Imaging device

Abstract

To provide an imaging device that can satisfy heat dissipation performance without hindering the movement of the image sensor. [Solution] The imaging device 100 has an image sensor unit 106 which includes an image sensor 115, a movable part 114 that supports the image sensor, and a drive mechanism 113 that moves the movable part in a direction including a direction perpendicular to the optical axis direction, and a blower 130, wherein the blower is positioned outside the range of motion of the movable part when viewed from the optical axis direction, and the drive mechanism is not positioned between the blower and the movable part.

Description

Technical Field

[0001] The present invention relates to an imaging device having a heat dissipation structure for heat generated from a heat source.

Background Art

[0002] In recent years, with the demand for miniaturization of imaging devices, the miniaturization and high density of mounting components inside the imaging device have become remarkable. On the other hand, while the demand for high functionality of imaging devices, particularly for high performance of video functions, is increasing, the amount of heat generated by the imaging device has a tendency to increase. The temperature rise inside the imaging device during video shooting in a high-temperature environment is likely to cause malfunction or performance degradation of the mounting components, and ultimately failure of the imaging device.

[0003] In addition, in recent years, an imaging device that performs shake correction by moving an imaging element in a direction orthogonal to the optical axis direction in order to improve image quality has become widespread. Even in such an imaging device that performs shake correction, sufficient heat dissipation is required because the heat generated in the imaging element affects the image quality during driving of the shake correction mechanism, during continuous shooting, or during video shooting.

[0004] Therefore, when the amount of heat dissipation by natural heat dissipation is not sufficient for the amount of heat generated by the imaging device, a heat dissipation structure by forced air cooling using a heat conduction member is used.

[0005] Patent Document 1 discloses an optical unit that cools an imaging element by connecting a heat conduction member to the movable imaging element.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, the optical unit disclosed in Patent Document 1 has the problem that the heat conductive member is physically connected to the movable image sensor, which hinders the operation of the image sensor.

[0008] The present invention provides an imaging device that satisfies heat dissipation performance without hindering the movement of the image sensor. [Means for solving the problem]

[0009] An imaging device as one aspect of the present invention comprises an image sensor section comprising an image sensor, a movable part supporting the image sensor, and a drive mechanism for moving the movable part in a direction including a direction perpendicular to the optical axis direction, and a blower means, wherein the blower means is positioned outside the range of motion of the movable part when viewed from the optical axis direction, and the drive mechanism is not positioned between the blower means and the movable part.

[0010] Other objects and features of the present invention are described in the following embodiments. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an imaging device that can satisfy heat dissipation performance without hindering the movement of the image sensor. [Brief explanation of the drawing]

[0012] [Figure 1] This is a rear exploded perspective view of the digital camera 100 according to this embodiment. [Figure 2] This is a front exploded perspective view of the image sensor unit 106 according to this embodiment. [Figure 3] This is a rear exploded perspective view of the image sensor unit 106 according to this embodiment. [Figure 4] This is a rear view of the image sensor unit 106 and the heat dissipation fan 130 according to this embodiment. [Figure 5] This is a schematic diagram of the rear view of the image sensor unit 106 and the heat dissipation fan 130 according to this embodiment. [Figure 6]This is a schematic diagram of the rear view of the image sensor unit 106 and the heat dissipation fans 130a and 130b according to a modified example of this embodiment. [Figure 7] This is a block diagram of the digital camera 100 according to this embodiment. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described in detail below with reference to the drawings. The dimensions, materials, shapes, and relative arrangements of the components described below should be appropriately modified depending on the configuration of the apparatus to which the invention is applied and various conditions. Therefore, the scope of the present invention is not limited to the following description. In particular, well-known or prior art in the relevant field can be applied to configurations and processes that are not illustrated or described. Also, redundant explanations may be omitted. In the drawings, the same reference numerals are used between drawings to indicate elements that are the same or functionally similar.

[0014] Figure 1 is an exploded rear perspective view of the digital camera 100, which is an imaging device according to this embodiment. As shown in Figure 1, the digital camera 100 consists of a mount section 102a, a rear cover 101, a front base 102, a top cover 103, a bottom cover 104, and a side cover 105.

[0015] Inside the digital camera 100 are an image sensor unit 106 with an image stabilization mechanism, a main circuit board 107, a shutter 108, a viewfinder 109, and a chassis 110. The image sensor unit 106 consists of a movable part 114 that supports the image sensor 115 and a fixed part 113 which is a drive mechanism for driving the movable part 114.

[0016] The image sensor unit 106 is positioned perpendicular to the optical axis OA, and the image sensor 115 is also positioned perpendicular to the optical axis OA. Here, "perpendicular to the optical axis" includes not only cases where it is strictly perpendicular to the optical axis, but also cases where it is approximately perpendicular to the optical axis. Hereafter, when simply referred to as "perpendicular," it will be interpreted as including "approximately perpendicular."

[0017] The front base 102 is formed of, for example, magnesium die-casting or resin, and includes a mount portion 102a to which an interchangeable lens can be attached. The main board 107 is composed of a multilayer board, and electronic components are mounted on both sides. The main board 107 is screwed to the front base 102 and a metal chassis 110. On the main board 107, a control IC 107a for controlling an imaging signal and the like, a recording medium connector 107b for housing an external recording medium, and an external communication terminal 107c for connecting a connection cable with an external device are mounted. The external communication terminal 107c is covered with a terminal cover 105a.

[0018] The imaging element unit 106 consumes particularly large power and generates a large amount of heat among the components of the digital camera 100. Therefore, the imaging element unit 106 is a member where the temperature rises rapidly. The shooting time of the digital camera 100 is limited by the operating guaranteed temperature of each component. In order to maintain the shooting time as long as possible, it is necessary to dissipate the heat of the imaging element unit 106, which is a heat source, and take measures so as not to exceed the operating guaranteed temperature. The imaging element unit 106 is screwed to the front base 102, and the heat of the imaging element unit 106 is configured to escape to the front base 102.

[0019] The heat radiation fan 130 is arranged around the imaging element unit 106 such that the blowing direction is perpendicular to the optical axis OA, and air directly passes over the back surface of the imaging element unit 106, which is a heat source. Thereby, it is prevented that the imaging element unit 106 becomes locally high in temperature (details will be described later). Further, in the present embodiment, the centrifugal fan is used as the blowing means for the heat radiation fan 130, but if the object can be achieved, for example, an axial flow fan or the like may be used. Also, in the present embodiment, the heat radiation fan 130 is arranged such that the blowing direction is perpendicular to the optical axis OA, but this is not the case as long as the air flow from the heat radiation fan 130 directly hits the imaging element unit 106, and it may be arranged such that the blowing direction is not perpendicular to the optical axis OA.

[0020] The details of the imaging element unit 106 will be described using FIGS. 2 and 3. FIG. 2 is a front exploded perspective view of the imaging element unit 106, and FIG. 3 is a rear exploded perspective view of the imaging element unit 106.

[0021] The imaging element unit 106 is composed of a movable part 114 and a fixed part 113 which is a driving mechanism. The fixed part 113 can perform shake correction by moving the movable part 114 in a direction orthogonal to the optical axis direction. Note that the movable part 114 may be moved in a direction including the direction orthogonal to the optical axis direction. The movable part 114 is provided with a coil part 116 in which a coil and a Hall element for moving the imaging element 115 are arranged. The imaging element 115 is held by a sensor holder 117 of the movable part 114. Three magnets 118 are held on the driving mechanism 113 side, and the movable part 114 is adsorbed and held by the magnets 118. Between the movable part 114 and the driving mechanism 113, balls (not shown) are placed in a ball holding part 117a provided on the sensor holder 117. The movable part 114 can be moved by changing the energization amount of the coil part 116. Shake correction (camera shake correction) can be applied by moving the movable part 114 in a direction to cancel out the shake of the digital camera 100 main body. Note that the coil part 116, the magnets 118, etc. necessary for driving the movable part 114 are regarded as a part of the driving mechanism 113.

[0022] The imaging element 115 has a sensor chip (not shown) adhered to an imaging substrate 115a on which an imaging circuit is mounted, and is electrically connected to the imaging substrate 115 by wire bonding. The imaging element 115 and the sensor holder 117 are adhered and fixed with an adhesive. Elements 115b such as capacitors, resistors, and regulators of the imaging circuit are mounted on the back surface of the sensor chip attachment surface on the imaging substrate 115a.

[0023] The electrical connection between the image sensor unit 106 and the main board 107 is made using a flexible wiring board. The imaging signal output from the image sensor 115 and the control signals necessary for driving the image sensor 115 are transmitted to the control IC 107a on the main board 107 via the imaging signal flexible circuit 111. The imaging power supply flexible circuit 112 is a flexible circuit that supplies power to drive the image sensor 115. Inter-board connectors are used to connect the imaging board 115a to each of these flexible circuits.

[0024] Figures 4 and 5 show the heat dissipation fan 130 and the image sensor unit 106 as viewed from the back in the optical axis direction, and a schematic diagram thereof, respectively.

[0025] Here, we will explain the relationship between the movement of the movable part 114 of the image sensor unit 106 and the position of the heat dissipation fan 130. The movable part 114 can move perpendicular to the optical axis OA, and the range of movement of the movable part 114 is shown in range 114a in Figure 5. Furthermore, range 114b is shown as the range in which the diagonal 114c of the movable part 114 (or the diagonal of the image sensor 115) always exists when the movable part 114 moves. This range 114b is the range in which the diagonal 114c of the movable part 114 exists no matter where the movable part 114 moves within range 114a.

[0026] Next, the arrangement of the cooling fan 130 will be described. As mentioned above, the cooling fan 130 is positioned outside the movable range 114a of the movable part 114 when viewed from the optical axis direction, so that the air discharged from the exhaust port 131 of the cooling fan 130 passes over the back surface of the image sensor 106. Furthermore, in order to ensure that the air passes over the range 114b where the diagonal 114c of the movable part 114 always exists when the movable part 114 moves, the cooling fan 130 is positioned so that the direction in which the exhaust port 131 is facing is within the range 114b. In other words, the cooling fan 130 is positioned so that no matter what position the movable part 114 moves to, there is a diagonal 114c extending in the direction in which the exhaust port 131 is facing. Here, the general direction of airflow from the cooling fan 130 is shown in 131a. Because the airflow direction 131a is within range 114b, the air can pass through the diagonal 114c, which has the longest airflow distance, regardless of the position of the movable part 114, which is the heat source of the image sensor 106. This allows for a higher heat dissipation effect.

[0027] Furthermore, it is preferable that the cooling fan 130 and the image sensor 115 are positioned at approximately equal positions in the optical axis direction. This allows air to reach the sides of the image sensor 115, thereby suppressing the temperature rise of the image sensor 115. More preferably, the cooling fan 130 and the image sensor 115 are positioned at equal positions in the optical axis direction.

[0028] Furthermore, the cooling fan 130 is positioned such that components such as the coil section 116 and magnet 118 necessary for driving the movable part 114 are not located in the airflow path of the cooling fan 130. In other words, the drive mechanism 113 is not located between the cooling fan 130 and the movable part 114. This prevents obstruction of the airflow from the cooling fan 130. Not only are components such as the coil section 116 and magnet 118 necessary for driving the movable part 114 excluded, but by not placing any components that obstruct the airflow between the cooling fan 130 and the diagonal 114c of the movable part 114, a higher heat dissipation effect can be obtained.

[0029] Furthermore, in this embodiment, since the heat conduction member for heat dissipation is not physically connected to the movable part 114, it is possible to generate a heat dissipation effect without hindering the image stabilization function due to the movement of the movable part 114.

[0030] In this embodiment, for example, the cooling fan 130 is operating at a wind speed of 4.5 L / min. Liters per minute (L / min) is a unit of volumetric flow rate. By incorporating the cooling fan 130 into the digital camera 100, it is possible to reduce the maximum temperature reached by the image sensor 106 by 10°C. This suppresses the temperature rise of the heat source, making it less likely for the digital camera 100 to reach the limit temperature at which it will stop functioning due to overheating.

[0031] Figure 6 is a schematic rear view of the image sensor unit 106 and a plurality of heat dissipation fans 130a, 130b according to a modified example of this embodiment. In the embodiment described above, a single heat dissipation fan 130 was used to achieve the heat dissipation effect, but multiple heat dissipation fans 130a, 130b may be used. By using multiple heat dissipation fans 130a, 130b to blow air onto the heat source, the heat dissipation effect on the heat source can be further enhanced. For example, as shown in Figure 6, a first blowing means 130a and a second blowing means 130b are arranged as two heat dissipation fans. Specifically, the first blowing means 130a is positioned such that the blowing direction 131a1 of the first blowing means 130a is parallel to one diagonal 114c1 of the movable part 114 when viewed from the optical axis direction. Then, the second air blower 130b is positioned such that, when viewed from the optical axis direction, the air blowing direction 131b1 of the second air blower 130b is parallel to the other diagonal 114c2 of the movable part 114. Here, "parallel to the diagonal" means not only the case where it is strictly parallel to the diagonal, but also the case where it is approximately parallel to the diagonal. With the air blowing direction 131a1 within range 114b1, no matter where the movable part 114, which is the heat source of the image sensor 106, moves, the air can pass through the diagonal 114c1 with the longest air blowing distance. Also, with the air blowing direction 131b1 within range 114b2, no matter where the movable part 114, which is the heat source of the image sensor 106, moves, the air can pass through the diagonal 114c2 with the longest air blowing distance. This allows for a higher heat dissipation effect.

[0032] Figure 7 is a block diagram showing an example configuration of the digital camera 100 in this embodiment.

[0033] The shutter 410 is a focal-plane shutter that can freely control the exposure time of the imaging unit 411, which will be described later. This control is performed by the system control unit 420, which will be described later. The imaging unit 411 is an imaging device that has an imaging surface on which the subject image (optical image) that has passed through the lens 501 is formed, and outputs an electrical signal (analog signal) corresponding to the optical image on the imaging surface by photoelectric conversion. A CCD (Charge Couple Device) or a CMOS (Complementary MOS) sensor can be used as the imaging unit 411.

[0034] The A / D converter 412 is a signal conversion means used to convert the analog signal output from the imaging unit 411 into a digital signal.

[0035] The image processing unit 413 is an image processing means that generates image data by performing resizing processing such as predetermined pixel interpolation and reduction, and color conversion processing on the digital signal from the A / D converter 412 or the digital signal from the memory control unit 422 (described later). Based on the calculation results obtained by the image processing unit 413, the system control unit 420 controls the aperture position and the lens position. The image processing unit 413 further performs calculation processing using the image data and performs TTL-type AWB (auto white balance) processing based on the obtained calculation results.

[0036] The system control unit 420 is a control unit consisting of at least one processor or circuit, and controls the entire digital camera 400. The system control unit 420 performs various processes by executing a program recorded in the non-volatile memory 423, which will be described later.

[0037] The memory 421 is a storage means for temporarily recording digital signals obtained by the imaging unit 411 and converted by the A / D converter 412, as well as image data generated by the image processing unit 413. The memory 421 has sufficient storage capacity to store a predetermined number of still images, a predetermined amount of video footage, and audio.

[0038] The memory control unit 422 is a memory control means that controls the transmission and reception of data controlled by the system control unit 420 with the A / D converter 412, image processing unit 413, and memory 421.

[0039] The digital signal output from the A / D converter 412 is written directly to the memory 421 via the image processing unit 413 and the memory control unit 422, or via the memory control unit 422 alone.

[0040] The non-volatile memory 423 is an electrically erasable and recordable read-only storage means that stores constants, programs, etc., for the operation of the system control unit 420. The system memory 424 is a read-and-write storage means that stores constants, variables, programs, etc., for the operation of the system control unit 420, as well as programs read from the non-volatile memory 423.

[0041] The system timer 425 is a timing unit that measures the time until the auto power-off operation, which turns off the various display components described later, is performed, as well as the exposure time.

[0042] The auto power-off function has the ability to turn off various indicator lights (described later) to prevent battery drain when it determines that the photographer is not operating the digital camera 100.

[0043] The power supply unit 430 consists of primary batteries such as alkaline batteries and lithium batteries, secondary batteries such as NiCd batteries, NiMH batteries and Li batteries, and an AC adapter.

[0044] The power control unit 431 consists of a circuit for detecting the power supply unit 430, which is the power source for driving the digital camera 100, a DC-DC converter, a switch circuit for switching the power supply destination, and the like. The power control unit 431 also detects whether a battery is installed, the type of battery, and the remaining battery level. Furthermore, the power control unit 431 controls the DC-DC converter based on the above detection results and instructions from the system control unit 420, and supplies the necessary voltage to the power supply destination at the necessary timing.

[0045] The communication terminal 440 is provided on the digital camera 100 and is electrically connected to the lens communication terminal 506, which will be described later. The electrical connection of the communication terminal 440 enables the system control unit 420, which controls the entire digital camera 100, to communicate with the lens 500, which will be described later.

[0046] The recording medium I / F441 is an interface with the recording medium 600, which will be described later.

[0047] The attitude detection unit 442 detects the attitude of the digital camera 100 relative to the direction of gravity. Based on the attitude detected by the attitude detection unit 442, the system control unit 420 can output orientation information indicating whether the image captured by the imaging unit 411 was taken with the digital camera held horizontally or vertically. The system control unit 420 can add the orientation information output by the attitude detection unit 442 to the image data. An acceleration sensor or a gyro sensor can be used as the attitude detection unit 442. If an acceleration sensor and a gyro sensor are used as the attitude detection unit 442, it is also possible to detect the movement of the digital camera 100 (pan, tilt, lift, whether it is stationary or not, etc.).

[0048] The eyepiece section 443 is the point where the photographer's eye (object) 700 approaches (eyepieces) the digital camera 100.

[0049] The eyepiece detection unit 444 is a proximity or eyepiece detection sensor that detects when the eye 700 approaches (eyepieces) and moves away from (eyes away from) the eyepiece unit 443. The eyepiece detection unit 444 detects when the eye 700 approaches the eyepiece unit 443 based on the presence or absence of light reception by the light receiving unit (not shown) of an infrared proximity sensor. After detecting eyepiece contact, the system control unit 420 determines that the eyepiece is in a contact state until eye-away is detected. After detecting eye-away, the system control unit 420 determines that the eyepiece is not in a contact state until eyepiece contact is detected again. Note that the infrared proximity sensor is just one example, and the eyepiece detection unit 444 may use any other sensor that can detect the approach of an eye or object that can be considered as an eyepiece.

[0050] The aforementioned memory 421 also serves as a memory for image display (video memory). Digital signals and image data written to memory 421 are displayed by the rear display unit 450 and EVF 451 via the memory control unit 422.

[0051] The rear display unit 450 displays information according to the signal from the memory control unit 422. The EVF 451 displays information according to the signal from the memory control unit 422 when an eyepiece is detected by the eyepiece detection unit 444. The analog signal generated by the imaging unit 411 is converted into a digital signal by the A / D converter 412 and recorded in the memory 421. The memory control unit 422 sequentially transfers the digital signal recorded in the memory 421 to the rear display unit 450 or the EVF 451. This enables real-time display, or live view shooting display.

[0052] The system control unit 420 switches the display (displayed) / hidden (hidden) of the rear display unit 450 and the EVF 451 according to the state detected by the eyepiece detection unit 444. When the eyepiece is not being used, the system control unit 420 displays the rear display unit 450 and hides the EVF 451. When the eyepiece is being used, the system control unit 420 displays the EVF 451 and hides the rear display unit 450.

[0053] The operation unit 460 is an input unit that receives operations from the user and consists of various operating components. The operation unit 460 includes various operating components (mode switching switch 461, shutter button 462, first shutter switch 463, second shutter switch 464, touch panel 465, power switch 466) which will be described later. The operation unit 460 is also an operating means for inputting various operation instructions to the system control unit 420.

[0054] The mode switch 461 switches the operating mode of the system control unit 420 to one of the following: still image shooting mode, video shooting mode, etc. Shooting modes included in still image shooting mode include auto shooting mode, auto scene detection mode, and manual shooting mode. Additionally, shooting modes included in still image shooting mode include aperture priority mode (Av mode), shutter speed priority mode (Tv mode), and program AE mode (P mode). Similarly, video shooting mode may also include multiple shooting modes.

[0055] The shutter button 462 is a button used by the photographer to give instructions for preparing to shoot and to take a picture. The first shutter switch 463 turns ON when the shutter button 462 on the digital camera 100 is half-pressed (instruction to prepare to shoot), generating the first shutter switch signal SW1. Signal SW1 initiates shooting preparation operations such as AF (autofocus), AE (automatic exposure), and AWB (auto white balance).

[0056] The second shutter switch 464 turns ON when the shutter button 462 is fully pressed (shooting instruction), generating the second shutter switch signal SW2. The system control unit 420, upon receiving the signal SW2, starts shooting operations such as reading the analog signal from the imaging unit 411, signal conversion processing in the A / D converter 412 and image processing unit 413, and writing the image data temporarily recorded in the memory 421 to the recording medium 600.

[0057] The touch panel 465 is a device that detects touch or drag operations by the photographer. Here, the touch panel 465 is integrated with the rear display unit 450, and can be operated by touching the display area of ​​the rear display unit 450 with a finger.

[0058] The power switch 466 is a switch that turns the power ON / OFF. The power control unit 431 controls the power supply from the power supply unit 430 based on the switching operation of the power switch 466.

[0059] The cooling fan 130 is controlled by the system control unit 420 to cool the heat source inside the digital camera 100.

[0060] The lens unit 500 is an interchangeable lens that can be attached to and detached from the digital camera 100. The lens 501 is a group of lenses that generate an optical image (subject image) from the subject light reflected from the subject, and is composed of multiple lenses, but in this diagram, for simplicity, only one lens is shown.

[0061] The lens communication terminal 506 is a communication terminal for the lens unit 500 to communicate with the digital camera 100. As mentioned above, the lens unit 500 can communicate with the system control unit 420, which controls the entire digital camera 100, by electrically connecting the lens communication terminal 506 and the communication terminal 440. This allows the system control unit 420 to communicate with the lens drive circuit 502, the lens system control circuit 505, and the aperture drive circuit 504 to control the position of the lens 501 and aperture 503, and to control the focus state of the real image by displacing the lens 501.

[0062] The recording medium 600 is a recording medium such as a memory card that is detachable from the digital camera 100 and is used to record captured images. Examples include SD cards, FLASH® memory, and hard disks.

[0063] As described above, the configuration of this embodiment makes it possible to provide an imaging device that can satisfy heat dissipation performance without hindering the movement of the image sensor.

[0064] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of its gist. [Explanation of Symbols]

[0065] 100 Digital cameras (imaging devices) 106 Image sensor section 115 Image sensor 114 Moving parts 113 Drive mechanism 130 Cooling fan (air blower)

Claims

[Claim 1] An image sensor unit comprising an image sensor, a movable part that supports the image sensor, and a drive mechanism that moves the movable part in a direction including a direction perpendicular to the optical axis, It has a blowing means, The blowing means is positioned outside the range of motion of the movable part when viewed from the optical axis direction, The imaging device is characterized in that the drive mechanism is not located between the blowing means and the movable part.

Images