Electronic apparatus

Abstract

To allow efficient radiation of heat from a movable heating element, and prevent an increase in drive load when moving the heating element.SOLUTION: An imaging apparatus 100 comprises: a heat sink 80 that is fixed to an apparatus body; an image pick-up device 50 that is a heating element; and an image shake correction unit 201 that moves the image pick-up device 50 in a plane orthogonal to an imaging surface, and the image shake correction unit 201 has a holding member 203 that holds the image pick-up device 50. The holding member 203 is provided with a ring-shaped convex part 203a not in contact with the heat sink 80 so as to surround an area of part of a space between the heat sink 80 and the holding member 203. A top face of the convex part 203a is provided with a water-repellent surface 203b, and liquid 300 is held in a space surrounded by the convex part 203a. Heat generated in the image pick-up device 50 is transmitted to the heat sink 80 through the liquid 300, thereby cooling the image pick-up device 50.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an electronic device having a heat transfer mechanism using a liquid. [Background technology]

[0002] In recent years, the performance of small electronic devices has improved dramatically due to advances in semiconductor technology. For example, in portable electronic devices such as smartphones and digital cameras, the performance of semiconductor devices such as processors (CPUs and MPUs) and image sensors has improved significantly.

[0003] In these electronic devices, the amount of heat generated by the semiconductor devices increases during use. Therefore, in order to prevent breakdowns in the electronic devices and to ensure the safety of users who operate the electronic devices, it is necessary to quickly dissipate the heat generated in the semiconductor devices to the outside.

[0004] In electronic devices that do not have a forced cooling mechanism such as an electric fan, a configuration is generally adopted in which heat generated inside is diffused throughout the entire housing and released to the outside air. In this case, it is important to construct a highly efficient heat transfer path from the heat generating body to the entire housing. Here, when the heat generating body is a movable body, in a configuration in which a solid heat conducting member is directly contacted or connected to the heat source, there is a problem that the driving load for moving the heat generating body increases due to the heat conducting member. Therefore, for example, Patent Document 1 discloses a technology that provides a bendable heat transfer sheet and is arranged so that the thickness direction of the heat transfer sheet is the same as the moving direction of the heat generating body, which is a movable body, thereby suppressing the increase in the driving load for moving the heat generating body and ensuring a good heat transfer path. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 202811 Brochure Summary of the Invention [Problem to be solved by the invention]

[0006] In the above-mentioned Patent Document 1, the cross-sectional area of ​​the heat transfer path is small because a sheet material is used, and therefore the amount of heat transfer is limited. In response to this problem, a configuration has been proposed in which multiple sheet materials are stacked in the thickness direction to increase the amount of heat transfer, but in this case, the driving load for moving the heating element increases.

[0007] An object of the present invention is to provide an electronic device that enables efficient heat dissipation from a movable heat generating element while suppressing an increase in the drive load when the heat generating element is moved. [Means for solving the problem]

[0008] The electronic device of the present invention comprises a device main body, a heating element arranged to be movably relative to the device main body, a water-repellent portion arranged to surround a partial area of ​​the space formed between the device main body and the heating element, and a liquid held in the area and transferring heat from the heating element to the device main body, and is characterized in that the water-repellent portion is arranged on at least one of the surfaces forming the space between the device main body and the heating element without contacting the other surface. Effect of the Invention

[0009] According to the present invention, it is possible to provide an electronic device that enables efficient heat dissipation from a movable heat generating element and suppresses an increase in the drive load when the heat generating element is moved. [Brief description of the drawings]

[0010] [Figure 1] 1 is an external perspective view of an imaging device according to a first embodiment. [Diagram 2] 1A and 1B are an external perspective view and an exploded perspective view of an imaging unit included in an imaging device; [Diagram 3] 2A and 2B are a front view and a cross-sectional view taken along the line AA of the imaging unit. [Figure 4] FIG. 4 is an enlarged view of a region R in FIG. [Diagram 5]3A and 3B are schematic diagrams showing a rear perspective view of an imaging element holding member provided in the imaging unit and a configuration of a water-repellent surface thereof; [Figure 6] FIG. 11 is a perspective view of a motor and a heat transfer cylindrical member in a second embodiment. [Figure 7] 1A is a top view of a motor unit in which a motor and a heat transfer cylindrical member are combined, and a cross-sectional view taken along the arrow BB shown in the top view. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0012] First Embodiment In digital cameras, which are one example of electronic devices, an increasing number of models are equipped with a function to correct image blur by moving or rotating the image sensor in a plane parallel to the imaging surface. Since the image sensor is one of the main heat generating bodies in a digital camera, it is necessary to quickly dissipate the heat generated by the image sensor to the outside without increasing the driving load for the image blur correction operation. Therefore, in the first embodiment, a digital camera (imaging device) that takes still images and moving images will be taken as an example of an electronic device according to the present invention.

[0013] FIG. 1 is an external perspective view of an imaging device 100 according to the first embodiment, where FIG. 1(a) is a perspective view of the imaging device 100 seen from the front, and FIG. 1(b) is a perspective view of the imaging device 100 seen from the rear.

[0014] For convenience of explanation, an X-axis, a Y-axis, and a Z-axis are defined which are mutually orthogonal as shown in FIG. 1. The Z-axis is orthogonal to the imaging surface of the image sensor 50, and the direction from the imaging device 100 to the subject (not shown) is defined as the positive direction (+Z). The X-axis is orthogonal to the Z-axis in a horizontal plane when the Z-axis is parallel to the horizontal plane, and the direction from left to right when the imaging device 100 is viewed from the +Z side is defined as the positive direction (+X). The Y-axis is parallel to the vertical direction when the X-axis and the Z-axis are in a horizontal plane, and the direction from bottom to top when the imaging device 100 is viewed from the +Z side is defined as the positive direction (+Y). The X-direction, the Y-direction, and the Z-direction are the width direction, the height direction, and the thickness (depth) direction of the imaging device 100, respectively.

[0015] A lens mount 60 that allows an optical lens (not shown) to be attached and detached is provided on the front surface of the imaging device 100. The lens mount 60 has electrical contacts 61, and when the optical lens is attached to the lens mount 60, the electrical contacts 61 are connected to the electrical contacts of the optical lens. This allows power to be supplied from the imaging device 100 to the optical lens, and also enables transmission and reception of various control signals between a control circuit of the imaging device 100 and a control circuit of the optical lens.

[0016] An imaging element 50 is disposed inside the imaging device 100. An optical lens attached to a lens mount 60 forms an optical image of a subject on the imaging surface of the imaging element 50. The imaging element 50 is, for example, a CMOS sensor, and generates image data by converting the optical image formed on the imaging surface into an electrical signal by photoelectric conversion. The imaging device 100 includes a so-called in-camera image stabilization unit, and is capable of correcting a user's hand shake or the like by moving and rotating the imaging element 50 in the XY plane. The image stabilization unit will be described in detail later.

[0017] A grip 40 protruding toward the +Z side is provided on the left side of the imaging device 100 so that a user can grip the imaging device 100 with his / her right hand. A shutter button 10 and a video recording button 11 are provided on the top surface of the grip 40. A user can take a still image by pressing the shutter button 10, and can start and stop video recording by pressing the video recording button 11. In addition, a media slot section 62 is provided on the left side surface (the -X side surface of the grip 40) of the imaging device 100. The media slot section 62 has a media slot (not shown) that stores a recording medium (not shown) such as an SD card or a CF card, and when the cover of the media slot section 62 is opened, the recording medium can be inserted and removed from the media slot.

[0018] A power switch 12 for switching on / off the power supply of the imaging device 100 is disposed on the +X side of the upper surface of the imaging device 100. The imaging device 100 is driven by a battery (not shown) housed inside the grip portion 40.

[0019] An eyepiece 20 is provided at the top of the rear side of the imaging device 100, and an electronic viewfinder (not shown) is provided inside the eyepiece 20. When shooting, a live view image is displayed on the electronic viewfinder, and the user can check the subject and composition by looking into the eyepiece 20 and viewing the live view image. The electronic viewfinder can also display a menu screen and shooting results.

[0020] A liquid crystal display 22 is provided on the rear surface of the imaging device 100. The liquid crystal display 22 can display the same information as the electronic viewfinder 21. The liquid crystal display 22 also has a touch panel function, and intuitive operations can be performed by touching the display surface.

[0021] An interface unit 64 consisting of a group of terminals for connecting to various external devices is provided on the right side surface of the imaging device 100. When the cover of the interface unit 64 is open, various external devices such as accessories, a personal computer, and an external monitor can be connected using a USB cable or an HDMI (registered trademark) cable, and a microphone and headphones can also be connected.

[0022] Note that still image data and video data acquired by the shooting operation of the imaging device 100 are basically stored in a recording medium housed in the imaging device 100. Alternatively, the still image data and video data may be stored in an external device connected via the interface unit 64. For example, by connecting a storage device with a larger capacity than the upper limit storage capacity of the recording medium that can be housed in the imaging device 100 to the interface unit 64, it becomes possible to shoot videos for a longer period of time, for example.

[0023] Next, the configuration of the imaging element 50 and its periphery will be described. Fig. 2(a) is an external perspective view showing the configuration of the imaging unit 200, and Fig. 2(b) is an exploded perspective view of the imaging unit 200.

[0024] The imaging unit 200 is composed of an imaging element 50 and an image blur correction unit 201 that moves the imaging element 50 in a plane perpendicular to the imaging surface. A heat sink 80 is disposed on the rear side (-Z side) of the imaging unit 200. The heat sink 80 is made of a metal with high thermal conductivity such as an aluminum alloy, and is fixed to the housing (device body) of the imaging device 100. The heat sink 80 has the function of cooling the imaging element 50 (suppressing a rise in temperature) by diffusing heat generated by the imaging element 50 to the housing of the imaging device 100.

[0025] The image blur correction unit 201 has an image sensor holding member 203 (hereinafter referred to as "holding member 203") that holds the image sensor 50 and also holds a first drive coil 210, a second drive coil 220, and a third drive coil 230. The image blur correction unit 201 also has a front side yoke 202 and a rear side yoke 204 that are arranged to sandwich the holding member 203 in the Z-axis direction. A first front side magnet 211 is attached to the -Z side surface of the front side yoke 202 so as to face the first drive coil 210 in the Z direction, and a first rear side magnet 212 is attached to the +Z side surface of the rear side yoke 204. Similarly, a second front side magnet 221 is attached to the -Z side surface of the front side yoke 202 so as to face the second drive coil 220 in the Z direction, and a second rear side magnet 222 is attached to the +Z side surface of the rear side yoke 204. Similarly, a third front-side magnet 231 is attached to the -Z side surface of the front-side yoke 202 so as to face the third drive coil 230 in the Z direction, and a third back-side magnet 232 is attached to the +Z side surface of the back-side yoke 204. The front-side yoke 202 and the back-side yoke 204 are fixed to each other and to a device body (the housing of the imaging device 100) (not shown).

[0026] The magnetic field generated by energizing the first drive coil 210 and the second drive coil 220 and the magnetic field of the magnet facing these coils generate an electromagnetic force that drives the holding member 203 (image pickup element 50) in the Y direction in the XY plane. In addition, by controlling the energization of the first drive coil 210 and the second drive coil 220 (changing the current value) and changing the electromagnetic force in the Y direction acting on each coil, the holding member 203 can be tilted (rotated) by a certain angle in the XY plane. Similarly, the holding member 203 can be driven in the X direction by energizing the third drive coil 230. In this way, by controlling the energization of each coil, the image pickup element 50 can be moved in the XY plane relative to the device body as shown in FIG. 2(a), and the image blur can be corrected by moving the image pickup element 50 in the opposite direction to the image blur.

[0027] In this way, the front side yoke 202 and the rear side yoke 204 and the members attached thereto form a fixed part in the image shake correction unit 201. The holding member 203 and the members attached thereto form a movable part that is movable relative to the fixed parts.

[0028] Next, a configuration for dissipating heat generated by the imaging element 50 will be described. Fig. 3(a) is a front view of the imaging unit 200. Fig. 3(b) is a cross-sectional view taken along the arrow AA in Fig. 3(a). Fig. 4 is an enlarged view of a region R in Fig. 3(b). Fig. 5(a) is a perspective view of the holding member 203 as viewed from the rear.

[0029] As shown in FIG. 3(b), liquid 300 is poured into and held in a portion of the space formed between the holding member 203 and the heat sink 80. The liquid 300 is required to have a high thermal conductivity. It is also desirable that the liquid 300 has a low melting point so as to avoid problems when used in winter or in cold regions, and a high boiling point so as not to evaporate due to heat received from the image sensor 50. It is also desirable that the liquid 300 has a low viscosity so as not to increase the driving load during image stabilization driving. In view of these, for example, liquid metal is used as the liquid 300. When the image capture device 100 is in the normal posture (the posture in FIG. 1), the liquid 300 accumulates on the -Y side due to gravity.

[0030] 4 and 5(a), which are enlarged views of the region R on the -Y side of the liquid 300, the holding member 203 is provided with an annular convex portion 203a for accommodating and holding the liquid 300. In other words, the holding member 203 is provided with the convex portion 203a so as to surround a partial region of the space formed between the holding member 203 and the heat sink 80, and the liquid 300 is poured into and held in the region surrounded by the convex portion 203a. In the Z direction, the distance (gap) between the convex portion 203a and the heat sink 80 is smaller than in other parts of the holding member 203, but the upper surface of the convex portion 203a is not in contact with the heat sink 80.

[0031] The upper surface of the convex portion 203a (the surface facing the heat sink 80 on the -Z side) is a water-repellent portion having a water-repellent surface 203b that has been subjected to a water-repellent treatment. Also, a water-repellent portion having a water-repellent surface 80a is provided on the portion of the heat sink 80 facing the convex portion 203a, as shown in FIG.

[0032] An example of a water-repellent surface is a surface that has been processed to have a fine uneven shape formed by laser processing or the like, so as to obtain a lotus effect similar to how lotus leaves repel water. As shown in Fig. 4, a small clearance exists between the holding member 203 and the heat sink 80 in the Z direction, but the water repellency due to the uneven shape and the surface tension of the liquid 300 prevent the liquid 300 from leaking out.

[0033] In this embodiment, the convex portion 203a is provided so that its shape when viewed from the Z direction is annular (ring-shaped). If the convex portion were formed so that its shape when viewed from the Z direction was rectangular, there would be a high risk that the liquid 300 would leak out of the liquid 300 from the corner where the liquid 300 is pooled when the imaging unit 200 is driven in the diagonal direction of the imaging element 50 for image blur correction. In contrast, by providing the convex portion 203a in an annular shape, it is possible to reduce the risk of the liquid 300 leaking out depending on the driving direction of the imaging element 50.

[0034] Here, a description will be given of desirable aspects of the water-repellent surface 203b and the water-repellent surface 80a. In the water-repellent processing by laser processing described above, the contact angle of the liquid 300 to be water-repellent can be controlled by changing the height and interval of the uneven shape. Therefore, the water-repellent processing is performed so that the contact angle on the surface L<the contact angle on the surface M<the contact angle on the surface N. In other words, the contact angle becomes larger from the inner circumference to the outer circumference of the annular water-repellent surface 203b, and the force repelling the liquid 300 becomes larger. As a result, even if the liquid 300 tries to leak from the inside to the outside on the water-repellent surface 203b, a force that returns the liquid 300 to the inside of the water-repellent surface 203b acts on the liquid 300. In this way, the effect of preventing the liquid 300 from leaking out from the water-repellent surface 203b can be improved.

[0035] The configuration of water-repellent surface 80a is similar to that of water-repellent surface 203b. Control of the contact angle of liquid 300 is not limited to laser processing, but can be performed using a plurality of coating materials, attaching different water-repellent sheets, etc. Furthermore, although the three stages of surface L, surface M, and surface N have been described here, the change may be continuous (gradual) rather than stepwise.

[0036] FIG. 5(c) is a schematic diagram showing a water-repellent surface 203b_1 (water-repellent surface 80a_1) which is a modified example of the water-repellent surface 203b (water-repellent surface 80a). The imaging device 100 is often left in a normal position (the position in FIG. 1) during storage, and is often used in a normal position when in use. When the imaging device 100 is in the normal position, the liquid 300 accumulates on the -Y side due to gravity, and the liquid 300 is likely to leak out from the -Y side. Therefore, in the water-repellent surface 203b_1, the surfaces L1, M1, and N1 formed by shifting the center of a circle whose diameter increases from the inside to the outside gradually toward the -Y side on a straight line are used as the water-repellent surfaces. As in the example of FIG. 5(b), the water-repellent treatment is performed so that the contact angle on surface L1<the contact angle on surface M1<the contact angle on surface N1. By making the radial length of the water-repellent surface on the -Y side longer than in other directions, the leakage of the liquid 300 can be more reliably prevented. Furthermore, since the radial length of the water-repellent surface 203b_1 on the +Y side is the same as the radial length of the water-repellent surface in Figure 5 (b), leakage of liquid 300 from the +Y side is prevented even if the imaging device 100 is held upside down.

[0037] As shown in Fig. 3(b) and Fig. 4, a sealing member 310 is provided on the outer periphery of the convex portion 203a in order to prevent a decrease in the liquid 300 due to volatilization by sealing the liquid 300. This can be achieved by the sealing member 310. Since the liquid 300 does not leak to the outside of the convex portion 203a, the weight of the liquid 300 is not applied to the sealing member 310, but it is desirable to minimize the driving load of the image blur correction unit of the image sensor 50 caused by the sealing member 310. From this viewpoint, it is desirable to use a flexible material such as thin rubber or film for the sealing member 310.

[0038] The amount of liquid 300 filled is set to an amount that will thermally connect the holding member 203 and the heat sink 80 even if the imaging device 100 is in a position where the imaging surface of the imaging element 50 is parallel to the horizontal plane.

[0039] As described above, in the heat dissipation structure of this embodiment, the holding member 203 and the heat sink 80 are in contact with each other over a wide surface via the liquid 300, thereby realizing a large amount of heat transport from the holding member 203 to the heat sink 80. This allows the heat generated by the imaging element 50 to be efficiently transferred to the heat sink 80, thereby cooling the imaging element 50, in other words, suppressing the temperature rise of the imaging element 50. In addition, the liquid 300 is held by the action of the water-repellent surface 203b and the water-repellent surface 80a, so that the liquid 300 can move freely within the convex portion 203a. Therefore, the heat dissipation structure of this embodiment has the advantage of not substantially increasing the load during image blur correction due to the in-plane movement of the imaging element 50.

[0040] <Second embodiment> In the first embodiment, an image blur correction unit that moves the image sensor 50 in a plane has been described, and a configuration for dissipating heat generated by the image sensor 50, which is a heat-generating element, has been described. In contrast, in the second embodiment, a configuration for dissipating heat from a rotating heat-generating element will be described.

[0041] For example, one of the heat generating bodies in a drone is a brushless motor that rotates a propeller, and in an outer rotor type brushless motor, the outer cylinder rotates, so if a heat conductive member is brought into direct contact with the outer cylinder, the rotational drive load increases. Therefore, in the second embodiment, a motor unit equipped with an outer rotor type motor is taken up as an example of the electronic device according to the present invention.

[0042] FIG. 6(a) is an external perspective view of the motor 420. The motor 420 is an outer rotor type used in drones and the like, and has a cylindrical outer cylinder 420a that rotates integrally with the shaft 420b relative to a holding part (not shown). The motor 420 generates heat by continuous driving, but since the outer cylinder 420a rotates, if the outer cylinder 420a is brought into contact with a solid heat conductive member, frictional heat is generated and the driving load increases. Therefore, in the second embodiment, the motor unit 400 (see FIG. 7) is configured by combining the heat transfer cylindrical member 410 as a fixed part shown in FIG. 6(b) with the motor 420 as a movable part.

[0043] 6(b) is a perspective view of the heat transfer cylindrical member 410. The heat transfer cylindrical member 410 has annular convex portions 410a at two positions on its inner circumferential surface at a predetermined interval in the direction of the rotation axis of the motor 420 (the axial direction of the shaft 420b), and a water-repellent surface 410b is provided on the upper surface (the surface on the inner circumferential surface) of the convex portions 410a.

[0044] Fig. 7(a) is a top view (viewed from the longitudinal direction of the shaft 420b) of a motor unit 400 configured by mounting a heat transfer cylindrical member 410 to a motor 420. Fig. 7(b) is a cross-sectional view taken along the arrow BB shown in the top view of Fig. 7(a).

[0045] As shown in FIG. 7(b), two water-repellent surfaces 410b provided on the inner peripheral surface of the heat-transfer tubular member 410 are close to the outer peripheral surface of the outer cylinder 420a of the motor 420, and a liquid 500 having high thermal conductivity is poured between the two water-repellent surfaces 410b. The water-repellent surface 410b can be configured in the same manner as in the first embodiment, and the liquid 500 is supported by the water-repellent surface 410b without leaking out. As described with reference to FIG. 5(b), it is also desirable to provide the water-repellent surface 410b with a fine uneven shape so that the contact angle of the liquid 500 increases from the side closer to the area where the liquid 500 is held to the side farther away.

[0046] In this way, the outer cylinder 420a of the motor 420 and the heat transfer cylindrical member 410 can be in contact with each other over a wide area via the liquid 500, and heat generated by the motor 420 can be efficiently transferred to the heat transfer cylindrical member 410. Furthermore, by transferring heat via the liquid 500, an increase in the drive load can be suppressed compared to a configuration in which a solid heat conductive member is pressed against the outer cylinder 420.

[0047] The disclosure of this embodiment includes the following configurations and methods. (Configuration 1) An electronic device comprising: a device main body; a heating element arranged movably relative to the device main body; a water-repellent portion arranged to surround a partial area of ​​a space formed between the device main body and the heating element; and a liquid held in the area and transferring heat from the heating element to the device main body, wherein the water-repellent portion is arranged on at least one of the surfaces forming the space between the device main body and the heating element without contacting the other surface. (Configuration 2) The electronic device described in configuration 1, characterized in that at least one of the surfaces forming the space between the device body and the heating element has a convex portion protruding toward the other surface, and the water-repellent portion is provided on an upper surface of the convex portion or a surface facing the convex portion. (Configuration 3) The electronic device according to configuration 1 or 2, wherein the water-repellent portion is surrounded and sealed by a sealing member formed of a flexible material and disposed in the space. (Configuration 4) An electronic device described in any one of configurations 1 to 3, characterized in that the heating element has an imaging element, and the water-repellent portion is formed in a circular ring shape when viewed from a direction perpendicular to the imaging surface of the imaging element. (Configuration 5) The electronic device according to configuration 4, wherein the water-repellent portion is formed so that the contact angle of the liquid increases from the inner circumference side to the outer circumference side in the radial direction. (Configuration 6) The electronic device described in Configuration 1, characterized in that the heating element is a motor with a rotating outer cylinder, the device body has a tubular member surrounding the outer cylinder, and the water-repellent portion is provided in an annular shape at two locations on the inner surface of the tubular member at a predetermined interval in the direction of the rotational axis of the motor. (Configuration 7) The electronic device described in configuration 6, wherein the water-repellent portion is provided on the upper surface of a circular convex portion provided on the inner surface of the tubular member or on a surface facing the convex portion. (Configuration 8) The electronic device described in configuration 7, wherein the water-repellent portion is formed so that the contact angle of the liquid increases from the side closer to the area where the liquid is held to the side farther away. (Configuration 9) The electronic device according to any one of configurations 1 to 8, wherein the surface of the water-repellent portion has a fine uneven shape. (Configuration 10) An electronic device comprising a fixed part and a movable part arranged to be movable with a predetermined space relative to the fixed part, the movable part having a heating element, and a water-repellent part that holds a liquid that transfers heat from the movable part to the fixed part, the water-repellent part being provided on at least one of the surfaces that form the space between the fixed part and the movable part without contacting the other surface.

[0048] Although the present invention has been described in detail above based on the preferred embodiments, the present invention is not limited to these specific embodiments, and various forms within the scope of the gist of the present invention are also included in the present invention. Furthermore, each of the above-mentioned embodiments merely shows one embodiment of the present invention, and each embodiment can be appropriately combined.

[0049] For example, in the above-described first embodiment, the water-repellent surface 203b and the water-repellent surface 80a are formed by performing laser micromachining on the holding member 203 and the heat sink 80, respectively. However, without being limited to this, such water-repellent surfaces may be formed by using a method such as a silicon-based or fluorine-based coating process or grease application.

[0050] In addition, just as in the first embodiment, a water-repellent surface (water-repellent portion) is provided on both of the two surfaces that face each other with a small gap therebetween, in the second embodiment, a water-repellent surface may be provided on both the inner peripheral surface of the heat transfer cylindrical member 410 and the outer peripheral surface of the outer cylinder 420a, and they may be made to face each other. Also, if the water-repellent performance of the water-repellent surface is sufficient, in the first embodiment, as in the second embodiment, a water-repellent portion may be provided on at least one of the surfaces that form the space that holds the liquid so as not to come into contact with the other surface. In the above embodiment, a convex portion is provided to form a water-repellent surface on the upper surface of the convex portion, but it is not necessarily required to provide a convex portion. [Explanation of symbols]

[0051] 50 Image sensor 80 Heat sink 80a, 203b, 410b Water-repellent surface 100 Imaging device 203 Image sensor holding member 203a,410a Convex shaped part 300,500 liquid 310 Sealing member 410 Heat transfer cylinder parts 420 Motor

Claims

1. A device body, A heating element arranged movably relative to the device body; a water-repellent portion provided so as to surround a portion of a space formed between the device body and the heating element; a liquid that is held in the region and transfers heat from the heating element to the device body; The electronic device, characterized in that the water-repellent portion is provided on at least one of the surfaces that form the space between the device body and the heating element without contacting the other surface.

2. a convex portion is provided on at least one of the surfaces of the device body and the heating element that form the space, the convex portion protruding toward the other surface; The electronic device according to claim 1 , wherein the water repellent portion is provided on an upper surface of the convex portion or on a surface opposite to the convex portion.

3. 3. The electronic device according to claim 1, wherein the water-repellent portion is surrounded and sealed by a sealing member that is made of a flexible material and that is disposed in the space.

4. The heating element has an imaging element, 3. The electronic device according to claim 1, wherein the water-repellent portion is formed in a circular ring shape when viewed from a direction perpendicular to an imaging surface of the imaging element.

5. 5. The electronic device according to claim 4, wherein the water-repellent portion is formed so that a contact angle of the liquid increases from an inner periphery side to an outer periphery side in a radial direction.

6. The heating element is a motor that rotates an outer cylinder, The device body has a cylindrical member surrounding the outer cylinder, 2. The electronic device according to claim 1, wherein the water-repellent portion is provided in an annular shape at two positions on the inner circumferential surface of the cylindrical member at a predetermined interval in the direction of the rotation axis of the motor.

7. 7. The electronic device according to claim 6, wherein the water-repellent portion is provided on an upper surface of a circular convex portion provided on the inner circumferential surface of the cylindrical member, or on a surface facing the convex portion.

8. 8. The electronic device according to claim 7, wherein the water-repellent portion is formed so that a contact angle of the liquid increases from a side closer to the area where the liquid is held to a side farther from the area.

9. 3. The electronic device according to claim 1, wherein the surface of the water-repellent portion has a fine uneven shape.

10. A fixed portion; A movable part is disposed movably with respect to the fixed part with a predetermined space therebetween, The movable part has a heating element, An electronic device characterized in that a water-repellent portion that holds a liquid that transfers heat from the movable portion to the fixed portion is provided on at least one of the surfaces that form the space in the fixed portion and the movable portion without contacting the other surface.

Images