JP2019219458A - Imaging device - Google Patents

Abstract

To provide an imaging device which exerts a high heat radiation effect while suppressing influences on a product size and external appearance quality.SOLUTION: An imaging device comprises: a first housing unit which holds an imaging element positioned on an optical axis and a circuit board with a high-heat-generating electronic element mounted thereon; and a second housing unit which is fixed to the first housing unit and covers an entire rear face of the first housing unit. The imaging element and the circuit board have thermal connection primarily to the first housing unit and the second housing unit respectively. The second housing unit has a holding section which holds a display unit and a heat radiation section which is positioned opposite to the electronic element through an opening on the rear face of the first housing unit. An air flow passage which enables external air to flow thereinto and is not communicated with insides of the first housing unit and the second housing unit is formed between the heat radiation section and the holding section.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an imaging device that exerts a high heat radiation effect and suppresses the influence on product size and appearance quality.

  2. Description of the Related Art In recent years, there has been an increasing need for higher performance and more functions of digital cameras. As a result, the number of pixels of an imager, the speed of driving and signal processing, and the speed of image processing have been increased. As a result, the load on these electronic elements increases, leading to an increase in the amount of heat generated.

  When such heat generation occurs, not only does the malfunction of the processing of the electronic element itself occur, but also a local temperature rise occurs in the external part near the heated electronic element, which leads to a decrease in product quality and a low-temperature burn. There is also a risk.

  At the same time as high performance and multi-functionality, there is a demand for digital cameras to be smaller and thinner. As a result of the miniaturization and thinning of the camera, there is a possibility that the electronic elements that generate heat may approach and heat each other. In particular, when heat is transmitted to the imager unit and the temperature of the imager and the imager circuit rises, dark current, noise in signal reading and the like increase, and image quality deteriorates. In addition, since the electronic element and the external part approach each other and the surface area contributing to heat radiation decreases due to the miniaturization and thinning, the temperature rises locally and the temperature of the entire external appearance increases.

  The present applicant has filed Patent Document 1 in order to solve these problems. In the invention disclosed in Patent Literature 1, a lens unit including an imaging optical system, a metal outer cover, a lens barrel unit that is provided to protrude from the outer cover, and at least a part of the lens unit is loosely inserted, An imager unit having an imager and an imager board, a metal base member to which the imager unit is fixed and for adjusting the tilt of the imager, a main board on which heat-generating electronic elements are mounted, and a battery chamber for accommodating a battery. In an image pickup apparatus having a first heat dissipating member made of metal and a second heat dissipating member having elasticity, the imager unit and the main board are arranged adjacent to each other in a direction substantially orthogonal to the optical axis, and The heat radiating member is disposed to face the main board, the second heat radiating member is sandwiched between the first heat radiating member and the electronic element, and the base member and the first heat radiating member It is configured to be thermally connected.

  However, even when the above-described invention is adopted, there may be a case where heat radiation is not sufficient. Therefore, an imaging device provided with a special mechanism for dissipating heat has been conventionally proposed.

  For example, the invention disclosed in Patent Literature 2 includes an image pickup device arranged inside an outer case, and a circuit board mounted inside the outer case and on which electronic components serving as heating elements are mounted. A heat-dissipating air flow passage is formed on at least one side of the outer housing and is not communicated with the inside of the outer housing. The heat generated in the mounted electronic components is transmitted through the flow path forming section to be released from the air flow path for heat radiation to the outside of the outer casing, and the inside of the outer case opposite to the air flow path for heat radiation is sandwiched. A first arrangement space and a second arrangement space in which the circuit board is arranged, and a first portion located on the first arrangement space side and a second arrangement space in the flow passage forming portion of the outer casing. And a second portion positioned on the side of the image forming apparatus, and the image pickup device is disposed in the first arrangement space to form a flow passage. The first portion has a configuration which is formed by material having lower thermal conductivity than the second portion of the.

  According to the present invention, heat is hardly transmitted to a portion of the outer casing held by a user at the time of photographing or the like, and the amount of heat transmitted to the outer casing is suppressed, and the outer casing is enlarged to improve heat radiation efficiency. It is not necessary to take the measures described above, and it is possible to improve the heat radiation efficiency while securing the miniaturization of the image pickup device. Further, when a component that is easily affected by heat is arranged in the first arrangement space, It is stated that the components that are easily affected by heat can be located away from the electronic components by the air flow passage, and the effect of heat on components that are easily affected by heat can be reduced.

  Further, according to the invention disclosed in Patent Document 3, in the digital camera 1 which is an image pickup apparatus to which the image pickup device 13 for receiving a subject image formed by the photographing optical system and generating image data is used, the external body is provided. A front cover 4 and a rear cover 5; a main control board 15 disposed inside the front and rear covers, on which control electronic components are mounted; and a liquid crystal display unit movably supported by a rear surface 5a of the rear cover 5. 22 and provided on the back surface 5a of the rear cover 5 and provided along the vertical (Y) direction in a normal photographing hold state, and the upper end is opened to the outside air through a predetermined gap e. Has a plurality of grooves 5c for heat radiation which are directly open to the outside air.

  According to the present invention, the rear portion 5a is covered with the liquid crystal display unit 22 by providing a plurality of vertically extending grooves 5c in the rear portion 5a facing the central region of the main control board 15 of the rear cover 5. Even in the housed state (FIGS. 1 and 5) where the monitor can be observed, heat is effectively released from the groove 5c of the back surface 5a, the temperature of the image sensor 13 and the main control board 15 rises, and the liquid crystal display unit It is said that the temperature rise of the fuel cell 22 can also be suppressed.

Japanese Patent No. 5952111 Japanese Patent No. 4264583 JP 2012-053352 A

  However, the conventional technique described above has the following problems. That is, in the invention disclosed in Patent Literature 2, it is necessary to lay out the heat-dissipating air flow passage near the electronic component serving as the heating element, which greatly affects the internal structure of the imaging device. Therefore, it is difficult to satisfy both the design flexibility and the heat radiation performance at the same time.

  Further, in the invention disclosed in Patent Document 3, since the groove for heat dissipation is provided in the rear cover of the imaging device, the appearance quality of the product is deteriorated. Furthermore, since the liquid crystal display unit is movable, it does not contribute to heat radiation from the rear cover.

  The present invention has been made in view of such a situation, and it is an object of the present invention to provide an imaging device that exerts a high heat radiation effect and suppresses the influence on product size and appearance quality.

  In order to achieve the above object, an imaging device embodying the present invention includes an imaging device positioned on an optical axis and a first housing unit that holds a circuit board on which a high heat-generating electronic element is mounted. A second housing unit fixed to the first housing unit and covering the entire back surface of the first housing unit. And the circuit board is mainly thermally connected to the second housing unit. The second housing unit includes a holding unit for holding a display device, and the first housing unit. A heat radiating portion facing the electronic element via an opening provided on a back surface, wherein the heat radiating portion allows external air to flow in between the holding portion and the first housing unit. And forming an air passage not communicating with the inside of the second housing unit. .

  Further, in the imaging device embodying the present invention, preferably, the imaging element and the circuit board are respectively fixed at positions facing each other in the optical axis direction, and the electronic element does not face the imaging element of the circuit board. The electronic device and the heat radiating portion are mounted on a surface, and are thermally connected to each other through a heat conducting member.

  Further, in the imaging device embodying the present invention, preferably, the heat radiating portion has a concave / convex portion that increases a surface area of a surface facing the holding portion, and the air flow path includes the concave / convex portion and the holding portion. And formed between them.

  According to the imaging device embodying the present invention, it is possible to provide an imaging device that exerts a high heat radiation effect and suppresses the influence on the product size and appearance quality.

1 is an external perspective view of an imaging device according to an embodiment of the present invention. FIG. 4 is an exploded perspective view for explaining a main configuration of the rear unit. FIG. 2 is a cross-sectional view in the left-right direction illustrating a main internal structure of the imaging device. It is a perspective view for explaining the heat radiation structure which a back unit has. FIG. 4 is a cross-sectional view for explaining an air flow path formed by unevenness of a heat radiation structure. It is a perspective view for explaining other embodiments of a heat dissipation structure.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings. The present invention is not limited by the embodiment.

  The perspective view shown in FIG. 1 shows the outer appearance of the back side of an imaging device 100 according to an embodiment of the present invention. The imaging device 100 has a substantially rectangular shape as shown in this figure, and has a main body case 110 that forms the subject side and the upper, lower, left, and right side surfaces, and a back unit 200 that covers the back surface of the main body case 110. .

  A mount 120 is provided on the front side of the main body case 110 on the subject side. The mount unit 120 has a bayonet structure, and an interchangeable lens (not shown) is detachable.

  In the following description, the optical axis direction of the interchangeable lens mounted on the mount unit 120 in this figure is defined as the front-back direction, and the side on which the mount unit 120 is provided is defined as the front. In addition, a side on which a release button 111 described later is provided in the drawing is defined as an upper side, and an opposite side is defined as a lower side. Further, a direction orthogonal to the front-rear direction and the up-down direction is defined as a left-right direction, and the right side when the imaging device 100 with the release button 111 placed upward is viewed from the back side is defined as a right side.

  On an upper surface of the main body case 110, a release button 111 for performing an AF operation and an imaging operation, a power button 112 for turning on / off the power of the imaging apparatus 100, a moving image shooting button 113 for starting / ending recording of a moving image, A command dial 114 is provided.

  The command dial 114 is composed of a rotatable dial switch. By rotating the command dial 114 by a user, predetermined parameters, a shooting mode, and the like can be changed.

  FIG. 2 is an exploded perspective view for explaining a main configuration of the rear unit 200. The rear unit 200 mainly includes an LCD case 210 and a rear cover 220.

  An LCD unit 211 and an operation button unit 212 are arranged inside the LCD case 210. The LCD case 210 is provided with a predetermined contact surface, and the LCD unit 211 and the operation button unit 212 are positioned using this.

  Further, a glass panel (not shown) is fixed to the LCD case 210 with an adhesive or the like. The LCD unit 211 and the operation button unit 212 are fixed to the LCD case 210 by being attached to the inner surface of the glass panel.

  Further, the LCD case 210 is provided with a slot 213 in a part thereof. The flexible printed circuit boards (not shown) of the LCD unit 211 and the operation button unit 212 are electrically connected to a predetermined circuit board inside the main body case 110 through the elongated holes 213.

  The operation button unit 212 includes a cross button, a dial, an OK button, a play button, and the like.

  The back cover 220 has a size to cover all the openings on the back of the main body case 110, and is fixed to the main body case 110 by screws (not shown). The back cover 220 is also fixed to the LCD case 210 with screws.

  The rear cover 220 has a similar long hole 221 at a position facing the long hole 213 provided in the LCD case 210, and a flexible printed circuit board (not shown) also passes through the inside of the main body case 110 through the long hole 221. Crawled around.

  A heat dissipation structure 222 having a predetermined shape is provided on a rear surface of the back cover 220. Through the heat dissipation structure 222, heat generated inside the imaging device 100 is efficiently released. The heat radiation structure 222 will be described later in detail.

  FIG. 3 is a horizontal cross-sectional view illustrating a main configuration of the imaging device 100 in the left-right direction. The generation of heat inside the imaging device 100 and the heat radiation will be described with reference to FIG.

  Inside the main body case 110 that forms the appearance of the imaging device 100, a mount unit 120, an imaging element unit 130, a main board 140, and a back unit 200 are provided in this order from the front. On the right side of the image sensor unit 130, a battery storage unit 150 for storing a battery (not shown) is provided.

  The image sensor unit 130 is fixed to the main body case 110 with screws, and has an image sensor (not shown) that photoelectrically converts incident light from a subject. This image sensor is arranged so that the optical axis of the interchangeable lens mounted on the mount unit 120 and the central axis thereof coincide.

  The main board 140 is provided behind the image sensor unit 130 so as to be substantially parallel to the image sensor unit 130, and is fixed to the main body case 110 with screws.

  The rear unit 200 includes the rear cover 220 and the LCD case 210 as described above. The rear unit 220 is provided at the rear of the main body case 110 so as to cover an opening provided at a location facing the rear surface of the main board 140. Is provided. The back cover 220 is fixed to the main body case 110 with screws.

  Various electronic elements are mounted on both mounting surfaces of the main board 140, and each performs a predetermined processing operation. As shown in the figure, the DSP 141 and the SDRAM 142 are mounted on the mounting surface on the rear side of the main board 140. The DSP 141 performs various image processing on the acquired image data. Further, the SDRAM 142 functions as a buffer for temporarily storing image data during image processing.

  These electronic elements have a particularly high heat generation property, and generate heat when subjected to high-load processing such as continuous shooting or RAW image development, and are likely to become high in temperature. Hereinafter, these elements are also collectively referred to as a high heat generating element 143. However, what is included in the high heat generating element 143 is not limited to the DSP 141 and the SDRAM 142, and is appropriately selected from various electronic elements mounted on the main substrate 140.

  Further, a heat conductive member 144 is provided on the surface of the high heat generating element 143. The heat conductive member 144 is made of heat conductive rubber, and is attached to the surface of the high heat generating element 143 with a heat conductive double-sided tape or the like.

  The thickness of the heat conductive member 144 in the optical axis direction is set slightly larger than the distance between the heat conductive member 144 and the rear cover 220 when the rear cover 220 is attached. Thus, when the back cover 220 is fixed to the main body case 110, the heat conductive member 144 is sandwiched between the high heat generating element 143 and the back cover 220 to cause elastic deformation, and to be securely adhered to each surface.

  Next, how the heat generated in the image sensor unit 130 is transferred will be described with reference to FIG. Arrows in the figure indicate a rough heat transfer path from a main heat source in the imaging device 100.

  The main heat sources in the imaging apparatus 100 of the present embodiment include the above-described high heat generating element 143, that is, the DSP 141 and the SDRAM 142. As described above, the high heat generating elements 143 are mounted on the rear surface side of the main board 140, and the heat conductive member 144 is attached to the element surface.

  When a load is applied to the imaging apparatus 100 due to a user performing high-speed continuous shooting or the like, the temperature of the DSP 141 and the SDRAM 142 becomes high. Then, the generated heat is transmitted via the heat conductive member 144 to the back cover 220 to which the heat conductive member 144 is pressed.

  Heat is also transmitted from the high heat generating elements 143 such as the DSP 141 and the SDRAM 142 to the mounted main board 140, and there is a possibility that the elements mounted around may be adversely affected. Therefore, by attaching a heat conductive member 144 to the surface of the high heat generating element 143 and thermally connecting the heat conductive member 144 to the rear cover 220, the amount of heat transmitted to the main board 140 can be significantly reduced. The rear cover 220 has an area that covers almost the entire rear surface of the imaging device 100, and thus has a sufficient heat capacity.

  The main heat source may include an image sensor in the image sensor unit 130 in addition to the DSP 141 and the SDRAM 142 described above. On the other hand, when miniaturization is considered as an important element of the imaging device 100, the imaging device unit 130 and the main substrate 140 tend to be arranged close to each other. As a result, the image pickup element, which is a main heat source, comes close to the high heat generating element 143, so that further measures for heat generation are important.

  Therefore, in the imaging apparatus 100 according to the embodiment of the present invention, the heat radiation path is separated by the heat generated by the high heat generating element 143 mounted on the main board 140 and the heat generated by the imaging element. That is, while the heat generated by the high heat generating element 143 on the main board 140 is released to the rear of the image capturing apparatus 100, the heat generated by the image capturing element is transmitted to the image capturing unit 130 via the image capturing unit 130. The heat is diffused and dissipated by escaping to the front of the fixed main body case 110.

  Returning to the description of the heat radiation of the high heat generating element mounted on the main board 140. As shown in FIG. 2, a heat dissipation structure 222 having a predetermined shape is provided on the rear surface of the back cover 220. FIG. 4 is a perspective view of the back cover 220 alone for explaining the heat dissipation structure 222. FIG.

  In the present embodiment, the back cover 220 is provided with a heat radiation structure 222 so as to cover almost the entire rear surface as shown in FIG. In addition to the elongated holes 221 described above, abutment surfaces for defining the distance between the back cover 220 and the LCD case 210 at a predetermined distance are provided.

  The heat radiation structure 222 of the present embodiment has a structure in which a plurality of fins extending in parallel with the vertical direction of the imaging device 100 are arranged at predetermined intervals. With such a concavo-convex structure, the surface area of the rear surface of the back cover 220 is enlarged, and the heat flowing from the high heat generating element 143 can be efficiently diffused and dissipated.

  Further, according to this figure, the fins of the heat radiation structure 222 are provided up to the upper and lower ends of the back cover 220. Therefore, when the imaging device 100 is viewed from above or below, it looks as if a plurality of openings due to a large number of irregularities of the heat dissipation structure 222 are formed between the back cover 220 of the back unit 200 and the LCD case 210.

  FIG. 5 is a longitudinal sectional view of the upper opening 223 and the lower opening 224 formed by the unevenness of the heat radiation structure 222. As shown in the figure, an air flow path 225 is formed between the unevenness of the heat radiation structure 222 and the LCD case 210. The air flow path 225 penetrates from the lower surface opening 224 to the upper surface opening 223 of the imaging device 100, so that outside air can freely enter and exit.

  Inside each air passage 225, a flow of air is generated by a so-called chimney effect. That is, when the heat flowing from the high heat generating element 143 that has generated heat is transmitted to the heat radiation structure 222, the heat is transmitted to the air in the air flow path 225. The air heated by the heat rises in the air flow path 225 and escapes from the upper surface opening 223 of the imaging device 100 to the outside. Accordingly, outside air is drawn into the air passage 225 from the lower surface opening 224, and the inflowing outside air is heated again by the heat of the heat radiation structure 222.

  Therefore, the flow of air in the upward direction continues to be generated in the air flow path 225, and the heat radiation of the heat radiation structure 222 is continuously performed.

  The flow of air due to the chimney effect can be generated more efficiently by moving the position of the high heating element 143 mounted on the main board 140 to the bottom side below the imaging device 100.

  As described above, the heat from the high heat generating element 143 is radiated to the outside by the heat radiating structure 222 provided between the main body case 110 and the LCD case 210, so that the internal structure such as the arrangement of the high heat generating element 143 is improved. The heat radiation structure 222 can be made large without being affected by the heat radiation, and a high heat radiation effect can be obtained.

  In addition, since the heat radiation structure 222 is not exposed to the outside, the deterioration of the appearance quality as a product can be suppressed.

  Furthermore, since the heat radiation structure 222 is formed as the air flow paths 225 penetrating the openings provided on the upper and lower surfaces of the imaging device 100, an upward airflow is generated in each air flow path 225 by a chimney effect, so that the heat radiation efficiency is further improved. Can be increased.

  As described above, according to the imaging device embodying the present invention, it is possible to provide an imaging device that exerts a high heat radiation effect and suppresses the influence on the product size and appearance quality.

  In the above-described embodiment, the fin shape is adopted as the unevenness of the heat dissipation structure, but the present invention is not limited to this. For example, as shown in FIG. 6, even if a large number of boss shapes are employed as the unevenness, the surface area can be increased.

  In this case, since the direction of the air flow path is formed not only in the vertical direction but also in the horizontal direction, the degree of the chimney effect is reduced. However, even when the imaging device is used in a so-called vertical position, heat dissipation using the chimney effect is performed. Becomes possible.

100 imaging devices,
110 Body Case 111 Release Button 112 Power Button 113 Video Shooting Button 114 Command Dial 120 Mount Unit 130 Image Sensor Unit 140 Main Board 141 DSP
142 SDRAM
143 High heat generation element 144 Heat conduction member 150 Battery storage unit 200 Back unit 210 LCD case 211 LCD unit 212 Operation button unit 213 Slot 220 Back cover 221 Slot 222 Heat dissipation structure 223 Top opening 224 Lower opening 225 Air flow path

Claims (3)

A first housing unit that holds an imaging element positioned on the optical axis and a circuit board on which a high heat-generating electronic element is mounted;
A second housing unit fixed to the first housing unit and covering the entire back surface of the first housing unit.
The imaging element is mainly thermally connected to the first housing unit, the circuit board is mainly thermally connected to the second housing unit,
The second housing unit includes a holding unit that holds a display device, and a heat radiating unit that faces the electronic element via an opening provided on a back surface of the first housing unit,
The heat radiating portion is configured to form an air flow path through which outside air can flow in between the holding portion and the inside of the first housing unit and the second housing unit. Imaging device. The image sensor and the circuit board are fixed at positions facing each other in the optical axis direction,
The electronic element is mounted on a surface of the circuit board that does not face the imaging element,
The imaging device according to claim 1, wherein the electronic element and the heat radiating unit are thermally connected via a heat conductive member. The heat dissipating portion has an uneven portion that increases a surface area of a surface facing the holding portion,
The imaging device according to claim 1, wherein the air flow path is formed between the uneven portion and the holding portion.

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