JP2010193308A - Image capturing unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image capturing unit that dissipates heat on the side of a displaceable image sensor efficiently with no change over time, and can obtain an image by stable imaging signals at low cost. <P>SOLUTION: The image capturing unit 25 includes the image sensor 24 arranged on the optical axis O of a photographic lens 11 and on which the subject image is formed, an image sensor supporting plate 31 having heat dissipation properties and mounting the image sensor 24 on the surface thereof, a fixed heat sink 58 having heat dissipation properties and arranged fixedly to face the back surface of the supporting plate 31, a drive mechanism 60 which moves and displaces the supporting plate 31 relative to the fixed heat sink 58 in the two-dimensional direction which intersects the optical axis O orthogonally, a heat dissipation grease 71 which is applied to the fixed heat sink 58 and arranged in contact with the supporting plate 31, and a high viscosity grease 72 for preventing leakage of grease, which is applied to the fixed heat sink 58 in a state surrounding the area coated with the heat dissipation grease 71 and arranged in contact with the supporting plate 31. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an imaging unit including an imaging element that can be displaced in a two-dimensional direction orthogonal to the optical axis of a photographing lens.

  An electronic camera equipped with an imaging device such as a CCD receives subject light flux that has passed through a photographic lens with an imaging device, and obtains subject image data based on the photoelectric conversion output. Here, the image sensor itself generates heat during operation, and a dark current is generated by the heat, which may cause noise and reduce image quality. Therefore, heat dissipation measures are required, and various heat dissipation measures have been taken conventionally.

  On the other hand, recent electronic cameras include an image blur correction drive mechanism that moves the image sensor in a two-dimensional direction orthogonal to the optical axis, and for image blur correction so as to correct image blur when image blur is detected. Some have a camera shake correction function in which the image pickup device is displaced by a drive mechanism. In this case, the heat radiating member for radiating heat of the image pickup device cannot be directly attached to the movable part, and some device is required for heat radiation countermeasures.

  The sensor mounting system for an image pickup apparatus disclosed in Patent Document 1 realizes image stabilization that effectively removes heat from an optical sensor that is a movable image pickup element in a system that realizes image stabilization. As shown in the exploded perspective view of FIG. 18 and the sectional view of FIG. 19, this conventional sensor mounting system 402 includes a movable sensor mounting plate 505 including an electronic array type optical sensor 401, and fixed plates 501 and 503 having thermal mass. And at least one gap between the sensor mounting plate 505 and the fixed plates 501 and 503, and a ferrofluid 601 disposed in the at least one gap. The heat generated by the electronic array type optical sensor 401 is transferred to the fixing plates 501 and 503 side, and the temperature rise of the optical sensor 401 is suppressed.

  In the sensor mounting system 402, the fixing plates 501 and 503 are sufficiently separated as shown in FIG. 18, and therefore the circuit carrier sensor mounting portion 505 and the coil are disposed between the magnets attached to the fixing plates 501 and 503. 506 to 509 can move freely. Sufficient movement is made to allow the circuit carrier to move sufficiently in the X and Y directions and can compensate for most common camera shake signals. A preferable amount of movement of the sensor is +/− 1 to 2 mm in each axis.

  Gaps are provided on both sides of the movable part between the circuit carrier sensor mounting portion 505 and the magnet 502 and between the coils 506 to 509 and the magnet on the fixed plate 503. These gaps are substantially filled with ferrofluid 601. The ferrofluid 601 is obtained by suspending magnetic particles in a fluid and reacts to a magnetic field acting on the fluid. The ferrofluid 601 is strongly attracted to the maximum magnetic flux region between the magnets. This attractive force, together with the capillary action, keeps the ferrofluid 601 in the gap and relatively strongly holds the circuit carrier sensor mounting portion 505 and the coils 506 to 509 at the equilibrium position between the magnets. Movement in the X and Y axes (ie, directions parallel to the X and Y axes) is essentially free from static friction and only moderately hindered by dynamic friction due to the moderate viscosity of the ferrofluid. Thus, the ferrofluid 601 forms a fluid bearing that allows the sensor 401 to move freely in the desired direction for camera shake compensation and constrains the movement of the sensor 401 in other directions.

  In the sensor mounting system 402, the magnets 502 are composed of two pairs of four pairs, one pair being arranged above and below the fixing plate 501 in the Y direction, and the other pair being on the left and right in the X direction of the fixing plate 501. It is arranged.

  However, according to the sensor mounting system 402 disclosed in Patent Document 1, it is necessary to increase the heat transfer area in order to increase the temperature difference, that is, to increase the heat dissipation amount. In order to increase the heat transfer area, it is necessary to use a large amount of the ferrofluid 601. The ferrofluid 601 is expensive and has a cost problem. Further, as described above, the ferrofluid 601 is arranged in the gap between the circuit carrier sensor mounting portion 505 and the magnet 502 and between the coils 506 to 509 and the magnet on the fixed plate 503. Its surroundings are open. In particular, since the diagonal region of the sensor 401 is not generated as described above, there is a possibility that the ferrofluid 601 flows out in the region, and sufficient heat transfer cannot be maintained.

  The present invention has been made in view of the above, and can efficiently dissipate heat on the imaging element side that can be displaced in a two-dimensional direction orthogonal to the optical axis of the photographing lens without changing over time. It is another object of the present invention to provide an imaging unit that can obtain an image based on a stable imaging signal at low cost.

  In order to solve the above-described problems and achieve the object, the imaging unit according to the present invention is arranged on the optical axis of the photographing lens so as to be orthogonal to the optical axis, and an object image is formed by the photographing lens. An imaging element, a heat-radiating support plate on which the image-capturing element is mounted on the surface, a heat-dissipating fixing member fixedly disposed opposite to the back surface of the support plate, and the support plate A drive mechanism that displaces and moves in a two-dimensional direction perpendicular to the optical axis, a heat dissipating grease that is applied to the fixing member and is in contact with the support plate, and a region where the heat dissipating grease is applied. And a heat-dissipating grease outflow prevention material that is applied to the fixing member while being in contact with the support plate.

  According to the present invention, it is possible to efficiently dissipate heat on the imaging element side that can be displaced in a two-dimensional direction orthogonal to the optical axis of the photographing lens in a state that does not change with time, and is low in cost and stable. It is possible to provide an imaging unit that can obtain an image based on the captured imaging signal.

1 is a longitudinal sectional view taken along an optical axis of a photographic lens showing an outline of an internal structure of an eye reflex digital camera, which is an imaging device incorporating an imaging unit according to a first embodiment of the present invention. It is II-II sectional drawing of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2. FIG. 4A is a cross-sectional view along the optical axis of the thermal bonding portion between the imaging element support plate and the fixed heat dissipation plate in the imaging unit of the digital camera in FIG. 1, and FIG. 4A illustrates the imaging element support plate in a neutral position. FIG. 4B shows a state in which the imaging element support plate has moved in the Y direction. FIG. 5A is an enlarged view of a main part of the cross-sectional view of FIG. 4, FIG. 5A corresponds to FIG. 4A, and FIG. 5B corresponds to FIG. FIG. 5 is a perspective view illustrating a state in which thermal grease is applied to a fixed heat radiating plate and a state in which the fixed heat radiating plate is brought into contact with an image sensor side support plate in the imaging unit of FIG. FIG. 7A is a diagram showing the temperature gradient between the imaging element and the fixed heat sink in the present embodiment of FIG. 4 in comparison with the temperature gradient between the imaging element and the fixed heat sink in the conventional imaging device, and FIG. FIG. 7B shows the temperature gradient between the image sensor and the fixed heat sink in the conventional image pickup apparatus, and FIG. 7B shows the temperature gradient between the image sensor and the fixed heat sink in FIG. FIG. 8A is a cross-sectional view taken along the optical axis of the thermal joint portion between the imaging element support plate and the fixed heat dissipation plate in the imaging unit of the second embodiment of the present invention, and FIG. FIG. 8B shows a state where the image sensor support plate has moved in the Y direction. FIG. 9A is an enlarged view of a main part of the cross-sectional view of FIG. 8, FIG. 9A corresponds to FIG. 8A, and FIG. 9B corresponds to FIG. It is a perspective view which shows the state which contacted the said fixed heat sink to the support plate by the side of an image pick-up device from the state which apply | coats heat radiation grease etc. to a fixed heat sink in the imaging unit of FIG. FIG. 11A is a cross-sectional view taken along the optical axis of a thermal bonding portion between an imaging element support plate and a fixed heat radiating plate according to a modification of the imaging unit in FIG. 8, and FIG. 11A illustrates the imaging element support plate in a neutral position. A certain state is shown, and FIG. 11B shows a state in which the imaging element support plate is moved in the Y direction. FIG. 12A is a cross-sectional view taken along the optical axis of a thermal bonding portion between an imaging element support plate and a fixed heat sink in an imaging unit of a digital camera according to a third embodiment of the present invention, and FIG. FIG. 12B shows a state in which the support plate is in the neutral position, and FIG. 12B shows a state in which the image sensor support plate has moved in the Y direction. It is a perspective view which shows the state which contacted the said fixed heat sink to the image pick-up element support plate from the state which apply | coats heat radiation grease etc. to a fixed heat sink in the imaging unit of FIG. FIG. 14A is an enlarged cross-sectional view of the main part along the optical axis of the heat-bonded portion of the image pickup element support plate and the fixed heat sink in the modification to the image pickup unit of FIG. 12, and FIG. FIG. 14B shows a state where the image sensor support plate has moved in the Y direction. FIG. 15A is a cross-sectional view taken along the optical axis of a thermal joint portion between an imaging element support plate and a fixed heat sink in an imaging unit of a digital camera according to a fourth embodiment of the present invention, and FIG. FIG. 15B shows a state in which the support plate is moved in the Y direction. FIG. 16A is an enlarged view of a main part of the cross-sectional view of FIG. 15, FIG. 16A corresponds to FIG. 15A, and FIG. 16B corresponds to FIG. The FIG. 16 is a perspective view illustrating a state in which the fixed heat sink is brought into contact with the imaging element support plate from a state in which heat-release grease or the like is applied to the fixed heat sink built in the digital camera of FIG. 15. It is a disassembled perspective view of the imaging unit in the conventional imaging device. It is sectional drawing along an optical axis in the imaging unit of FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out an imaging unit and an imaging apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 is a photographic lens showing an outline of the internal structure of a camera body of a single-lens reflex digital camera (hereinafter referred to as a camera), which is an imaging apparatus incorporating an imaging unit as a first embodiment of the present invention. It is a longitudinal cross-sectional view along an optical axis. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG.

  The camera 1 according to the present embodiment includes a camera body 10 that forms a camera body appearance portion, and a photographing lens 11 that is mounted on the front side of the camera body 10 so as to be replaceable. The camera body 10 made of resin that constitutes the external shape of the camera 1 has a ring shape for mounting the lens unit 12 containing the photographing lens 11 in a replaceable manner at a front side position on the optical axis O of the photographing lens 11. A mount unit 13 is provided. Further, the camera body 10 has a grip portion 14 held by the operator's right hand on the left side when viewed from the front side during photographing or the like. Various switches such as a release switch and buttons are provided on the top of the grip portion 14.

  In the following description, the optical axis of the photographic lens 11 is indicated by the optical axis O in the state where it is mounted on the camera body 10, the subject side direction of the optical axis O is the front of the camera body 10, and the imaging side is the rear. And Of the directions along the plane perpendicular to the optical axis O, the left-right direction is the X direction, and the up-down direction perpendicular to the X direction is the Y direction.

  As shown in FIGS. 1 and 3, the camera body 10 includes a liquid crystal monitor 17 as a display device having an acrylic panel display window 16 at a position on the optical axis O on the back side. The liquid crystal monitor 17 is a TFT (Thin Film Transistor) type rectangular display panel that displays various information such as various settings and adjustment items in addition to the photographed image. The camera body 10 is provided with a finder window 18 through which an operator peeks at the time of shooting, and a hot shoe 19 to which an external flash is attached at the top.

  Further, as shown in FIG. 1, the camera body 10 incorporates a mirror member such as a quick return mirror 20 disposed on the optical axis O on the front side, and an AF sensor unit 21 that detects the amount of the defocus under the built-in mirror member. And a mirror box 22 containing the like. In the camera body 10, a focal plane shutter 23 and an imaging unit 25 including an imaging element 24 and the like are sequentially arranged on the optical axis O toward the back side of the quick return mirror 20. . In the camera body 10, a sub mirror 20 a is disposed behind the quick return mirror 20 on the optical axis O, and an optical path is set so that reflected light from the sub mirror 20 a is guided to the AF sensor unit 21. On the other hand, on the reflection side of the quick return mirror 20, a roof mirror 26, an eyepiece lens 27, and the like are arranged.

  A battery storage chamber 41 for storing a battery 40 is provided inside the grip portion 14 of the camera body 10. The battery 40 can be inserted into and removed from the battery storage chamber 41 by opening and closing an open / close lid 42 on the bottom surface. In addition, a circuit board 43 on which a circuit for controlling the entire camera, image processing, compression processing, data storage processing, a memory such as SDRAM, a power supply circuit, and the like are mounted on the back side inside the grip portion 14. , 44 are arranged. Flexible circuit boards 45 and 46 are electrically connected between the circuit board 43 and the image sensor support plate 31 on which the image sensor 24 is mounted, and between the circuit boards 43 and 44. In the grip portion 14, a memory slot 48 for loading a memory card 47 is formed between the battery storage chamber 41 and the circuit board 44, and is normally closed with a cover 49 that can be opened and closed. In the grip portion 14, a strobe aluminum electrolytic capacitor 50 is built in front of the battery storage chamber 41.

  The imaging unit 25 is disposed behind the focal plane shutter 23, and includes an optical LPF (low-pass filter) 30, an imaging element 24, an imaging element support plate 31 that is a support plate, a first holding member 51, and a second holding member. It comprises a member 52, a fixed frame 53 provided with a fixed heat sink 58, and a drive mechanism 60.

  The image sensor 24 photoelectrically converts a subject image formed on the imaging surface by the photographing lens 11 and has a horizontally long rectangular shape with a predetermined ratio. For example, a CCD image sensor is used in the camera 10 of the present embodiment. It has been. The image sensor 24 is not limited to a CCD image sensor, and may be a CMOS image sensor or the like.

  The imaging element support plate 31 is for mounting and fixing and positioning the imaging element 24 on the surface. The support plate 31 is made of a heat radiating material such as a metal having good heat radiating properties, and is made of an aluminum plate in the camera 1 of the present embodiment, and is formed in a horizontally elongated substantially rectangular shape larger than the image sensor 24.

  The first holding member 51 of the imaging unit 25 is for holding the imaging element support plate 31 and the optical LPF 30 that are formed in a rectangular frame shape and on which the imaging element 24 is mounted. The second holding member 52 is formed in a rectangular frame shape larger than the first holding member 51, and holds the first holding member 51 so as to be movable in the Y direction.

  Here, between the first holding member 51 and the second holding member 52, two steel balls 54 a are arranged so as to be movable only in the Y direction on one side in the X direction, and one on the other side. The first holding member 51 is supported so as to be smoothly movable in the Y direction with respect to the second holding member 52. A spring 55 is interposed between the first holding member 51 and the second holding member 52 in the vicinity of the steel ball 54b.

  The fixed frame 53 is formed in a rectangular frame shape that is slightly larger than the second holding member 52, and holds the second holding member 52 so as to be movable in the X direction. Here, between the second holding member 52 and the fixed frame 53, two steel balls 56a are arranged so as to be movable only in the X direction on the minus side in the Y direction, and one steel on the other side. The second holding member 52 can be smoothly moved in the X direction with respect to the fixed frame 53 by interposing the sphere 56b. A spring 57 is interposed between the second holding member 52 and the fixed frame 53 in the vicinity of the steel ball 56b. Further, the fixed frame 53 is assembled so that the image pickup device 24 is positioned on the optical axis O, for example, at four positions on a fixed portion such as the mirror box 22.

  In the fixed frame 53, a fixed heat radiating plate 58, which is a fixing member formed larger than the image pickup element support plate 31, is integrated with screws at a position close to and opposed to the back surface of the image pickup element support plate 31. That is, the fixed heat sink 58 also constitutes a part of the fixed frame. Further, the fixed frame 53 and the fixed heat dissipation plate 58 are made of a metal such as a metal having good heat dissipation, and for example, an aluminum plate or a PC resin (filler such as carbon fiber as a material having high thermal conductivity) ( Polycarbonate resin) or PPS resin (polyphenylene sulfide resin).

  A shield plate 96 is disposed on the back surface of the fixed heat radiating plate 58 with a heat conductive sheet 98 having high heat conductivity such as a graphite sheet interposed. Further, a liquid crystal monitor 17 is disposed on the back side of the shield plate 96 (FIGS. 1 and 3).

  There is a predetermined slight gap between the imaging element support plate 31 that supports the imaging element 24 and the fixed heat dissipation plate 58 on the fixed frame 53 side, and heat radiation grease 71 is applied in a state of filling the gap. A high-viscosity grease 72 that is a heat-dissipating grease flow-off preventing member is applied along the outer periphery of the heat-dissipating grease 71. The heat-dissipating grease 71 and the high-viscosity grease 72 will be described later with reference to FIGS.

  The drive mechanism 60 includes a first drive mechanism 61 and a second drive mechanism 62. The first drive mechanism 61 is provided between the first holding member 51 and the second holding member 52 so as to correspond to the steel ball 54 a portion, and the first holding member 51 is moved in the Y direction with respect to the second holding member 52. It is for moving the displacement. The first drive mechanism 61 is, for example, brought into press contact with the first holding member 51 and provided on the second holding member 52 side to generate elliptical vibration by applying a voltage to a drive electrode (not shown), whereby the first holding member A piezoelectric element drive motor type ultrasonic motor 61 using a piezoelectric element that moves 51 in the Y direction with respect to the second holding member 52 is configured.

The second drive mechanism 62 is provided between the second holding member 52 and the fixed frame 53 so as to correspond to the steel ball 56 a portion, and moves the second holding member 52 in the X direction relative to the fixed frame 53. belongs to. The second drive mechanism 62 also fixes the second holding member 52 by, for example, being brought into contact with the second holding member 52 and being provided on the fixed frame 53 side and generating an elliptical vibration by applying a voltage to a driving electrode (not shown). The drive mechanism 60 is not limited to the piezoelectric element drive motor system, and is configured by an electromagnetic drive system, which includes a piezoelectric element drive motor system ultrasonic motor 62 using a piezoelectric element that moves in the X direction with respect to the frame 53. A method of driving using a flexural vibration motor as a drive source or a method of driving using a VCM (voice coil motor) as a drive source may be used.

  By providing such a drive mechanism 60, the image pickup device support plate 31 on which the image pickup device 24 is mounted is displaced and moved in the two-dimensional directions in the vertical and horizontal directions within the XY plane orthogonal to the optical axis O with respect to the fixed frame 53. It becomes possible. Therefore, when camera shake is detected in the single-lens reflex digital camera during shooting in the camera shake correction mode, the drive mechanism 60 is driven to cause the image sensor support plate 31 to move in the two-dimensional direction in the XY plane. By moving the displacement so as to be corrected, it is possible to correct image blurring on the light receiving surface of the image sensor 24.

  Here, in the image pickup unit 25, the heat radiating grease 71, the high-viscosity grease 72 disposed in the gap on the image pickup element support plate 31 side of the fixed heat radiating plate 58, and the fixed heat radiating plate 58 and the imaging with the grease interposed therebetween. The relative movement operation of the element support plate 31 will be described with reference to FIGS.

  FIG. 4 is a cross-sectional view along the optical axis of the thermal joint portion between the imaging element support plate and the fixed heat dissipation plate in the imaging unit, and FIG. 4A shows the imaging element support plate in a neutral position. FIG. 4B shows a state where the imaging element support plate has moved in the Y direction. 5 is an enlarged view of a main part of the cross-sectional view of FIG. 4. FIG. 5 (A) corresponds to FIG. 4 (A), and FIG. 5 (B) corresponds to FIG. Yes. FIG. 6 is a perspective view showing a state in which heat-dissipating grease is applied to the fixed heat radiating plate in the image pickup unit of FIG.

  The heat dissipating grease 71 is made of a paste-like material filled with a filler, for example, a silicon gel agent, in order to improve the thermal conductivity, and aluminum fiber, carbon fiber, graphite or the like is applied to the filler. The high-viscosity grease 72 is a grease that has a high viscosity and maintains its applied shape.

  The fixed heat radiating plate 58 is provided with a groove 58b along the outer periphery of the quadrangular region 58a corresponding to the outer shape of the image sensor 24.

  The method for applying the high-viscosity grease 72 and the heat-dissipating grease 71 to the fixed heat radiating plate 58 will be described. First, as shown in FIG. 6, the high-viscosity grease 72 is injected into the groove 58b of the fixed heat-radiating plate 58 and applied. . Subsequently, the heat radiating grease 71 is applied to the quadrilateral region 58 a of the fixed heat radiating plate 58 inside the high viscosity grease 72. The imaging element support plate 31 on which the imaging element 24 is mounted is assembled with the first holding member 51, the second holding member 52, and the fixed frame 53 interposed between the fixed heat radiating plate 58 to which the grease is applied.

  In the assembled state, the applied grease is in a state where the application front surface (upper surface in FIG. 6) is in close contact with the back surface (lower surface in FIG. 6) of the image sensor support plate 31.

  The image pickup device support plate 31 and the fixed heat dissipation plate 58 are attached via high-viscosity grease 72 and heat dissipation grease 71, and the center of the image pickup device support plate 31 (the center of the light receiving surface of the image pickup device 24) is the optical axis O. FIG. 4A and FIG. 5A show the state when the values coincide with each other. FIGS. 4B and 5B show a state when the image pickup device support plate 31 is moved in the Y direction with respect to the fixed heat radiating plate 58 by the shake correction operation, for example. In this state, the high-viscosity grease 72 is deformed, so that the image sensor support plate 31 is relatively moved. The high-viscosity grease 72 and the heat-dissipating grease 71 are kept in close contact with the image sensor support plate 31, and the high-viscosity grease 72 prevents the heat-dissipating grease 71 from flowing out of the quadrangular region 58 a. Note that when the image sensor support plate 31 moves relative to the direction other than the Y direction, the high-viscosity grease 72 is deformed following the image sensor support plate 31 in the same manner as in the state shown in FIG. The grease contact state is maintained and the outflow of the heat dissipating grease 71 is suppressed.

  As described above, in the imaging unit 25, the imaging element support plate 31 and the fixed heat radiating plate 58 are in contact with each other with the heat radiation grease 71 interposed therebetween in an imaging state including a blur correction operation and an imaging standby state. The heat generated in the image sensor 24 is efficiently transmitted to the fixed heat sink 58 via the image sensor support plate 31 and the heat radiation grease 71. The transferred heat is efficiently transferred from the fixed heat radiating plate 58 directly to the air in the camera body, from the fixed frame 53 to the mirror box 22, and further to the shield plate 96 through the heat conductive sheet 98. Heat is transferred to each. The heat transmitted to the shield plate 96 is radiated to the outside as it is, or is transmitted to the liquid crystal monitor 17 side, and further radiated to the outside via the air layer or the acrylic panel display window 16.

  FIG. 7 is a diagram showing a temperature gradient from the image sensor 24 to the fixed heat sink 58 in the image pickup unit 25 of the present embodiment as compared with the conventional image pickup unit 25Z, and FIG. FIG. 7B shows the case of the conventional imaging unit 25Z.

  As shown in FIG. 7B, in the case of the conventional imaging unit 25Z, an air layer Z exists between the imaging element support plate 31 and the fixed heat radiating plate 58Z. Therefore, the temperature difference between the image sensor support plate 31 and the fixed heat radiating plate 58Z is large, and the temperature ta of the image sensor 24 is high. On the other hand, in the case of the imaging unit 25 of the present embodiment, since the heat radiation grease 71 is disposed in close contact between the image sensor support plate 31 and the fixed heat radiation plate 58Z as described above, FIG. As shown, the temperature difference between the image sensor support plate 31 and the fixed heat radiating plate 58 is reduced, and the temperature tb of the image sensor 24 is significantly lower than the temperature ta. Therefore, the deterioration of the image signal due to the temperature rise of the image sensor 24 can be suppressed.

  Further, since the entire periphery of the heat dissipating grease 71 is surrounded by the high-viscosity grease 72, it is prevented that the heat dissipating grease 71 flows out to the outside even if there is a relative movement of the image sensor support plate 31 due to blur correction.

  As described above, according to the digital camera 1 of the present embodiment, the heat generated in the image sensor 24 by applying the above-described simple configuration is fixed and radiated from the image sensor support plate 31 via the heat radiation grease 71. It is possible to realize a digital camera that is efficiently transmitted to the plate 58, the temperature rise of the image sensor 24 is suppressed, and a stable image signal can be obtained.

  In addition, since the entire periphery of the applied heat radiation grease 71 is surrounded by the high viscosity grease 72, even if there is a state in which the image pickup device support plate 31 moves relative to the fixed heat radiation plate 58 by the shake correction operation, the heat radiation is performed. The grease 71 is prevented from flowing out and is reliably held in a predetermined region on the fixed heat radiating plate 58 in a state that does not change with time.

  Although the ultrasonic motors 61 and 62 using piezoelectric elements are applied as the actuator of the drive mechanism 60 applied in the present embodiment, a stepping motor can be applied instead. Furthermore, it is also possible to apply a moving coil type voice coil motor or a moving magnet type voice coil motor. In this case, the support plate 31 and the fixed heat radiating plate 58 need to be formed of a magnetic material.

  Next, an imaging unit according to the second embodiment of the present invention will be described with reference to FIGS.

  FIG. 8 is a cross-sectional view along the optical axis of the thermal joint portion between the imaging element support plate and the fixed heat dissipation plate in the imaging unit of the present embodiment, and FIG. 8A shows that the imaging element support plate is neutral. FIG. 8B shows a state where the image sensor support plate has moved in the Y direction. 9 is an enlarged view of the main part of the cross-sectional view of FIG. 8, FIG. 9 (A) corresponds to FIG. 8 (A), and FIG. 9 (B) corresponds to FIG. 8 (B). Yes. FIG. 10 is a perspective view showing a state in which the fixed heat radiating plate is brought into contact with a support plate on the image pickup element side from a state in which heat radiating grease or the like is applied to the fixed heat radiating plate in the image pickup unit of FIG.

  The digital camera in which the imaging unit 25A of this embodiment is built has the same configuration as that of the digital camera 1 of the first embodiment, and in the following description, the same components are denoted by the same reference numerals. Hereinafter, differences from the imaging unit 25 of the imaging unit 25A will be described.

  Also in the imaging unit 25A, as shown in FIG. 8, in the same manner as in the imaging unit 25, a predetermined portion is disposed between the imaging element support plate 31 that supports the imaging element 24 and the fixed heat dissipation plate 58 on the fixed frame 53 side. There is a slight gap, and the heat dissipating grease 71A is applied so as to fill the gap. And the gel sheet 72A which is a heat-radiation-grease loss prevention member is arrange | positioned along the outer periphery of the heat-radiation grease 71A.

  The heat dissipating grease 71A is made of a paste-like material, for example, a silicon gel agent, filled with a filler in order to improve the thermal conductivity in the same manner as the heat dissipating grease 71. The filler includes aluminum fiber, carbon fiber, or graphite. Etc. apply. The gel sheet 72A is made of a quadrilateral frame-like gel sheet material.

  The fixed heat radiating plate 58 is provided with a groove 58 b along the outer periphery of the quadrilateral region 58 a corresponding to the outer shape of the image sensor 24. Further, a groove 31a having a shape facing the groove 58b is also provided on the back surface portion (lower surface portion in FIG. 10) on the imaging element support plate 31 side.

  The method of disposing the gel sheet 72A on the fixed heat radiating plate 58 and applying the heat radiating grease 71A will be described. First, as shown in FIG. 10, the gel sheet 72A is fitted into the groove 58b. Subsequently, heat radiation grease 71A is applied to the quadrangular region 58a of the fixed heat radiation plate 58 inside the gel sheet 72A. The imaging element support plate 31 on which the imaging element 24 is mounted is assembled with the first holding member 51, the second holding member 52, and the fixed frame 53 interposed on the fixed heat dissipation plate 58 to which the heat dissipation grease 71 </ b> A is applied. At that time, the front surface portion (upper surface portion in FIG. 10) of the gel sheet 72 </ b> A is fitted into the groove 31 a of the imaging element support plate 31.

  In the assembled state described above, the applied heat-dissipating grease 71A and the gel sheet 72A are in a state in which their front surfaces (upper surface in FIG. 10) are in close contact with the rear surface (lower surface in FIG. 10) of the image sensor support plate 31.

  The imaging element support plate 31 and the fixed heat dissipation plate 58 are attached via a gel sheet 72A and heat dissipation grease 71A, and the center of the imaging element support plate 31 (the center of the light receiving surface of the imaging element 24) is aligned with the optical axis O. FIG. 8A and FIG. 9A show the state when doing so. FIG. 8B and FIG. 9B show a state when the image pickup device support plate 31 is moved in the Y direction, for example, with respect to the fixed heat radiating plate 58 by the shake correction operation. In this state, when the gel sheet 72A is deformed, the image sensor support plate 31 is relatively moved. Then, the heat-release grease 71A is kept in close contact with the image sensor support plate 31, and the gel sheet 72A prevents the heat-release grease 71 from flowing out. Note that the same state as that in the case of FIG. 9B can be obtained also when the imaging element support plate 31 is moved in a direction other than the Y direction.

  Accordingly, the heat generated in the image sensor 24 is efficiently transmitted from the image sensor support plate 31 to the fixed heat radiating plate 58 through the heat radiating grease 71A as in the case of the image pickup unit 25, and the heat radiating grease 71A flows out and disappears. Is also reliably prevented.

  The imaging unit 25A of the present embodiment also has the same effect as the imaging unit 25 incorporated in the digital camera 1 of the first embodiment, but in the present embodiment, the gel sheet 72A is applied instead of the high viscosity grease 72. Therefore, it is possible to more reliably prevent the heat radiation grease 71A from being held in the quadrilateral region 58a and flowing out to the outside.

  Next, as an imaging unit of a modification to the imaging unit 25A of the second embodiment, an imaging element support plate in which a flexible printed circuit board (hereinafter referred to as FPC) is disposed in close contact with the back surface is applied. This will be described with reference to FIG.

  FIG. 11 is a cross-sectional view along the optical axis of the heat-bonding portion of the image pickup device support plate and the fixed heat sink of the image pickup unit 25B of this modification, and FIG. 11A shows that the image pickup device support plate is neutral. FIG. 11B shows a state in which the imaging element support plate has moved in the Y direction.

  As shown in FIG. 11A, the imaging element support plate 31B applied to the imaging unit 25B of this modification has an FPC 73 attached in close contact with the back side, and the FPC 73 has a groove of the fixed heat radiating plate 58. A groove 73a is provided at a position facing 58b.

  The gel sheet 72B fitted in the groove 58b of the fixed heat radiating plate 58 in the assembled state of the imaging unit 25B is sandwiched between the fixed heat radiating plate 58 and the imaging element support plate 31B in a state fitted in the groove 73a of the FPC 73. The fixed heat radiating plate 58 and the imaging element support plate 31B hold the heat radiating grease 71 applied to the quadrangular region 58a inside the gel sheet 72B in a state of being in close contact via the FPC 73.

  The imaging unit 25B of this modification also has the same effect as the imaging unit 25A of the second embodiment. In particular, in this modification, an imaging element support plate 31B having an FPC disposed on the fixed heat sink 58 side can be applied. It is.

  Next, an imaging unit according to a third embodiment of the present invention will be described with reference to FIGS.

  FIG. 12 is a cross-sectional view along the optical axis of the thermal joint portion between the imaging element support plate and the fixed heat dissipation plate in the imaging unit of the present embodiment, and FIG. 12A shows that the imaging element support plate is neutral. FIG. 12B shows a state where the image sensor support plate has moved in the Y direction. FIG. 13 is a perspective view showing a state in which the fixed heat radiating plate is brought into contact with the support plate on the image sensor side from the state in which heat radiating grease or the like is applied to the fixed heat radiating plate in the image pickup unit of FIG.

  The digital camera in which the imaging unit 25C of this embodiment is built has the same configuration as that of the digital camera 1 of the first embodiment, and in the following description, the same components are denoted by the same reference numerals. Hereinafter, differences from the imaging unit 25 of the imaging unit 25C will be described.

  Also in the imaging unit 25C, as shown in FIG. 12, the imaging element support plate 31 that supports the imaging element 24 and the fixed heat radiating plate 58C that is a fixing member on the fixed frame 53 side are opposed to each other as in the imaging unit 25. Has a predetermined slight gap, and the heat radiation grease 71C is applied in a state of filling the gap. A magnetic fluid 72C is applied along the entire outer periphery of the heat dissipation grease 71C as a heat dissipation grease flow prevention member.

  The heat dissipating grease 71C is made of a paste-like material, for example, a silicon gel agent, filled with a filler in order to improve the thermal conductivity in the same manner as the heat dissipating grease 71. The filler includes aluminum fiber, carbon fiber, or graphite. Etc. apply. The magnetic fluid 72C is obtained by suspending magnetic particles in a fluid, reacts to a magnetic field, and is strongly attracted to a maximum magnetic flux region between magnets. In addition, the magnetic fluid 72C has a high viscosity and maintains the shape of the applied state.

  As shown in FIGS. 12 and 13, the fixed heat radiating plate 58 </ b> C is provided with a groove 58 </ b> Cb along the outer periphery of the quadrangular region 58 </ b> Ca corresponding to the outer shape of the imaging device 24, and the magnet 74 </ b> C polarized in the thickness direction is provided in the groove. Has been inserted.

  A method for applying the magnetic fluid 72C and the heat dissipation grease 71C to the fixed heat radiating plate 58C will be described with reference to FIG. 13. First, the magnetic fluid 72C is applied along the magnet 74C disposed in the groove 58Cb. Subsequently, heat radiation grease 71C is applied to the quadrilateral region 58Ca of the fixed heat radiation plate 58C inside the magnetic fluid 72C. The imaging element support plate 31 on which the imaging element 24 is mounted with the first holding member 51, the second holding member 52, and the fixed frame 53 interposed with respect to the fixed heat radiation plate 58C to which the magnetic fluid 72C and the heat radiation grease 71C are applied. Is assembled.

  The heat-dissipating grease 71C applied in the above-described assembled state and the magnetic fluid 72C surrounding the entire circumference of the heat-dissipating grease 71C are in close contact with the back surface (lower surface in FIG. 13) of the image sensor support plate 31. It becomes a state to do.

  The image pickup device support plate 31 and the fixed heat dissipation plate 58C are attached via a magnetic fluid 72C and heat dissipation grease 71C, and the center of the image pickup device support plate 31 (the center of the light receiving surface of the image pickup device 24) is shown in FIG. The state when) coincides with the optical axis O is shown. FIG. 12B shows a state when the imaging element support plate 31 is moved in the Y direction, for example, with respect to the fixed heat radiating plate 58C by the shake correction operation. In this state, the heat radiation grease 71C is kept in close contact with the image sensor support plate 31, and the magnetic fluid 72C is displaced with the support plate 31 while the fixed heat radiation plate 58C is attracted to the magnet 74C and the image sensor support plate 31 is displaced with the support plate 31. Thus, the image sensor support plate 31 is relatively moved. And since the whole periphery of the application | coating area | region of the thermal radiation grease 71C is surrounded by the magnetic fluid 72C, an outflow is suppressed reliably. Note that the same state as in the case of FIG. 12B is also obtained when the imaging element support plate 31 is moved in a direction other than the Y direction.

  Accordingly, the heat generated in the image sensor 24 is efficiently transmitted from the image sensor support plate 31 to the fixed heat radiating plate 58C via the heat radiating grease 71C as in the case of the image pickup unit 25, and the heat radiating grease 71C flows out and decreases. It is definitely prevented.

  The imaging unit 25C of the present embodiment also has the same effect as the imaging unit 25 incorporated in the digital camera 1 of the first embodiment. In particular, in the case of this embodiment, the magnetic fluid 72C is replaced with the high-viscosity grease 72. By applying and surrounding the entire circumference of the heat radiating grease 71C, the heat radiating grease 71C can be held in the quadrangular region 58Ca, and the outflow to the outside can be more reliably prevented. Furthermore, the magnetic fluid 72C can be prevented from being adsorbed by the magnet 74C and disappearing to the outside. Further, the magnetic fluid 72C only surrounds the entire circumference of the heat dissipating grease 71C, and its use amount is small, which is advantageous in terms of cost.

  Next, as an imaging unit as a modification of the imaging unit 25C of the third embodiment, an imaging device support plate on which magnets are arranged will be described with reference to FIG.

  FIG. 14 is a cross-sectional view taken along the optical axis of the heat-bonded portion of the image pickup device support plate and the fixed heat sink of the image pickup unit 25D of this modification, and FIG. 14A shows that the image pickup device support plate is neutral. FIG. 14B shows a state where the image sensor support plate has moved in the Y direction.

  As shown in FIG. 14A, the imaging element support plate 31D applied to the imaging unit 25D of this modification is provided with a groove 31Db facing the groove 58Cb of the fixed heat radiating plate 58C. A magnet 74D is inserted. The magnet 74D is a magnet that is polarized in the thickness direction as shown in FIG.

  In the imaging unit 25D of this modification, the fixed heat radiating plate 58C side is attracted to the magnet 74C while the magnetic fluid 72C surrounds the entire circumference of the heat radiating grease 71C, and the imaging element support plate 31D side is also attracted to the magnet 74D. Therefore, the heat dissipating grease 71C is held so as not to flow out by the magnetic fluid 72C, the disappearance of the magnetic fluid 72C can be more reliably prevented, and the secular change is also eliminated.

  Next, an imaging unit according to a fourth embodiment of the present invention will be described with reference to FIGS.

  FIG. 15 is a cross-sectional view taken along the optical axis of the thermal bonding portion between the imaging element support plate and the fixed heat dissipation plate in the imaging unit of the present embodiment, and FIG. 15A shows that the imaging element support plate is neutral. FIG. 15B shows a state where the image sensor support plate has moved in the Y direction. 16 is an enlarged cross-sectional view of the main part of FIG. 15, FIG. 16A corresponds to FIG. 15A, and FIG. 16B corresponds to FIG. 15B. FIG. 17 is a perspective view showing a state in which the fixed heat radiating plate is brought into contact with the support plate on the image sensor side from the state in which heat radiating grease or the like is applied to the fixed heat radiating plate in the image pickup unit of FIG.

  The digital camera in which the imaging unit 25E of this embodiment is built has the same configuration as that of the digital camera 1 of the first embodiment, and in the following description, the same components are denoted by the same reference numerals. Hereinafter, differences from the imaging unit 25 of the imaging unit 25E will be described.

  Also in the imaging unit 25E, as shown in FIG. 15, a predetermined slight gap is formed between the imaging element support plate 31 that supports the imaging element 24 and the fixed heat radiating plate 58E that is a fixing member on the fixed frame 53 side. Yes, the heat dissipating grease 71E is applied while filling the gap. A packing 72E as a heat dissipation grease loss prevention member is disposed so as to surround the outer periphery of the heat dissipation grease 71E.

  The heat dissipating grease 71E is made of a paste-like material, for example, a silicon gel agent, filled with a filler in order to improve the thermal conductivity in the same way as the heat dissipating grease 71. The filler includes aluminum fiber, carbon fiber, or graphite. Etc. apply.

  The packing 72E is made of a quadrangular frame-shaped rubber packing material that is inserted into a groove 58Eb of a fixed heat radiating plate 58E, which will be described later, and is provided with a concave groove 72Ea on the front surface side (the upper surface side in FIG. 17).

  The fixed heat radiating plate 58E is provided with a groove 58Eb along the outer periphery of the quadrangular region 58Ea corresponding to the outer shape of the imaging element 24.

  The method for fitting the packing 72E to the fixed heat radiating plate 58E and applying the heat radiating grease 71E will be described. First, as shown in FIG. The heat dissipating grease 71E is applied to the quadrangular region 58Ea of the plate 58E. The imaging element support plate 31 on which the imaging element 24 is mounted is assembled with the first holding member 51, the second holding member 52, and the fixed frame 53 interposed between the fixed heat radiating plate 58E to which the grease is applied.

  The heat-dissipating grease 71E applied in the above-described assembled state has its application front surface (upper surface in FIG. 17) closely attached to the rear surface (lower surface in FIG. 17) of the image sensor support plate 31, and both the concave grooves 72Ea of the packing 72E. The tip end part abuts on the back surface (lower surface in FIG. 17) of the image sensor support plate 31.

  The image pickup device support plate 31 and the fixed heat dissipation plate 58E are attached via a packing 72E and heat dissipation grease 71E, and the center of the image pickup device support plate 31 (the center of the light receiving surface of the image pickup device 24) coincides with the optical axis O. FIG. 15 (A) and FIG. FIG. 15B and FIG. 16B show a state when the image pickup device support plate 31 is moved in the Y direction, for example, with respect to the fixed heat radiating plate 58E by the shake correction operation. In this state, the contact state of the heat dissipating grease 71E with the image pickup device support plate 31 is maintained, and both end portions of the concave groove 72Ea of the packing 72E are in close contact with the image pickup device support plate 31 in a state where it is easy to slide. Therefore, the relative movement of the image sensor support plate 31 is not hindered, and the outflow of the heat-dissipating grease 71E to the outside of the quadrangular region 58Ea is also suppressed. Note that when the image pickup device support plate 31 moves relatively in a direction other than the Y direction, both end portions of the concave groove 72Ea of the packing 72E with respect to the image pickup device support plate 31 as in the state shown in FIG. Slip in the close contact state, and the outflow of the heat dissipating grease 71E is similarly suppressed.

  Accordingly, the heat generated in the image sensor 24 is efficiently transmitted from the image sensor support plate 31 to the fixed heat radiating plate 58E via the heat radiating grease 71E as in the case of the image pickup unit 25, and the heat radiating grease 71E flows out and decreases. It is definitely prevented.

  The imaging unit 25E of the present embodiment also achieves the same effect as the imaging unit 25 incorporated in the digital camera 1 of the first embodiment. In particular, in the case of the present embodiment, heat is released by applying the packing 72E surrounding the heat radiation grease 71E. The disappearance of the grease 71E can be reliably prevented, and the secular change is extremely reduced.

  As described above, the image pickup unit of the present invention can efficiently dissipate heat on the image pickup element side that can be displaced in a two-dimensional direction orthogonal to the optical axis of the photographing lens without changing with time, and is low in cost. Thus, it can be used as an imaging unit that can obtain an image based on a stable imaging signal.

DESCRIPTION OF SYMBOLS 11 ... Shooting lens 24 ... Image pick-up element 31, 31D ... Image pick-up element support plate (support plate)
58, 58C, 58E ... Fixed heat sink (fixing member)
60 ... Drive mechanism 71, 71A, 71C, 71E ... Heat dissipating grease 72 ... High viscosity grease (Heat dissipating grease material)
72A ... Gel sheet (heat dissipation grease loss prevention material)
72C ... Magnetic fluid (heat dissipation grease loss prevention material)
72E ... Packing (heat dissipation grease loss prevention material)

JP 2006-33856 A

Claims (4)

An image sensor that is arranged on the optical axis of the photographic lens so as to be orthogonal to the optical axis and forms a subject image by the photographic lens;
A heat-radiating support plate on which the image sensor is mounted;
A fixing member having heat dissipation disposed fixedly facing the back surface of the support plate;
A drive mechanism for moving the support plate in a two-dimensional direction perpendicular to the optical axis with respect to the fixed member;
Thermal grease applied to the fixing member and arranged in contact with the support plate;
A heat-dissipating grease outflow prevention material that is applied to the fixing member in a state of surrounding the application region of the heat-dissipating grease, and arranged in contact with the support plate;
An imaging unit comprising: The imaging unit according to claim 1, wherein the heat dissipating grease is a paste-like material filled with a filler. The imaging unit according to claim 2, wherein the filler filled in the paste-like material is one of aluminum fiber, carbon fiber, or graphite. The imaging unit according to claim 1, wherein the heat release grease outflow prevention material is one of a gel sheet, a high viscosity grease, a packing member, and a magnetic fluid.

Images