JP2006157254A - Imaging unit and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the heat of the heat dissipation side of a cooling element from returning to an imaging element resulting in involuntarily warming up the imaging element when the cooling element is not driven in the case that the cooling element is driven only at photographing to cool the imaging element for the reduction of power consumption. <P>SOLUTION: The imaging unit is provided with: a second heat dissipation member for dissipating the heat of the cooling element for cooling the imaging element; and a first heat dissipation member for dissipating the heat of the imaging element when the cooling element is not driven. A circuit board is inserted between the first and second heat dissipation members to thermally isolate both the heat dissipation members thereby preventing the returning of the heat. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an imaging unit and an imaging apparatus. In particular, the present invention relates to an imaging unit and an imaging apparatus that include a cooling element that cools the imaging element.

  In recent years, as the number of pixels in an imaging device such as a digital camera increases, the image quality increases, the frame rate increases, and the size decreases, the density of pixels in an imaging element such as a CCD has increased. Accordingly, there is a concern that the image quality may be adversely affected by the heat generated in the image sensor chip by driving the image sensor. In general, it is known that in an image pickup device such as a CCD, when the temperature of the image pickup device chip rises by 8 ° C., dark current, that is, dark noise doubles. Therefore, when imaging at a high frame rate is performed with a high-density imaging element chip, the S / N ratio of the image signal is reduced due to dark noise due to heat generation. For this reason, a method of reducing the dark current by cooling an image pickup device such as a CCD and improving the S / N ratio of the image signal is employed.

  For this reason, a structure using a Peltier element as a cooling structure for an image sensor such as a CCD is known (for example, see Patent Document 1). According to this, as a cooling structure of an image sensor such as a CCD, a CCD, a Peltier element, a heat transfer member, and a heat dissipation member are arranged in order and pressed against each other by a leaf spring, and heat from the CCD is absorbed by the Peltier element. At the same time, the heat is transferred from the Peltier element to the camera casing through the heat transfer member and the heat dissipation member by heat conduction, and is radiated to the outside.

  On the other hand, there has been proposed one that improves the cooling effect of the Peltier element by intermittently driving the Peltier element with a pulse current (see, for example, Patent Document 2). According to this, when the Peltier element is driven with a pulse current, the imaging element is cooled, and at this time, the heat generated on the heat generation side of the Peltier element is released to the outside by the radiation fin when the Peltier element is not driven, It is said that the cooling effect of the Peltier element can be prevented from being reduced by the temperature rise of the heat generating part of the Peltier element and the cooling effect can be improved.

Furthermore, when a cooling element such as a Peltier element is used in a battery powered device such as a digital camera, the power consumption of the cooling element is considerably large considering the capacity of the battery. It is difficult, and a method of energizing and cooling only at the time of release has been proposed (see, for example, Patent Document 3).
JP 9-37161 A JP-A-10-256613 JP 2003-304420 A

  However, in the method proposed in Patent Document 1, the Peltier element generates a large amount of heat due to driving, and both the amount of heat absorbed and the amount of heat generated by itself are released to the side opposite to the endothermic surface. A large heat dissipating member is required, and it is very difficult to mount it on a small image pickup device such as a digital camera.

  Further, in the method proposed in Patent Document 2, an intermittent drive circuit is required to intermittently drive the Peltier element with a pulse current, so that the circuit of the apparatus becomes complicated and expensive. Furthermore, the heat generated on the heat generation side of the Peltier element during driving returns to the heat absorption side during non-driving, which in turn warms the image sensor, and in order to prevent this, a very large heat dissipation member is required. It is very difficult to mount on a small imaging device such as a camera.

  Furthermore, in the method proposed in Patent Document 3, when the Peltier element is not driven, heat may be returned from the heat dissipation side of the Peltier element to the imaging element to warm the imaging element. A heat radiating member is required, and it is very difficult to mount it on a small-sized imaging device such as a digital camera.

  The present invention has been made in view of the above circumstances, and provides an image pickup apparatus including a cooling element that can obtain high cooling efficiency with a simple configuration and is suitable for being mounted on a small image pickup apparatus such as a digital camera. The purpose is to provide.

  The object of the present invention can be achieved by the following constitution.

(Claim 1)
An image sensor for imaging a subject,
A first heat dissipating member that contacts the image sensor and radiates heat from the image sensor;
A cooling element that contacts the image sensor and cools the image sensor;
A second heat dissipating member that contacts the cooling element and dissipates heat from the cooling element;
An imaging unit comprising a heat insulating member that thermally separates the first heat radiating member and the second heat radiating member.

(Claim 2)
An image sensor for imaging a subject,
A first heat dissipating member that contacts the image sensor and radiates heat from the image sensor;
A cooling element that contacts the first heat dissipation member and cools the imaging element;
A second heat dissipating member that contacts the cooling element and dissipates heat from the cooling element;
An imaging unit comprising a heat insulating member that thermally separates the first heat radiating member and the second heat radiating member.

(Claim 3)
The imaging unit according to claim 1, wherein the heat insulating member is a circuit board.

(Claim 4)
The imaging unit according to claim 3, wherein the circuit board is a circuit board on which an imaging element is mounted.

(Claim 5)
An image sensor for imaging a subject,
A first heat dissipating member that contacts the image sensor and radiates heat from the image sensor;
A cooling element that contacts the image sensor and cools the image sensor;
A second heat dissipating member that contacts the cooling element and dissipates heat from the cooling element;
An image pickup unit comprising: a circuit board installed between the first heat radiating member and the second heat radiating member.

(Claim 6)
An image sensor for imaging a subject,
A first heat dissipating member that contacts the image sensor and radiates heat from the image sensor;
A cooling element that contacts the first heat dissipation member and cools the imaging element;
A second heat dissipating member that contacts the cooling element and dissipates heat from the cooling element;
An imaging unit comprising: a circuit board disposed between the first heat dissipation member and the second heat dissipation member.

(Claim 7)
The imaging unit according to claim 1, wherein the second heat radiating member has a larger heat radiating capacity than the first heat radiating member.

(Claim 8)
A contact portion where the imaging element and the first heat dissipation member abut, a contact portion where the image pickup device and the cooling element abut, and a contact portion where the cooling element and the second heat dissipation member abut. The imaging unit according to claim 1, wherein at least one abutting portion selected from the above is filled with a heat conductive material.

(Claim 9)
An imaging apparatus comprising the imaging unit according to claim 1.

(Claim 10)
Recording means for recording an image captured by the image sensor;
The image pickup apparatus according to claim 9, further comprising a control unit that drives the cooling element only at the time of imaging for the image sensor to record an image with the recording unit.

  According to the first aspect of the present invention, the first heat dissipating member that dissipates heat from the image sensor and the second heat dissipating member that dissipates heat from the cooling element that cools the image sensor are provided. By thermally separating the second heat radiating member, the heat of the cooling element can be prevented from returning from the second heat radiating member to the imaging element via the first heat radiating member, and the cooling efficiency can be improved.

  According to invention of Claim 2, it has the 1st heat radiating member which radiates the heat from an image sensor, and the 2nd heat radiating member which radiates the heat from the cooling element which cools the 1st heat radiating member, By thermally separating the first and second heat dissipating members, the heat of the cooling element can be prevented from returning from the second heat dissipating member to the image sensor via the first heat dissipating member, and the cooling efficiency can be improved. .

  According to the invention described in claim 3, by using the circuit board as the heat insulating member, a new heat insulating member is not required, which contributes to space saving and cost reduction.

  According to the invention described in claim 4, by using a circuit board on which an image sensor that is essential to be arranged in the vicinity of the image sensor is used as the heat insulation member, a new heat insulation member is not required and space saving and cost are reduced. Contribute to down.

  According to the invention of claim 5, the circuit board is disposed between the first heat radiating member that radiates heat from the image sensor and the second heat radiating member that radiates heat from the cooling element that cools the image sensor. Since it was provided, the heat radiation from the second heat radiating member to the first heat radiating member can be blocked by the circuit board, and the cooling efficiency of the image sensor can be improved.

  According to invention of Claim 6, between the 1st heat radiating member which radiates the heat from an image pick-up element, and the 2nd heat radiating member which radiates the heat from the cooling element which cools the 1st heat radiating member. Since the circuit board is provided, heat radiation from the second heat radiating member to the first heat radiating member can be blocked by the circuit board, and the cooling efficiency of the image sensor can be improved.

  According to the seventh aspect of the present invention, by increasing the heat dissipation capacity of the second heat dissipating member to be greater than that of the first heat dissipating member, the temperature of the image sensor can be cooled further, reducing dark noise and improving image quality. To contribute.

  According to the eighth aspect of the present invention, the thermal contact degree of the contact portion is further improved by filling each contact portion with a heat conductive material such as grease for heat dissipation, and the heat dissipation efficiency is further improved. To contribute.

  According to the invention described in claim 9, by mounting the imaging block according to any one of claims 1 to 6 in the imaging apparatus, an imaging apparatus with high image quality and low power consumption can be provided.

  According to the tenth aspect of the present invention, the cooling element is driven only at the time of image pickup for recording, thereby reducing the heat generation in the cooling element when the cooling element is always driven and improving the cooling efficiency. Contributes to reducing power consumption.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1A and 1B are schematic external views of a digital camera 1 that functions as an imaging apparatus according to the present invention. FIG. 1A is a front view and FIG. 1B is a rear view.

  On the front surface of the camera housing 10, a photographing lens 251, a flash light emitting unit 131a, and a viewfinder objective unit 141a are provided. A release button 121 and a mode setting dial 112 for setting an operation mode of the camera are provided at the upper part of the camera casing 10. An AF switch S1 and a release switch are provided at the lower part of the release button 121 inside the camera casing 10. A two-stage switch having a switch S2 is provided.

  On the back of the camera housing 10, a main switch 111 that is a power switch of the camera, a finder eyepiece 141b, an eyepiece display 142, a monitor 231 that displays a live view image and a captured image afterview, and a display on the monitor Is provided with a monitor switch 113 for controlling on / off.

  2 is a schematic vertical cross-sectional view (cross-section A-A ′ in FIG. 1) of the imaging apparatus illustrated in FIG. 1. In the figure, the same parts as those in FIG.

  The light from the subject collected by the photographing lens 251 forms an image on the image sensor 211. The image sensor 211 is mounted on a circuit board 261 on which circuit components (not shown) are mounted with the first heat radiating member 242 interposed therebetween. Further, the cooling side of the cooling element 241 is in contact with the back surface (the side opposite to the photographing lens) of the image sensor 211 and is in thermal contact therewith. A second heat radiating member 243 is in contact with the heat radiating side of the cooling element 241 and is in thermal contact therewith. A part of the second heat radiating member 243 is brought into contact with the inside of the camera housing 10 and is in thermal contact therewith. Accordingly, the heat generated by the image sensor 211 is radiated to the camera housing 10 through the cooling element 241 and the second heat radiating member 243 while being radiated by the first heat radiating member 242. Here, the circuit board 261 functions as a heat insulating member that thermally separates the first heat radiating member 242 and the second heat radiating member 243.

  Next, an example of the configuration of the imaging unit according to the first embodiment of the present invention will be described with reference to FIG. In the figure, the same parts as those in FIG.

  The imaging element chip 211a is die-bonded on a package 211b made of ceramic or the like, and is electrically connected to one end of a lead frame 211c by wire bonding (not shown), and is sealed with a cover glass 211d. The above is collectively referred to as an image sensor 211. A first heat radiating member 242 is in contact with the image sensor 211 and is in thermal contact therewith, with the first heat radiating member 242 interposed therebetween, and a lead frame in an opening 242 a provided in the first heat radiating member 242. The other end of 211c is electrically connected to the circuit board 261 by soldering or the like. Other circuit components (not shown) are also mounted on the circuit board 261 and are electrically connected to the image sensor 211.

  The imaging element 211 is in thermal contact with the heat absorbing surface 241a of the cooling element 241 at its bottom surface, and the heat radiating surface 241b of the cooling element 241 is in contact with the second heat radiating member 243. It is in close thermal contact. Further, the first heat radiating member 242 and the second heat radiating member 243 are thermally separated by sandwiching the circuit board 261 therebetween. The circuit board 261 is made of glass epoxy, polyimide, or the like, and in a region sandwiched between the first heat radiating member 242 and the second heat radiating member 243 and in the vicinity thereof, a wide metal surface such as a power source, a ground, a shield, or a wiring resistance It is preferable that there are few portions with good heat conduction, such as a large number of through holes for reducing the value. In this example, a portion 243a of the second heat radiating member 243 that abuts on the heat radiating surface 241b of the cooling element 241 is raised to a convexity difference between the thickness of the cooling element 241 and the circuit board 261, thereby providing the second heat radiating member 243. As shown in FIG. 4, the adhesion between the heat radiation surface 241b of the cooling element 241 and the heat radiation surface 241b of the cooling element 241 is improved. The surface may be a flat surface without concavity and convexity, or conversely, as shown in FIG. Furthermore, in order to achieve the above-mentioned “thermal contact”, each contact portion is filled with a heat conductive material such as a heat dissipation grease, a heat dissipation sheet, a heat conductive filler, or a heat conductive adhesive. May be.

  The first heat radiating member 242 does not drive the cooling element until the temperature T1 at which the image output of the imaging element chip 211a becomes a noise level that does not interfere with the live view or AF / AE during live view or AF / AE. The image pickup device chip 211a is set to a size having a sufficient heat dissipation capacity to dissipate the temperature.

  The cooling element 241 has a cooling capability capable of rapidly cooling the image pickup element chip 211a to a temperature T2 (T2 <T1) at which an image output of the image pickup element chip 211a becomes a noise level sufficient for viewing as an image during photographing. Set to have. The second heat dissipation member 243 is sufficient to dissipate both the heat generated by the image sensor chip 211a and the heat generated by the cooling element 241 when the image sensor chip 211a is rapidly cooled by the cooling element 241 as described above. It is set to a size with heat dissipation capacity. That is, the amount of heat to be radiated is larger in the second heat radiating member 243 than in the first heat radiating member 242. Therefore, the heat dissipation capacity of the second heat dissipation member 243 needs to be larger than the heat dissipation capacity of the first heat dissipation member 242. Therefore, in FIGS. 2 and 3, the second heat radiating member 243 is made larger than the first heat radiating member 242 and the heat radiating efficiency is increased by attaching the heat radiating fins 243 b. It is not limited to.

  An example of the configuration of the imaging unit according to the second embodiment of the present invention will be described with reference to FIG. In the figure, the same parts as those in FIGS. 2 and 3 are denoted by the same reference numerals, only the parts different from those in FIG. 3 will be described, and common parts will be omitted.

  A first heat radiating member 242 is in contact with the image pickup device 211 and is in thermal contact therewith, and the first heat radiating member 242 is sandwiched therebetween, and the other end of the lead frame 211c is electrically connected to the circuit board 261 by soldering or the like. Connected. The bottom surface of the first heat radiating member 242 is in thermal contact with the heat absorbing surface 241 a of the cooling element 241, and the heat radiating surface 241 b of the cooling element 241 is in contact with the second heat radiating member 243. And are in close thermal contact. Further, the first heat radiating member 242 and the second heat radiating member 243 are thermally separated by sandwiching the circuit board 261 therebetween. In this example, the portion 243a of the second heat radiating member 243 that contacts the heat radiating surface 241b of the cooling element 241 is a flat surface, but the adhesion between the second heat radiating member 243 and the heat radiating surface 241b of the cooling element 241 is made. 3 may be convex as shown in FIG. 3, or conversely as shown in FIG. 5.

  With the above-described configuration, the heat of the image sensor 211 is radiated by the first heat radiating member 242 when the cooling element is not driven, and is cooled via the first heat radiating member 242 when the cooling element is driven. Heat is absorbed by the element and cooled. In this example, the second heat radiating member 243 is not provided with the heat radiating fins 243b.

  Furthermore, an example of the configuration of the imaging unit according to the third embodiment of the present invention will be described with reference to FIG. In the figure, the same parts as those in FIGS. 2, 3 and 4 are given the same numbers, only the parts different from those in FIG. 3 will be described, and the common parts will be omitted.

  The image pickup device chip 211a is die-bonded on a package 211b made of plastic or the like, is wire-bonded (not shown) to one end of a lead frame 211c, is electrically connected, and is sealed with a cover glass 211d. A cooling plate 211e made of a metal warehouse or the like is provided on the bottom surface of the package 211b. The above is collectively referred to as an image sensor 211. A first heat radiating member 242 is in contact with the bottom surface of the image sensor 211 and is in thermal contact with the cooling plate 211e, and is provided on the first heat radiating member 242 with the first heat radiating member 242 interposed therebetween. The other end of the lead frame 211c is inserted into the opening 242a and electrically connected to the circuit board 261 by soldering or the like. Other circuit components (not shown) are also mounted on the circuit board 261 and are electrically connected to the image sensor 211.

  In addition, the imaging element 211 is in thermal contact with the cooling plate 211e with the heat absorption surface 241a of the cooling element 241 being in contact with the bottom surface portion thereof, and the heat radiation surface 241b of the cooling element 241 is the second heat radiation member 243. And are in thermal contact with each other. Further, the first heat radiating member 242 and the second heat radiating member 243 are thermally separated by sandwiching the circuit board 261 therebetween. In this example, the portion 243a of the second heat radiating member 243 that is in contact with the heat radiating surface 241b of the cooling element 241 is dug into the concave difference between the thickness of the cooling element 241 and the circuit board 261, thereby the second heat radiating member 243. As shown in FIG. 3, the adhesion between the heat radiation surface 241b of the cooling element 241 and the heat radiation surface 241b of the cooling element 241 is improved. It may be a convex surface or a flat surface as shown in FIG.

  With the above-described configuration, the heat of the image sensor 211 is radiated by the first heat radiating member 242 via the cooling plate 211e when the cooling element is not driven, and the cooling plate 211e when the cooling element is driven. Then, the heat is absorbed by the cooling element and cooled. In this example, the second heat radiating member 243 is not provided with the heat radiating fins 243b.

  Next, a circuit of the digital camera 1 that functions as an imaging device according to the present invention will be described with reference to FIG. FIG. 6 is a circuit block diagram of the digital camera 1. In the figure, the same parts as those in FIGS.

  The camera controller 101 serving as a control unit includes a CPU (central processing unit) (not shown), a work memory, and the like, reads a program stored in a storage unit (not shown) into the work memory, and controls each unit of the digital camera 1 according to the program. Centralized control.

  The camera controller 101 receives inputs from the main switch 111, AF switch S1, release switch S2, mode setting dial 112, and monitor switch 113 to control the operation of each part of the camera, and to perform image processing and image control. In cooperation with the digital processing unit 201, AF control, aperture control, and light emission control of the flash 131 are performed via the lens control unit 171. Furthermore, the camera controller 101 displays various types of information on an eyepiece display unit 142 provided in or near the viewfinder eyepiece.

  In addition, the camera controller 101 controls energization to the cooling element 241 for cooling the imaging element 211 according to a flowchart described later.

  The light from the subject collected by the photographing lens 251 forms an image on the image sensor 211. A cooling element 241 for cooling the image sensor 211 is disposed in contact with the image sensor 211. The image output picked up by the image sensor 211 is subjected to predetermined processing by the analog processing unit 212 and then converted into digital data by the A / D conversion unit 213, and predetermined signal processing and image processing by the digital processing unit 201. Is temporarily stored as image data in the image memory 221 and displayed as a live view image on the monitor 231.

  When the release switch S2 is turned on, imaging for recording (hereinafter referred to as imaging) is performed according to a flowchart described later, and after image data is temporarily stored in the image memory 221, it is after-saved as a captured image on the monitor 231. The view is displayed and stored in the memory card 231. The operations of the image sensor 211, the analog processing unit 212, and the A / D conversion unit 213 are controlled by the timing generator 214 and the V driver 215. Description of the details of the control is omitted. The imaging element 211, the analog processing unit 212, the A / D conversion unit 213, the timing generator 214, and the V driver 215 are collectively referred to as an imaging unit 210.

  In the power supply unit 151 that controls the power supply of each part of the camera, the battery 161 uses V1 (= 15 V), V2 (= 5 V), V3 (= 3.3 V), V4 (= −7. 5V) is generated and supplied to each part of the camera.

  Next, control of the imaging operation of the digital camera 1 as the imaging apparatus according to the present invention will be described with reference to FIG. FIG. 7 is a flowchart showing a flow of shooting with the digital camera 1.

  First, when the main switch 111 is operated in step S01 and the camera is turned on, the operation mode at the time of activation is determined in step S02. Here, the camera mode is activated on the assumption that the “camera mode” for capturing an image using the mode setting dial 112 is set. The description of the control in an operation mode other than the camera mode (for example, the playback mode) is omitted.

  When the camera mode is activated (step S02; YES), the power of the imaging unit 210 is turned on in step S11. In step S12, live view display is performed on the monitor 231, and in step S13, it is determined whether or not the AF switch S1 is turned on. The process waits in step S13 until the AF switch S1 is turned on.

  When the AF switch S1 is turned on (step S13; YES), AF and AE are performed in step S14, and it is determined whether the release switch S2 is turned on in step S15. Steps S13 to S15 are repeated until the release switch S2 is turned on.

  When the release switch S2 is turned on (step S15; YES), the cooling element 241 is energized in step S16, and cooling of the imaging element 211 is started. Shooting is performed in step S17, and image output is transferred from the image sensor 211 to the analog processing unit 212 in step S18, and converted into digital data by the A / D conversion unit 213. When the transfer of the image output is completed, energization to the cooling element 241 is stopped in step S19, and the cooling of the imaging element 211 is completed.

  In step S20, the captured image data is temporarily stored in the image memory 221. In step S21, the captured image is displayed on the monitor 231 (after-view display), and the image data captured in step S22 is stored in the memory. Recorded on the card 222.

  After a certain period of time has elapsed since the after view display in step S21, the after view display on the monitor 231 is turned off in step S23, and the live view display is again performed on the monitor 231 in step S24. In step S25, it is determined whether auto power off (APO: predetermined time, function to turn off power when no operation is performed) has elapsed, and if not (step S25; NO), it is determined in step S26 whether or not the main switch 111 is turned off.

  If not turned off (step S26; NO), it is determined in step S27 whether or not the operation mode has been changed from the camera mode. If it has not been changed (step S27; YES), the process returns to step S12 and the above sequence is repeated. If the operation mode has been changed (step S27; NO), the control proceeds to the changed mode. The description of the control in an operation mode other than the camera mode (for example, the playback mode) is omitted.

  When the APO time has elapsed in step S25 (step S25; YES) and when the main switch 111 is turned off in step S26 (step S26; YES), the live view on the monitor 231 is turned off in step S31. In step S32, the power source of the imaging unit 210 is turned off. This is the end of shooting.

  Next, the operation of the circuits around the image sensor 211 and the cooling element 241 and the temperature of the image sensor chip 211a in the processing flow shown in FIG. 7 will be described with reference to FIG. FIG. 8A is a timing chart showing the operation timing of each step of FIG. 7, and FIG. 8B is the temperature in the operation shown in FIG. 8A of the image sensor chip 211a according to the present invention. FIG. 8C is a schematic diagram showing a temperature transition in the operation shown in FIG. 8A of the first heat radiating member 242 according to the present invention. FIG. 8D is a schematic diagram showing a change in temperature in the operation shown in FIG. 8A of the second heat radiating member 243 according to the present invention.

  First, in FIG. 8A, when the main switch 111 is turned on in step S01 and activated in the camera mode, imaging for live view is started and the live view is displayed on the monitor 222. Next, when it is confirmed in step S13 that the AF switch S1 is on (step S13; YES), AF and AE are performed. Subsequently, when it is confirmed in step S15 that the release switch S2 is turned on (step S15; YES), energization of the cooling element 241 is started in step S16.

  Since the cooling element 241 does not operate from the start in the camera mode to the start of energization to the cooling element 241, as shown in FIGS. 8B and 8C, the imaging element chip 211a and the first heat radiation member The temperature of 242 continues to increase little by little at first, and eventually reaches temperature equilibrium. The temperature of the second heat radiating member 243 is also the same as that of the image sensor chip 211a and the first heat radiating member 242 as shown in FIG. 8D because the heat of the image sensor chip 211a is transmitted through the cooling element 241. Draw a temperature rise curve. The first heat radiating member 242 is set so that the equilibrium temperature of the image pickup device chip 211a is equal to or lower than the above-described “temperature T1 at which the image output of the image pickup device chip 211a becomes a noise level that does not hinder live view or AF / AE”. The heat dissipation capacity is set.

  When energization of the cooling element 241 is started in step S16, the temperature of the imaging element chip 211a starts to decrease. At the time when shooting is performed in step S17, the temperature of the image sensor chip 211a is equal to or lower than the above-described “temperature T2 at which the image output of the image sensor chip 211a has a noise level sufficient for viewing as an image”. In addition, the second heat radiating member 243 has a cooling capability that can absorb both heat amounts of the first heat radiating member 242 transmitted through the image sensor 211 and the image sensor 211. It is set to have a heat radiation capacity that can dissipate both the heat quantity of the image pickup device 211 and the first heat radiation member 242 that have absorbed heat and the heat quantity generated by the cooling element 241 during cooling.

  Next, shooting is performed in step S17, and the image output is transferred to the analog processing unit 212 for processing in step S18, and A / D conversion is performed in the A / D conversion unit 213. During this time, since the cooling element 241 is energized, as shown in FIG. 8B, the temperature of the imaging element chip 211a falls below T2, and eventually reaches temperature equilibrium. As shown in FIG.8 (c), the 1st thermal radiation member 242 also shows the same temperature curve. As shown in FIG. 8D, the temperature of the second heat radiation member 243 rises due to heat radiation, and eventually reaches temperature equilibrium.

  In this example, the power supply to the cooling element 241 is not particularly controlled. For example, after the temperature of the imaging element chip 211a becomes equal to or lower than T2, the power supply to the cooling element 241 is intermittently performed. Further reduction of power may be performed.

  When the energization to the cooling element 241 is finished in step S19, the temperature of the imaging element chip 211a starts to rise again, and after the after view display in step S21, the live view display for the next shooting in step S24. Then, the above steps are repeated and the above temperature transition is repeated in terms of temperature.

  In the present embodiment, the start of energization of the cooling element 241 (step S16) is placed after the release switch S2 is turned on in step S15. Instead, the AF switch S1 is turned on in step S13. After or after AF and AE are performed in step S14.

  The cooling element 241 includes, for example, a Peltier element, and the cooling plate 211e includes, for example, a metal such as aluminum.

  In addition, the detailed configuration and the detailed operation of each configuration configuring the imaging apparatus according to the present invention can be changed as appropriate without departing from the spirit of the present invention.

1 is a schematic external view of an imaging apparatus according to the present invention. FIG. 2 is a schematic diagram of an A-A ′ cross section in FIG. 1 of the imaging device illustrated in FIG. 1. It is a schematic diagram of the structural example of the imaging unit which concerns on the 1st Embodiment of this invention. It is a schematic diagram of the structural example of the imaging unit which concerns on the 2nd Embodiment of this invention. It is a schematic diagram of the structural example of the imaging unit which concerns on the 3rd Embodiment of this invention. 1 is a circuit block diagram of an imaging apparatus according to the present invention. It is a flowchart which shows the flow of imaging | photography in the imaging device which concerns on this invention. FIG. 8A is a timing chart showing the operation timing of each part of the image pickup apparatus according to the present invention, and FIG. 8B is the operation of the image pickup device chip according to the present invention in the operation shown in FIG. FIG. 8C is a schematic diagram showing a temperature transition in the operation shown in FIG. 8A of the first heat dissipating member according to the present invention. FIG. 8D is a schematic diagram showing a temperature transition in the operation shown in FIG. 8A of the second heat radiating member according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Digital camera 10 Camera housing 101 Camera controller 111 Main switch 112 Mode setting dial 113 Monitor switch 121 Release button S1 AF switch S2 Release switch 131 Flash 141 Viewfinder 141a Viewfinder objective 141b Viewfinder eyepiece 142 Eyepiece display 151 Power supply 161 Battery 171 Lens control unit 201 Digital processing unit 210 Imaging unit 211 Imaging device 211a Imaging device chip 211b Package 211c Lead frame 211d Cover glass 211e Cooling plate 212 Analog processing unit 213 A / D conversion unit 214 Timing generator 215 V driver 221 Image memory 222 Memory card 231 Monitor 241 Cooling element 241a Endothermic surface 241b Hot Surface 242 first radiating member 243 second heat radiating member 243a abutting portion 243b radiating fins 251 photographic lens 252 aperture 261 circuit board to the cooling device of the second heat radiating member

Claims (10)

An image sensor for imaging a subject,
A first heat dissipating member that contacts the image sensor and radiates heat from the image sensor;
A cooling element that contacts the image sensor and cools the image sensor;
A second heat dissipating member that contacts the cooling element and dissipates heat from the cooling element;
An imaging unit comprising a heat insulating member that thermally separates the first heat radiating member and the second heat radiating member. An image sensor for imaging a subject,
A first heat dissipating member that contacts the image sensor and radiates heat from the image sensor;
A cooling element that contacts the first heat dissipation member and cools the imaging element;
A second heat dissipating member that contacts the cooling element and dissipates heat from the cooling element;
An image pickup unit comprising a heat insulating member that thermally separates the first heat radiating member and the second heat radiating member. The imaging unit according to claim 1, wherein the heat insulating member is a circuit board. The imaging unit according to claim 3, wherein the circuit board is a circuit board on which an imaging element is mounted. An image sensor for imaging a subject,
A first heat dissipating member that contacts the image sensor and radiates heat from the image sensor;
A cooling element that contacts the image sensor and cools the image sensor;
A second heat dissipating member that contacts the cooling element and dissipates heat from the cooling element;
An imaging unit comprising: a circuit board disposed between the first heat dissipation member and the second heat dissipation member. An image sensor for imaging a subject,
A first heat dissipating member that contacts the image sensor and radiates heat from the image sensor;
A cooling element that contacts the first heat dissipation member and cools the imaging element;
A second heat dissipating member that contacts the cooling element and dissipates heat from the cooling element;
An imaging unit comprising: a circuit board disposed between the first heat dissipation member and the second heat dissipation member. The imaging unit according to claim 1, wherein the second heat radiating member has a larger heat radiating capacity than the first heat radiating member. A contact portion where the imaging element and the first heat dissipation member abut, a contact portion where the image pickup device and the cooling element abut, and a contact portion where the cooling element and the second heat dissipation member abut. The imaging unit according to claim 1, wherein at least one abutting portion selected from the above is filled with a heat conductive material. An imaging apparatus comprising the imaging unit according to claim 1. Recording means for recording an image captured by the image sensor;
The image pickup apparatus according to claim 9, further comprising a control unit that drives the cooling element only at the time of imaging for the image sensor to record an image with the recording unit.

Images