the present invention comprises a first light-emitting element, a second light-emitting element, and a heat sink that dissipates heat from the first light-emitting element and the second light-emitting element, wherein the heat sink comprises a first heat dissipation section that is arranged on a fluid flow path and dissipates heat from the first light-emitting element and the second light-emitting element to the fluid, and a second heat dissipation section that is arranged on the flow path and dissipates heat from the second light-emitting element to the fluid, and the allowable thermal resistance of the heat sink for the first light-emitting element calculated from the difference between the maximum junction temperature and the ambient temperature and the amount of heat generated is greater than the allowable thermal resistance of the heat sink for the second light-emitting element calculated from the difference between the maximum junction temperature and the ambient temperature and the amount of heat generated.

[0007] Furthermore, a cooling method according to the present invention is a cooling method for cooling a first light-emitting element and a second light-emitting element that are thermally connected to a heat sink having a first heat dissipation section and a second heat dissipation section, wherein heat from the first light-emitting element and the second light-emitting element is dissipated to the first heat dissipation section arranged on a fluid flow path, and heat from the second light-emitting element is dissipated to the second heat dissipation section arranged on the fluid flow path, and the allowable thermal resistance of the heat sink for the first light-emitting element calculated from the difference between the maximum junction temperature and the ambient temperature and the amount of heat generated is greater than the allowable thermal resistance of the heat sink for the second light-emitting element calculated from the difference between the maximum junction temperature and the ambient temperature and the amount of heat generated.

[0008] Furthermore, a light source device according to the present invention includes a first light-emitting element, a second light-emitting element, and a heat sink that dissipates heat from the first light-emitting element and the second light-emitting element, and the heat sink includes a first heat dissipation section that is arranged on a fluid flow path and dissipates heat from the first light-emitting element and the second light-emitting element to the fluid, a second heat dissipation section that is arranged on the flow path and dissipates heat from the second light-emitting element to the fluid, a first heat pipe that thermally connects the first light-emitting element and the first heat dissipation section, and a second heat pipe that thermally connects the second light-emitting element to the first heat dissipation section and the second heat dissipation section. Effect of the Invention

[0009] According to the light source device and cooling method of the present invention, it is possible to efficiently dissipate heat from a plurality of light-emitting elements while using a heat dissipation portion common to the plurality of light-emitting elements. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing a configuration of an endoscope system according to the first embodiment. [Diagram 2] FIG. 2 is a diagram showing the internal configuration of the light source device. [Diagram 3] FIG. 3 is a diagram illustrating the configuration of the cooling unit. [Figure 4] FIG. 4 is a diagram illustrating the configuration of the cooling unit. [Diagram 5] FIG. 5 is a diagram illustrating a modification 1-1 of the first embodiment. [Figure 6] FIG. 6 is a diagram illustrating a modification 1-1 of the first embodiment. [Figure 7] FIG. 7 is a diagram illustrating a configuration of a cooling unit according to the second embodiment. [Figure 8] FIG. 8 is a diagram illustrating a configuration of a cooling unit according to the second embodiment. [Figure 9] FIG. 9 is a diagram illustrating a configuration of a cooling unit according to the second embodiment. [Figure 10] FIG. 10 is a diagram illustrating a modification 2-1 of the second embodiment. [Figure 11] FIG. 11 is a diagram illustrating a modification 2-1 of the second embodiment. [Figure 12] FIG. 12 is a diagram illustrating a modified example 2-2 of the second embodiment. [Figure 13] FIG. 13 is a diagram illustrating a modified example 2-3 of the second embodiment. [Figure 14] FIG. 14 is a diagram illustrating a modification 3-1 of the first and second embodiments and the modifications 1-1 and 2-1 to 2-3. [Figure 15]FIG. 15 is a diagram illustrating a modification 3-1 of the first and second embodiments and the modifications 1-1 and 2-1 to 2-3. [Figure 16] FIG. 16 is a diagram illustrating a modification 3-2 of the first and second embodiments and the modifications 1-1 and 2-1 to 2-3. [Figure 17] FIG. 17 is a diagram illustrating a modification 3-3 of the first and second embodiments and the modifications 1-1 and 2-1 to 2-3. [Figure 18] FIG. 18 is a diagram illustrating a modification 3-3 of the first and second embodiments and the modifications 1-1 and 2-1 to 2-3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, a mode for carrying out the present invention (hereinafter, referred to as an embodiment) will be described with reference to the drawings. Note that the present invention is not limited to the embodiment described below. Furthermore, in the description of the drawings, the same parts are given the same reference numerals.

[0012] (Embodiment 1) [Configuration of the endoscope system] FIG. 1 is a diagram showing a configuration of an endoscope system 1 according to the first embodiment. The endoscope system 1 is used in the medical field and is a system for observing the inside of a subject (inside a living body). As shown in FIG.

[0013] In the first embodiment, the endoscope 2 is a so-called flexible endoscope. A part of the endoscope 2 is inserted into a living body, captures images of the inside of the living body, and outputs image signals generated by the capture. As shown in FIG. 1, the endoscope 2 includes an insertion section 21, an operation section 22, a universal cord 23, and a connector section 24.

[0014] The insertion section 21 is a section that is inserted into a living body and has at least a portion that is flexible. As shown in FIG. 1, a light guide 25, an illumination lens 26, and an imaging device 27 are provided in the insertion section 21.

[0015] The light guide 25 is routed from the insertion portion 21 through the operation portion 22 and the universal cord 23 to the connector portion 24. One end of the light guide 25 is located at the tip portion inside the insertion portion 21. When the endoscope 2 is connected to the processing device 4, the other end of the light guide 25 is located inside the processing device 4. The light guide 25 transmits light supplied from the light source device 6 in the processing device 4 from the other end to one end.

[0016] The illumination lens 26 faces one end of the light guide 25 inside the insertion portion 21. The illumination lens 26 irradiates the light transmitted by the light guide 25 into the living body.

[0017] The imaging device 27 is provided at the tip portion inside the insertion portion 21. The imaging device 27 has an imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) that receives a subject image from inside a living body and converts it into an electrical signal, and outputs an image signal generated by imaging.

[0018] The operation section 22 is connected to a base end portion of the insertion section 21. The operation section 22 receives various operations on the endoscope 2.

[0019] The universal cord 23 extends from the operating section 22 in a direction different from the extension direction of the insertion section 21, and is a cord on which signal lines and light guides 25 that electrically connect the imaging device 27 and the control device 5 in the processing device 4 are arranged.

[0020] The connector portion 24 is provided at the end of the universal cord 23 and is detachably connected to the processing device 4 .

[0021] The display device 3 is an LCD (Liquid Crystal Display) or an EL (Electro Luminescence) display, and displays an image after image processing by the processing device 4, etc.

[0022] 1, the processing device 4 includes a control device 5 and a light source device 6. In the present embodiment, the light source device 6 and the control device 5 are provided in one housing as the processing device 4, but the light source device 6 and the control device 5 may be provided in separate housings.

[0023] The light source device 6 supplies illumination light to the other end of the light guide 25 under the control of the control device 5 . The detailed configuration of the light source device 6 will be described later in the section "Configuration of the Light Source Device."

[0024] The control device 5 comprehensively controls the operation of the entire endoscope system 1. The control device 5 includes a control unit 51, a storage unit 52, and an input unit 53, as shown in FIG. The control unit 51 is configured to include a controller such as a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), or an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array), and controls the operation of the entire endoscope system 1.

[0025] The storage unit 52 stores various programs executed by the control unit 51, information necessary for the processing of the control unit 51, and the like.

[0026] The input unit 53 is configured using a keyboard, a mouse, a switch, a touch panel, etc., and accepts user operations by a user such as an operator. Then, the input unit 53 outputs to the control unit 51 an operation signal corresponding to the user operation.

[0027] [Configuration of the Light Source Device] Next, the configuration of the light source device 6 will be described. Fig. 2 is a diagram showing the internal configuration of the light source device 6. For ease of explanation, the cooling unit 7 is represented by a dashed line in Fig. 2. As shown in FIG. 2, the light source device 6 includes red, green, and blue light sources 611-613, first to fourth lenses 621-624, first to third dichroic mirrors 631-633, a cooling unit 7, and a housing 65 in which these components 611-613, 621-624, 631-633, and 7 are housed.

[0028] Red light source 611 is composed of a semiconductor light emitting element such as an LED (Light Emitting Diode) or an LD (Laser Diode), and emits red light (for example, light in a wavelength band of about 600 to 700 nm). This red light source 611 corresponds to the first light emitting element according to the present invention, and the first temperature is set as the maximum junction temperature.

[0029] Blue light source 613 is configured with a semiconductor light emitting element such as an LED or an LD, and emits blue light (for example, light in a wavelength band of about 430 to 490 nm). Blue light source 613 has a maximum junction temperature of a second temperature higher than the first temperature.

[0030] Green light source 612 is composed of a semiconductor light emitting element such as an LED or an LD, and emits green light (for example, light in a wavelength band of about 490 to 550 nm). This green light source 612 corresponds to a second light emitting element according to the present invention, and has a third temperature equal to or higher than the second temperature as a maximum junction temperature. That is, red light source 611 has a lower maximum junction temperature than green light source 612. Also, green light source 612 generates more heat than red light source 611.

[0031] The first to third dichroic mirrors 631 to 633 bend the light from the red, green, and blue light sources 611 to 613, respectively, and cause the light to travel along the same optical axis.

[0032] Specifically, first dichroic mirror 631 folds the red light emitted from red light source 611 and collected by first lens 621, and transmits light in wavelength bands other than the red light.

[0033] Second dichroic mirror 632 folds the green light emitted from green light source 612 and collected by second lens 622, and transmits light in wavelength bands other than the green light.

[0034] Third dichroic mirror 633 folds the blue light emitted from blue light source 613 and collected by third lens 623, and transmits light in wavelength bands other than the blue light.

[0035] Then, the fourth lens 624 collects the illumination light (white light) obtained by combining the red light, green light, and blue light that have passed through the first to third dichroic mirrors 631 to 633, and guides the light to the other end of the light guide 25.

[0036] In addition, in the housing 65, a side wall 651 (FIG. 2) on the side to which the other end of the light guide 25 is connected is a side wall on the front side where a doctor or the like who operates the endoscope 2 is present. And a side wall 652 (FIG. 2) opposed to the side wall 651 is a side wall on the rear side.

[0037] The cooling unit 7 dissipates heat generated in the red, green, and blue light sources 611-613. The detailed configuration of the cooling unit 7 will be described later in the section "Configuration of the cooling unit."

[0038] [Configuration of the cooling unit] Next, the configuration of the cooling unit 7 will be described. 3 and 4 are diagrams for explaining the configuration of the cooling unit 7. Specifically, FIG. 3 is a plan view showing the overall configuration of the cooling unit 7. FIG. 4 is a perspective view showing the configuration of the heat sink 8. In FIG. 3, the Z axis indicates an axis parallel to the vertical direction (the +Z axis direction is the upward direction). The X axis and the Y axis are two axes that are perpendicular to each other and perpendicular to the Z axis (the +X axis direction is the direction from the rear side wall 652 to the front side wall 651).

[0039] As shown in FIGS. 3 and 4, the cooling unit 7 includes a duct 71, a cooling fan 72, and a heat sink 8.

[0040] The duct 71 is disposed below (on the -Z axis direction side) the red, green, and blue light sources 611-613, the first to fourth lenses 621-624, and the first to third dichroic mirrors 631-633. One end of the duct 71 communicates with an intake hole (not shown) formed in a side wall 651 on the front side (on the +X axis side), and the other end communicates with an exhaust hole (not shown) formed in a side wall 652 on the rear side (on the -X axis side). The duct 71 forms a flow path PT (FIG. 3) that distributes air (fluid) from the intake hole toward the exhaust hole. As shown in FIG. 3, the red, green, and blue light sources 611-613 are disposed at a position corresponding to the upstream side (on the +X axis side) of the flow path PT, with the red light source 611 being disposed therein. A blue light source 613 is disposed at a position corresponding to the downstream side (−X axis side) of the flow path PT, and a green light source 612 is disposed between the red light source 611 and the blue light source 613.

[0041] The cooling fan 72 is disposed opposite the exhaust hole, and forcibly circulates air along the flow path PT in the duct 71 from the intake hole toward the exhaust hole.

[0042] The heat sink 8, as shown in FIGS. 3 and 4, includes first to third heat spreaders 811-813, first and second heat dissipation portions 821, 822, and first to third heat pipes 831-833.

[0043] As shown in FIGS. 3 and 4, first heat spreader 811 has a flat plate shape that is thermally connected to the back surface of red light source 611, and is a heat receiving section that receives heat generated in red light source 611.

[0044] As shown in FIGS. 3 and 4, second heat spreader 812 has a flat plate shape that is thermally connected to the back surface of green light source 612, and is a heat receiving section that receives heat generated in green light source 612.

[0045] As shown in FIGS. 3 and 4, third heat spreader 813 has a flat plate shape that is thermally connected to the rear surface of blue light source 613, and is a heat receiving section that receives heat generated in blue light source 613.

[0046] Although the first to third heat spreaders 813 are configured as members independent of each other, the present invention is not limited to this, and they may be configured as one member common to the red, green, and blue light sources 611 to 613.

[0047] The first heat dissipation section 821 is disposed inside the duct 71, and is configured of a plurality of plate-shaped fins whose front and back surfaces are aligned along the flow path PT (along the XZ plane). That is, the first heat dissipation section 821 is disposed below (on the -Z axis direction side) the red, green, and blue light sources 611-613, the first to fourth lenses 621-624, and the first to third dichroic mirrors 631-633. The first heat dissipation section 821 dissipates heat generated in the red, green, and blue light sources 611-613 to the air flowing along the flow path PT.

[0048] The second heat dissipation section 822 is disposed inside the duct 71, and is configured of a plurality of plate-shaped fins whose front and back surfaces are aligned along the flow path PT (along the XZ plane). That is, the second heat dissipation section 822 is disposed below (on the -Z axis direction side) the red, green, and blue light sources 611-613, the first to fourth lenses 621-624, and the first to third dichroic mirrors 631-633. The second heat dissipation section 822 dissipates heat generated in the green and blue light sources 612, 613 to the air flowing along the flow path PT.

[0049] That is, the first and second heat dissipation portions 821 and 822 are formed from members independent of each other.

[0050] More specifically, the length of the fins constituting the first heat dissipation section 821 is longer than the length of the fins constituting the second heat dissipation section 822, as shown in Fig. 3 and Fig. 4. Also, the first heat dissipation section 821 is disposed at a position closer to the arrangement position of the red, green, and blue light sources 611 to 613 than the second heat dissipation section 822 (a position on the -Y axis direction side of the second heat dissipation section 822), as shown in Fig. 3. In addition, in the first and second heat dissipation sections 821 and 822, the tip end of the second heat dissipation section 822 on the upstream side (+X axis direction side) of the flow path PT is located downstream (-X axis direction side) of the tip end of the first heat dissipation section 821 on the upstream side (+X axis direction side) of the flow path PT. That is, the first and second heat dissipation sections 821 and 822 are disposed in a stepped shape as a whole, with the first heat dissipation section 821 protruding toward the upstream side (+X axis direction side) of the flow path PT. As a result, the air that does not pass through the first heat radiating portion 821, out of the air that flows through the flow path PT, flows through the second heat radiating portion 822.

[0051] Here, the spacing between the multiple fins constituting second heat dissipation portion 822 is narrower than the spacing between the multiple fins constituting first heat dissipation portion 821.

[0052] 4, one end of the first heat pipe 831 is thermally connected to the first heat spreader 811, extends downward (to the -Z-axis direction) from the one end, and is bent by approximately 90° to extend in the +Y-axis direction. The other end of the first heat pipe 831 is thermally connected to the first heat dissipation section 821 while passing through a plurality of fins that configure the first heat dissipation section 821. The first heat pipe 831 transfers heat from the first heat spreader 811 (heat from the red light source 611) from one end to the other end.

[0053] 4, one end of the second heat pipe 832 is thermally connected to the second heat spreader 812, extends downward (toward the -Z-axis direction) from the one end, and is bent at approximately 90° to extend in the +Y-axis direction. The other end of the second heat pipe 832 is thermally connected to the first and second heat dissipation sections 821 and 822 while penetrating the multiple fins constituting the first heat dissipation section 821 and the multiple fins constituting the second heat dissipation section 822, respectively. The second heat pipe 832 transfers heat from the second heat spreader 812 (heat from the green light source 612) from one end to the other end.

[0054] 4, one end of the third heat pipe 833 is thermally connected to the third heat spreader 813, extends downward (toward the -Z-axis direction) from the one end, and then bends at approximately 90° to extend in the +Y-axis direction. The other end of the third heat pipe 833 is thermally connected to the first and second heat dissipation sections 821 and 822 while penetrating the multiple fins constituting the first heat dissipation section 821 and the multiple fins constituting the second heat dissipation section 822, respectively. The third heat pipe 833 transfers heat from the third heat spreader 813 (heat from the blue light source 613) from one end to the other end.

[0055] Here, the allowable thermal resistance of the heat sink in red light source 611, which is calculated from the difference between the maximum junction temperature (first temperature) and the ambient temperature, and the amount of heat generated, is greater than the allowable thermal resistance of the heat sink in green light source 612, which is calculated from the difference between the maximum junction temperature (third temperature) and the ambient temperature, and the amount of heat generated. More specifically, the allowable thermal resistance is the value obtained by dividing the difference [°C] between the maximum junction temperature and the ambient temperature by the amount of heat generated [W].

[0056] According to the above-described first embodiment, the following effects are achieved. In the light source device 6 according to the first embodiment, the heat sink 8 includes a first heat dissipation section 821 that is disposed on the air flow path PT and dissipates heat from the red and green light sources 611 and 612 to the air, and a second heat dissipation section 822 that is disposed on the air flow path PT and dissipates heat from the green light source 612 to the air. The allowable thermal resistance of the heat sink in the red light source 611, which is calculated from the difference between the maximum junction temperature (first temperature) and the ambient temperature and the amount of heat generated, is greater than the allowable thermal resistance of the heat sink in the green light source 612, which is calculated from the difference between the maximum junction temperature (third temperature) and the ambient temperature and the amount of heat generated. The first and second heat dissipation sections 821 and 822 are arranged in a stepped shape as a whole, with the first heat dissipation section 821 protruding toward the upstream side (+X-axis direction side) of the air flow path PT. As a result, the air that does not pass through the first heat dissipation section 821 flows through the second heat dissipation section 822, among the air that follows the air flow path PT. Therefore, the heat of green light source 612, which generates a large amount of heat, can be sufficiently dissipated, and there is no increase in the temperature of red light source 611 adjacent to green light source 612. In other words, red light source 611 can be maintained at an appropriate temperature, and the light emission efficiency of red light source 611 can be maintained at a good level. Therefore, according to light source device 6 of the first embodiment, while using first heat dissipation section 821 common to red and green light sources 611, 612, heat from red and green light sources 611, 612 can be efficiently dissipated.

[0057] In particular, the spacing between the multiple fins constituting second heat dissipation section 822 is narrower than the spacing between the multiple fins constituting first heat dissipation section 821. This increases the flow rate of air flowing between the multiple fins constituting second heat dissipation section 822, and allows the temperature of green light source 612 to be preferentially reduced. As a result, the temperature of red light source 611 adjacent to green light source 612 can also be reduced.

[0058] (Variation 1-1) Fig. 5 and Fig. 6 are diagrams for explaining Modification 1-1 of the embodiment 1. Specifically, Fig. 5 is a diagram corresponding to Fig. 3. Fig. 6 is a diagram corresponding to Fig. 4. In the above-mentioned first embodiment, the first heat dissipation section 821 is disposed at a position closer to the arrangement position of the red, green, and blue light sources 611-613 than the second heat dissipation section 822 (at a position closer to the -Y axis side than the second heat dissipation section 822), but this is not limited thereto. As in the present modified example 1-1 shown in Figs. 5 and 6, the second heat dissipation section 822 may be disposed at a position closer to the arrangement position of the red, green, and blue light sources 611-613 than the first heat dissipation section 821 (at a position closer to the -Y axis side than the first heat dissipation section 821).

[0059] According to the present modified example 1-1 explained above, in addition to the same effects as those of the above-mentioned embodiment 1, the following effects are achieved. In this modified example 1-1, compared to the configuration in the above-described embodiment 1, second heat dissipation section 822 is disposed at a position closer to the positions of red, green, and blue light sources 611-613 than first heat dissipation section 821. This makes it possible to cool green light source 612 with priority.

[0060] (Embodiment 2) Next, a second embodiment will be described. In the following description, the same components as those in the above-described first embodiment are given the same reference numerals, and detailed description thereof will be omitted or simplified. 7 to 9 are diagrams illustrating the configuration of the heat sink 8 according to the second embodiment. Specifically, FIG. 7 is a diagram corresponding to FIG. 4. FIG. 8 is a diagram of the heat sink 8 viewed from the +X-axis direction side. FIG. 9 is a diagram of the heat sink 8 viewed from the +Y-axis direction side. For ease of explanation, the second heat dissipation portion 822 is omitted in FIG. 9.

[0061] In the second embodiment, the configuration of the heat sink 8 is changed from that of the first embodiment. More specifically, in the heat sink 8 according to the first embodiment, the first to third heat pipes 831 to 833 are arranged in the first heat dissipation section 821 at first to third positions P1 to P3 on a virtual line LV along the X-axis direction perpendicular to the flow path PT, as shown in FIG. 9. That is, the height positions of the first to third positions P1 to P3 are all the same. The X-axis direction corresponds to the first direction according to the present invention. In contrast, in the heat sink 8 according to the second embodiment, the first and second heat pipes 831 and 832 are arranged in the first heat dissipation section 821 at first and second positions P1' and P2', respectively, which are spaced apart from each other along the Z-axis direction. More specifically, the height position of the first position P1 is higher than the height position of the second position P2. The Z-axis direction corresponds to the second direction according to the present invention. In addition, the second heat pipe 832 is disposed at the third position P3 in the first heat dissipation portion 821, similarly to the first embodiment described above.

[0062] According to the above-described second embodiment, in addition to the same effects as those of the first embodiment, the following effects are achieved. In the light source device 6 according to the second embodiment, the first and second heat pipes 831, 832 are arranged at the first and second positions P1', P2' in the first heat dissipation section 821, which are spaced apart from each other along the Z-axis direction. This makes it possible to realize a structure in which air heated by the first heat dissipation section 821 (red light source 611) connected to the first heat pipe 831 on the upstream side of the flow path PT is unlikely to be introduced into the second heat pipe 832 arranged on the downstream side of the flow path PT. In other words, a structure that makes it easy to lower the temperature of the green light source 612 is realized, and it becomes possible to also lower the temperature of the red light source 611 adjacent to the green light source 612.

[0063] (Variation 2-1) Fig. 10 and Fig. 11 are diagrams for explaining a modified example 2-1 of the embodiment 2. Specifically, Fig. 10 corresponds to Fig. 3 and is a plan view showing the overall configuration of a cooling unit 7 according to the modified example 2-1. Fig. 11 corresponds to Fig. 7. In the above-mentioned second embodiment, a separator 9 may be used as in the present modified example 2-1 shown in FIGS.

[0064] 10 and 11, the separator 9 is disposed in a state where it is inserted into a portion of the first heat dissipation section 821 that protrudes from the second heat dissipation section 822 toward the upstream side of the flow path PT. The separator 9 divides the air flowing through the flow path PT in the Z-axis direction into a first space SP1 (FIG. 11) on the first heat pipe 831 side and a second space SP2 (FIG. 11) on the second heat pipe 832 side, and distributes the air.

[0065] According to the present modified example 2-1 explained above, in addition to the same effects as those of the above-mentioned embodiment 2, the following effects are achieved. In this modified example 2-1, the above-mentioned separator 9 is adopted. Therefore, a larger amount of fresh air can be introduced into the second heat pipe 832 disposed downstream of the flow path PT. That is, a structure that can easily lower the temperature of the green light source 612 is realized, and it is also possible to lower the temperature of the red light source 611 adjacent to the green light source 612.

[0066] (Variation 2-2) 12 is a diagram for explaining a modified example 2-2 of the embodiment 2. Specifically, FIG. 12 corresponds to FIG. In the first heat dissipation section 821 according to the above-mentioned modified example 2-1, as in the present modified example 2-2 shown in Fig. 12, among the portion protruding from the second heat dissipation section 822 toward the upstream side (+X-axis direction side) of the flow path PT, the portion on the second space SP2 side divided by the separator 9 may be omitted. Note that the separator 9 may or may not be provided.

[0067] Even when the configuration of the present modified example 2-2 described above is adopted, the same effects as those of the above modified example 2-1 are achieved.

[0068] (Variation 2-3) 13 is a diagram for explaining a modified example 2-3 of the embodiment 2. Specifically, FIG. 13 corresponds to FIG. The multiple fins constituting the second heat dissipation section 822 of the above-mentioned modified example 2-2 may be changed to the same shape as the multiple fins constituting the first heat dissipation section 821 of the above-mentioned modified example 2-2, as in modified example 2-3 shown in Figure 13.

[0069] Even when the configuration of the present modified example 2-3 described above is adopted, the same effects as those of the above modified example 2-2 are achieved.

[0070] (Other embodiments) Although the embodiments for carrying out the present invention have been described above, the present invention should not be limited to only the above-mentioned Embodiments 1 and 2 and Modifications 1-1, and 2-1 to 2-3.

[0071] In the above-mentioned embodiments 1 and 2 and modifications 1-1, 2-1 to 2-3, the light source device according to the present invention is mounted on an endoscope system 1 using a flexible endoscope, but the present invention is not limited to this and may be mounted on an endoscope system using a rigid endoscope. Also, the light source device according to the present invention may be mounted on an observation system using a surgical microscope that enlarges and captures an image of a predetermined field of view inside a subject (inside a living body) or on a surface of a subject (surface of a living body).

[0072] In the above-described first and second embodiments and modifications 1-1, 2-1 to 2-3, the first light-emitting element according to the present invention is the red light source 611, and the second light-emitting element according to the present invention is the green light source 612, but this is not limited to the above. The wavelength bands of the light emitted from the first and second light-emitting elements are not limited to the wavelength bands described in the above-described first and second embodiments and modifications 1-1, 2-1 to 2-3, and may be other wavelength bands.

[0073] In the above-mentioned embodiments 1 and 2 and variants 1-1, 2-1 to 2-3, the first and second heat dissipation sections of the present invention are not limited to those formed of a plurality of plate-shaped fins, but may be formed of a plurality of protrusion-like fins or may be formed in a block shape.

[0074] In the above-described first and second embodiments and modifications 1-1, 2-1 to 2-3, the following modifications 3-1 to 3-3 may be adopted.

[0075] (Variation 3-1) For ease of explanation, the red, green, and blue light sources 611-613 will be collectively referred to as a light-emitting element 61. Further, the first to third heat spreaders 811-813 will be collectively referred to as a heat spreader 81.

[0076] Fig. 14 and Fig. 15 are diagrams for explaining Modification 3-1 of the first and second embodiments and Modifications 1-1, 2-1 to 2-3. Specifically, Fig. 14 is a diagram of a light emitting element 61 as viewed from the front side (light emission side). Fig. 15 is a diagram of a fixing structure of the light emitting element 61 to the heat spreader 81 as viewed from the front side. In the above-mentioned embodiments 1 and 2 and modifications 1-1, 2-1 to 2-3, the fixing structure of the light emitting element 61 to the heat spreader 81 may be the fixing structure of the present modification 3-1 shown in FIG.

[0077] 14, the light emitting element 61 has a configuration in which a chip 61B having a light emitting surface 61B1 for emitting light is mounted on a circuit board 61A. A pair of positioning holes 61A1 penetrating the front and back of the circuit board 61A are provided at two positions on either side of the light emitting surface 61B1 on the circuit board 61A. A pair of mounting holes 61A2 penetrating the front and back of the circuit board 61A are provided at two positions on either side of the light emitting surface 61B1 on the circuit board 61A.

[0078] In the present modified example 3-1, a frame member 10 is used as a fixing structure for the light emitting element 61 to the heat spreader 81, as shown in FIG.

[0079] The frame member 10 is made of a plate body, and holds the light emitting element 61 between itself and the heat spreader 81. In the frame member 10, an opening 101 is provided at a position facing the light emitting surface 61B1, as shown in Fig. 15, which penetrates from the front to the back and through which the light emitted from the light emitting surface 61B1 passes. That is, the frame member 10 has a square shape. In addition, in the frame member 10, insertion holes 102 are provided at positions facing the pair of mounting holes 61A2, which penetrate from the front to the back and through which fixing members SC such as screws are inserted.

[0080] The frame member 10 described above is preferably made of a resin having insulating properties and resistance to ultraviolet light. Examples of the resin include PEEK (polyether ether ketone), polycarbonate, and acrylic.

[0081] The light emitting element 61 is attached to the heat spreader 81 as follows. First, an operator inserts a positioning pin (not shown) into a pair of positioning holes 61A1 in the light-emitting element 61, and also inserts the positioning pin into a pair of positioning holes (not shown) formed in the heat spreader 81. This allows the light-emitting element 61 to be optically positioned.

[0082] Next, the worker places the frame member 10 against the front side of the light-emitting element 61, inserts the fixing members SC into the pair of insertion holes 102 in the frame member 10 and the pair of mounting holes 61A2 in the light-emitting element 61, and fastens the fixing members SC to the heat spreader 81. As a result, the light-emitting element 61 is fixed to the heat spreader 81.

[0083] According to the present modified example 3-1 described above, in addition to the same effects as those of the above-mentioned embodiments 1 and 2 and modified examples 1-1, 2-1 to 2-3, the following effects are achieved. In this modified example 3-1, the above-mentioned frame member 10 is adopted. Therefore, the fastening force of the fixing member SC can be dispersed by the frame member 10, and the back surface of the light emitting element 61 can be uniformly pressed against the heat spreader 81. As a result, the contact thermal resistance between the light emitting element 61 and the heat spreader 81 can be reduced, and the heat of the light emitting element 61 can be effectively dissipated to the heat spreader 81.

[0084] A thermally conductive sheet such as a TIM (Thermal Interface Material) may be interposed between the rear surface of the light emitting element 61 and the heat spreader 81. The same applies to modified examples 3-2 and 3-3 described below.

[0085] (Variation 3-2) 16 is a diagram for explaining a modified example 3-2 of the embodiments 1 and 2 and the modified examples 1-1 and 2-1 to 2-3. Specifically, FIG. 16 is a diagram corresponding to FIG. In the above-mentioned variant example 3-1, if a sensor 11 (Figure 16) that detects a portion of the light emitted from the light-emitting surface 61B1 is attached to the light-emitting element 61, the frame member 10 related to this variant example 3-2 shown in Figure 16 may be adopted.

[0086] 16, in the frame member 10 according to the present modified example 3-2, a part of the edge portion of the opening portion 101 is cut out in order to avoid mechanical interference with the sensor 11. In other words, the frame member 10 according to the present modified example 3-2 has a U-shape.

[0087] Even when the configuration of the present modified example 3-2 described above is adopted, the same effects as those of the above modified example 3-1 are achieved.

[0088] (Variation 3-3) 17 and 18 are diagrams for explaining modified example 3-3 of embodiments 1 and 2 and modified examples 1-1, 2-1 to 2-3. Specifically, FIG. 17 is a perspective view of a fixing structure of a light-emitting element 61 to a heat spreader 81, as seen from the front side. For ease of explanation, FIG. 17 shows a configuration using four light-emitting elements 61. Also, in FIG. 17, the heat spreader 81 is a common member for the four light-emitting elements 61. FIG. 18 is a cross-sectional view taken along line AA in FIG. 17. In the above-described first and second embodiments and modified examples 1-1, 2-1 to 2-3, the fixing structure of the light emitting element 61 to the heat spreader 81 may be the fixing structure of modified example 3-3 shown in FIGS.

[0089] In this modified example 3-3, as shown in FIGS. 17 and 18, a frame member 10 (FIG. 18) and a pressing member 12 are used as a fixing structure for the light emitting element 61 to the heat spreader 81.

[0090] Here, as shown in Fig. 17, a sensor 11 is attached to the light-emitting element 61 in the same manner as in the above-mentioned modified example 3-2. The frame member 10 in this modified example 3-3 has the same shape as in the above-mentioned modified example 3-2. That is, the frame member 10 in this modified example 3-3 is provided for each light-emitting element 61.

[0091] Moreover, the frame member 10 according to the present modified example 3-3 is made of an elastomer having elasticity, such as fluororubber.

[0092] Furthermore, in the frame member 10 according to the present modified example 3-3, an insertion hole 103 is provided at a position facing the pair of positioning holes 61A1, penetrating from the front to the back and into which a positioning pin 121 is inserted (FIG. 18).

[0093] 17, the pressing member 12 according to the present modification 3-3 is provided as a common member for the four light emitting elements 61. Note that the pressing member 12 may be provided for each light emitting element 61.

[0094] The pressing member 12 is formed of a plate body, and holds the light emitting element 61 and the frame member 10 between itself and the heat spreader 81 .

[0095] As shown in FIG. 18, on the back surface of the pressing member 12, positioning pins 121 are provided at positions facing the pair of positioning holes 61A1 so as to protrude toward the back surface side.

[0096] 17, an opening 122 is provided in the pressing member 12 at a position facing the light-emitting surface 61B1, penetrating the pressing member 12 from front to back and through which the light emitted from the light-emitting surface 61B1 passes. Here, in the pressing member 12, similar to the frame member 10, a part of the edge of the opening 122 is cut out in order to avoid mechanical interference with the sensor 11.

[0097] Furthermore, as shown in FIG. 18, the pressing member 12 is provided with insertion holes 123 at positions avoiding the light emitting elements 61 and the frame member 10, which penetrate from the front to the back and through which the fixing members SC are inserted.

[0098] The light emitting element 61 is attached to the heat spreader 81 as follows. First, the worker inserts the positioning pin 121 into the pair of insertion holes 102 in the frame member 10 and the pair of positioning holes 61A1 in the light-emitting element 61, and also inserts the positioning pin 121 into the pair of positioning holes 810 (FIG. 18) formed in the heat spreader 81. This allows the light-emitting element 61 to be optically positioned.

[0099] Next, the worker inserts the fixing members SC into the pair of insertion holes 123 in the pressing member 12, and fastens the fixing members SC to the heat spreader 81. In this way, the light emitting element 61 is fixed to the heat spreader 81.

[0100] Even when the configuration of the present modified example 3-3 described above is adopted, the same effects as those of the above modified examples 3-1 and 3-2 are achieved. [Explanation of symbols]

[0101] 1 Endoscope system 2 Endoscope 3 Display device 4 Processing Equipment 5. Control device 6 Light source device 7 Cooling Unit 8 Heat sink 9 Separator 10 Frame members 11 Sensors 12 Holding member 21 Insertion section 22 Control section 23 Universal Code 24 Connector part 25 Light Guide 26 Lighting Lens 27 Imaging Device 51 Control section 52 Storage section 53 Input section 61 Light emitting element 61A Circuit Board 61A1 Positioning hole 61A2 Mounting hole 61B Chip 61B1 Light emitting surface 65 Case 71 Duct 72 Cooling fan 81 Heat spreader 101 Opening 102 Insertion hole 103 Insertion hole 121 Locating pin 122 Opening 123 Insertion hole 611 Red light source 612 Green light source 613 Blue light source 621 First Lens 622 2nd lens 623 3rd lens 624 4th lens 631 1st Dichroic Mirror 632 2nd Dichroic Mirror 633 3rd Dichroic Mirror 651,652 side wall 810 Positioning hole 811 1st heat spreader 812 2nd Heat Spreader 813 3rd Heat Spreader 821 1st heat dissipation section 822 2nd heat dissipation section 831 1st heat pipe 832 Second Heat Pipe 833 3rd heat pipe LV Virtual Line P1,P1´ 1st position P2,P2´ 2nd position P3 3rd position PT flow path SC Fixing material SP1 1st space SP2 2nd space

Claims

1. A first light-emitting element; A second light-emitting element; a heat sink that dissipates heat from the first light emitting element and the second light emitting element, The heat sink is a first heat dissipation section that is disposed on a flow path of a fluid and dissipates heat from the first light emitting element and the second light emitting element to the fluid; a second heat dissipation unit that is disposed on the flow path and dissipates heat from the second light emitting element to the fluid; The allowable thermal resistance of the heat sink in the first light emitting element, which is calculated from the difference between the maximum junction temperature and the ambient temperature and the amount of heat generated, is The light source device has a heat resistance greater than the allowable heat resistance of the heat sink in the second light emitting element, the heat resistance being determined from the difference between the maximum junction temperature and the ambient temperature and the amount of heat generated.

2. The second heat dissipation portion has The light source device according to claim 1 , wherein the fluid flows without passing through the first heat dissipation portion.

3. The first heat dissipation portion and the second heat dissipation portion are 3. The light source device according to claim 2, wherein an upstream end of the flow path in the second heat dissipation portion is located downstream of an upstream end of the flow path in the first heat dissipation portion, and the light source device is arranged in a stepped shape as a whole.

4. The first light emitting element is The light source device according to claim 2 , wherein the second light emitting element is disposed at a position corresponding to an upstream side of the flow path with respect to the second light emitting element.

5. The heat sink is a first heat pipe that thermally connects the first light emitting element and the first heat dissipation portion; The light source device according to claim 1 , further comprising a second heat pipe thermally connecting the second light emitting element to the first heat dissipation portion and the second heat dissipation portion.

6. The first heat pipe and the second heat pipe are The light source device according to claim 5, wherein in the first heat dissipation section, two first positions and two second positions on a virtual line along a first direction perpendicular to the flow path are respectively arranged at positions spaced apart from each other along a second direction perpendicular to the flow path and the first direction.

7. The first heat dissipation portion is It is composed of multiple fins, The first heat dissipation portion has The light source device according to claim 6 , further comprising a separator for dividing the fluid in the second direction and circulating it between a first space on the first heat pipe side and a second space on the second heat pipe side.

8. The first heat dissipation portion and the second heat dissipation portion are 2. The light source device according to claim 1, which is constituted by members independent of each other.

9. The first heat dissipation portion and the second heat dissipation portion are 2. The light source device according to claim 1, wherein each of the light sources is constituted by a plurality of fins.

10. The spacing between the fins constituting the second heat dissipation portion is The light source device according to claim 9 , wherein the distance between the fins is narrower than the distance between the fins that constitute the first heat dissipation portion.

11. The first light emitting element is The light source device according to claim 1 , wherein the maximum junction temperature of the first light emitting element is lower than that of the second light emitting element.

12. The second light emitting element is The light source device according to claim 1 , wherein the first light emitting element generates more heat than the second light emitting element.

13. The first light emitting element is 2. The light source device according to claim 1, wherein the light emitting element emits red light.

14. The second light emitting element is 2. The light source device according to claim 1, wherein the light emitting element emits green light.

15. The first light emitting element and the second light emitting element are 2. The light source device according to claim 1, which is a semiconductor light emitting element.

16. A cooling method for cooling a first light emitting element and a second light emitting element thermally connected to a heat sink having a first heat dissipation portion and a second heat dissipation portion, comprising: Dissipating heat from the first light emitting element and the second light emitting element to the first heat dissipation section disposed on a flow path of a fluid; The heat of the second light emitting element is dissipated to the second heat dissipation section disposed on a flow path of the fluid; The allowable thermal resistance of the heat sink in the first light emitting element, which is calculated from the difference between the maximum junction temperature and the ambient temperature and the amount of heat generated, is A cooling method in which the amount of heat generated is greater than the allowable thermal resistance of the heat sink in the second light emitting element, the allowable thermal resistance being calculated from the difference between the maximum junction temperature and the ambient temperature and the amount of heat generated.

17. A first light-emitting element; A second light-emitting element; a heat sink that dissipates heat from the first light emitting element and the second light emitting element, The heat sink is a first heat dissipation section that is disposed on a flow path of a fluid and dissipates heat from the first light emitting element and the second light emitting element to the fluid; a second heat dissipation portion that is disposed on the flow path and dissipates heat of the second light emitting element to the fluid; a first heat pipe that thermally connects the first light emitting element and the first heat dissipation portion; a second heat pipe that thermally connects the second light emitting element to the first heat dissipation portion and the second heat dissipation portion;

18. The first light emitting element is The light source device according to claim 17 , wherein the maximum junction temperature is lower than that of the second light emitting element.

19. The second light emitting element is The light source device according to claim 17 , wherein the first light emitting element generates more heat than the second light emitting element.

20. The allowable thermal resistance of the heat sink in the first light emitting element is calculated from the difference between the maximum junction temperature of the first light emitting element and the ambient temperature and the amount of heat generated by the first light emitting element, and is given by: The light source device according to claim 17 , wherein the difference between the maximum junction temperature of the second light emitting element and the ambient temperature is greater than the allowable thermal resistance of the heat sink in the second light emitting element, which is calculated from the amount of heat generated by the second light emitting element.

Images