JP2011010069A - Camera body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce temperature rise of a tripod mounting part of a camera body.SOLUTION: The camera body is provided with: an outer casing; a frame provided inside the outer casing; the tripod mounting part which is fixed to the frame and has a screw through hole; and a cover member which covers a second opening located on the side opposite to a first opening which is exposed to the outer surface of the outer casing and located on the side into which a screw for a tripod is inserted among openings on both ends of the screw through hole. The cover member has thermal conductivity lower than that of the tripod mounting part.

Description

  The present invention relates to a camera body such as a digital still camera that mainly performs still image shooting and a digital video camera that mainly performs moving image shooting. In particular, the present invention relates to a digital still camera, a digital video camera, or the like to which a tripod can be attached.

  Patent Document 1 discloses a single-lens reflex camera. This camera is a digital camera equipped with a CCD. This camera is an interchangeable lens type digital camera to which a lens unit can be attached and detached. This camera includes a mirror box device between the lens unit and the CCD. Then, the mirror box device guides the subject luminous flux from the lens unit to either the CCD or the prism. The subject light flux guided to the prism is guided to the viewfinder by the prism.

Japanese Patent Laid-Open No. 2007-127836

  Since conventional interchangeable lens type digital cameras have a mirror box device, it is difficult to reduce the size of the camera body. Accordingly, the inventors of the present application have devised a new interchangeable lens type digital camera that does not have a mirror box device. The inventors of the present application have found the following problems in further development of a new interchangeable lens type digital camera.

  By reducing the size and thickness of the camera body, the space around the image sensor and the board on which the body microcomputer that performs image processing is mounted has been reduced. As the value increases, the amount of heat generation increases and the heat generation density increases. In particular, since the tripod mounting portion is made of a metal material, it has a higher thermal conductivity than a resin often used as an exterior material. For this reason, the tripod mounting portion is easily affected by heat generated by the image sensor and the body microcomputer, and a rise in temperature becomes a problem. In particular, since the tripod mounting portion is exposed to the outside, it is easy to feel heat when the camera user touches it.

  An object of this invention is to provide the camera main body which suppressed the temperature rise of the tripod attachment part.

The above object is achieved by the following camera body.
Of the outer casing, a frame provided inside the outer casing, a tripod mounting portion that is fixed to the frame and has a threaded hole that passes therethrough, and the outer casing among openings at both ends of the threaded hole that penetrates. A cover member that covers a second opening that is exposed to the outer surface of the body and that is on the side opposite to the first opening that is an opening on the side where the tripod screw is inserted. The camera body has a lower thermal conductivity than the tripod mounting portion.

  ADVANTAGE OF THE INVENTION According to this invention, the camera main body which can reduce the temperature rise of a tripod attachment part can be provided.

Perspective view of camera system 1 A perspective view of the camera body 100 Block diagram of camera system 1 Schematic sectional view of camera system 1 Rear view of camera body 100 Comparative view of a single-lens camera from which a conventional single-lens reflex camera and a mirror box device are removed, (a) a schematic cross-sectional view of a conventional single-lens reflex camera, and (b) a schematic cross-sectional view of a single-lens camera from which a mirror box device is removed Schematic for demonstrating the structure of the tripod attachment part of 1st Embodiment, (a) Sectional drawing of a tripod attachment part, (b) Plan view of a tripod attachment part Schematic for explaining the structure of a conventional tripod mounting part, (a) a sectional view of the tripod mounting part, (b) a plan view of the tripod mounting part Schematic for demonstrating the structure of the tripod attachment part in 2nd Embodiment, (a) Sectional drawing of a tripod attachment part, (b) Plan view of a tripod attachment part

  A camera system having a camera body according to an embodiment of the present invention will be described. The following embodiment is an embodiment of the present invention, and the present invention is not limited to these embodiments.

<First Embodiment>
(1: Configuration)
(1-1: Overview of camera system)
FIG. 1 is a perspective view of a camera system 1 having a camera body according to the first embodiment of the present invention. The camera system 1 includes a camera body 100 and a lens unit 200 that can be attached to and detached from the camera body 100. FIG. 2 is a perspective view of the camera body 100. FIG. 3 is a functional block diagram of the camera system 1. The camera body 100 does not have a mirror box device. Therefore, the flange back can be reduced as compared with the conventional single-lens reflex camera. Moreover, the camera body is miniaturized by reducing the flange back. Furthermore, the lens unit 200 is downsized by reducing the flange back. Details of each part will be described below. For convenience of explanation, the subject side of the camera system 1 is referred to as the front, the imaging surface side is referred to as the back or the back, the vertical upper side in the normal posture of the camera system 1 is referred to as the upper side, and the vertical lower side is referred to as the lower side.

(1-2: Configuration of camera body)
FIG. 4 is a schematic sectional view of the camera system 1. FIG. 5 is a rear view of the camera body. The camera body 100 mainly includes a CMOS image sensor 110, a CMOS circuit board 113, a camera monitor 120, an operation unit 130, a main circuit board 142 including a camera controller 140, a body mount 150, a power supply 160, A card slot 170, an electronic viewfinder 180, a shutter unit 190, an optical low-pass filter 114, a diaphragm 115, a main frame 154, a tripod mounting portion 155, and a heat sink 195 are provided. The camera body 100 does not have a mirror box device. The camera body 100 includes, in order from the front, a body mount 150, a shutter unit 190, a diaphragm 115, an optical low-pass filter 114, a CMOS image sensor 110, a CMOS circuit board 113, a heat sink 195, a main circuit board 142, and a camera. A monitor 120 is arranged. The main frame 154 is disposed at a position overlapping the body mount 150 in the optical axis direction.

  The CMOS image sensor 110 captures an optical image of a subject incident through the lens unit 200 and generates image data. The generated image data is digitized by the AD converter 111. The image data digitized by the AD converter 111 is subjected to various image processing by the camera controller 140. Examples of the various image processing referred to here include gamma correction processing, white balance correction processing, scratch correction processing, YC conversion processing, electronic zoom processing, and JPEG compression processing. The function of the CMOS circuit board may be included in the CMOS image sensor or the main circuit board.

  The CMOS image sensor 110 operates at a timing controlled by the timing generator 112. The CMOS image sensor 110 performs a still image capturing operation, a moving image capturing operation, and the like. The moving image shooting operation includes a through image shooting operation. Here, the through image is an image in which data is not recorded on the memory card 171 after the moving image is captured. The through image is mainly a moving image, and is displayed on the camera monitor 120 and / or the electronic viewfinder 180 (hereinafter also referred to as EVF) in order to determine a composition for capturing a moving image or a still image. . The moving image capturing operation also includes a moving image recording operation. The moving image recording operation is an operation including a moving image shooting operation and an operation of recording moving image data in the memory card 171. The CMOS image sensor 110 can perform a low-resolution moving image shooting operation used as a through image and a high-resolution moving image shooting operation used for recording. As a high-resolution moving image, for example, a moving image of HD size (high vision size: 1920 × 1080 pixels) can be taken. The CMOS image sensor 110 is an example of an image sensor that captures an optical image of a subject and converts it into an electrical image signal. The image sensor is a concept including a CCD image sensor and the like.

  The CMOS circuit board 113 is a circuit board that drives and controls the CMOS image sensor 110. The CMOS circuit board 113 is a circuit board that performs predetermined processing on image data from the CMOS image sensor 110. The CMOS circuit board 113 includes a timing generator 112. The CMOS circuit board 113 includes an AD converter 111. The CMOS circuit board 113 is an example of an image sensor circuit board that drives and controls the image sensor and / or performs predetermined processing such as AD conversion on image data from the image sensor.

  The camera monitor 120 displays an image or the like indicated by the display image data. Display image data is created by the camera controller 140. The display image data is image data that has undergone image processing, data for displaying shooting conditions, operation menus, and the like of the camera system 1 as images. The camera monitor 120 can selectively display both moving images and still images. The camera monitor 120 has a liquid crystal display.

  The camera monitor 120 is provided in the camera body 100. In this embodiment, it is arranged on the back surface of the camera body 100, but it may be arranged anywhere on the camera body. The camera monitor 120 can change the angle of the display surface with respect to the camera body 100. Specifically, the camera body 100 has a hinge 121 between the camera body 100 and the camera monitor 120. The hinge 121 is disposed at the left end when viewed from the back of the camera body 100. Specifically, the hinge 121 has a first hinge and a second hinge. Specifically, the camera monitor 120 can rotate in the left-right direction around the first hinge. Further, it can also be rotated in the vertical direction around the second hinge.

  The camera monitor 120 is an example of a display unit provided in the camera body 100. In addition, as the display unit, an organic EL, inorganic EL, plasma display panel, or the like that can display an image can be used. Further, the display unit may be provided in another place such as a side surface or an upper surface instead of the back surface of the camera body 100.

  The electronic viewfinder 180 displays an image or the like indicated by the display image data created by the camera controller 140. The EVF 180 can selectively display both moving images and still images. Moreover, the EVF 180 and the camera monitor 120 may display the same content or display different content. These are controlled by the camera controller 140. The EVF 180 includes an EVF liquid crystal monitor 181 that displays an image and the like, an EVF optical system 182 that enlarges the display of the EVF liquid crystal monitor, and an eyepiece window 183 that allows the user to approach the eyes.

The EVF 180 is also an example of a display unit. The difference from the camera monitor 120 is that the user looks closer. The structural difference is that the EVF 180 has an eyepiece window 183, whereas the camera monitor 120 does not have an eyepiece window 183.
Note that the EVF liquid crystal monitor 181 ensures display luminance by providing a backlight (not shown) in the case of transmissive liquid crystal and a front light (not shown) in the case of reflective liquid crystal. The EVF liquid crystal monitor 181 is an example of an EVF monitor. The monitor for EVF can use what can display an image, such as organic EL, inorganic EL, and a plasma display panel. In the case of a self-luminous device such as an organic EL, an illumination light source is not necessary.

  The operation unit 130 receives an operation by a user. The operation unit 130 is operated by a user. The operation unit 130 includes a release button 131. The release button 131 accepts a shutter operation by the user. The operation unit 130 includes a power switch 132. The power switch 132 is a rotary dial switch provided on the upper surface of the camera body 100. The power is turned off at the first rotational position, and the power is turned on at the second rotational position. The operation unit only needs to accept an operation by the user, and includes a button, a lever, a dial, a touch panel, and the like.

  The camera controller 140 controls the entire camera body 100 including each part such as the CMOS image sensor 110. The camera controller 140 controls the shutter unit 190 so that the shutter unit 190 maintains an open state in a state where the supply of power from the power source 160 is stopped. In addition, the camera controller 140 receives an instruction from the operation unit 130. The camera controller 140 transmits a signal for controlling the lens unit 200 to the lens controller 240 via the body mount 150 and the lens mount 250. And each part of the lens unit 200 is controlled indirectly. That is, the camera controller 140 controls the entire camera system 1. The camera controller 140 receives various signals from the lens controller 240 via the body mount 150 and the lens mount 250. The camera controller 140 uses the DRAM 141 as a work memory during control operations and image processing operations. The camera controller 140 is an example of a body control unit. The camera controller 140 is disposed on the main circuit board 142.

  The card slot 170 can be loaded with a memory card 171. The card slot 170 controls the memory card 171 based on the control from the camera controller 140. Specifically, the card slot 170 stores image data in the memory card 171. The card slot 170 outputs image data from the memory card 171. In addition, moving image data is stored in the memory card 171. The card slot 170 outputs moving image data from the memory card 171.

  The memory card 171 can store image data generated by the camera controller 140 through image processing. For example, the memory card 171 can store an uncompressed RAW image file, a compressed JPEG image file, and the like. The memory card 171 can output image data or an image file stored therein. The image data or image file output from the memory card 171 is subjected to image processing by the camera controller 140. For example, the camera controller 140 generates display image data by decompressing image data or an image file acquired from the memory card 171.

  The memory card 171 can further store moving image data generated by the camera controller 140 through image processing. For example, the memory card 171 is a video compression standard H.264. A moving image file compressed according to H.264 / AVC can be stored. The memory card 171 can output moving image data or a moving image file stored therein. The moving image data or moving image file output from the memory card 171 is subjected to image processing by the camera controller 140. For example, the camera controller 140 expands the moving image data or moving image file acquired from the memory card 171 to generate display moving image data. The memory card 171 is an example of a storage unit. The storage unit may be detachable from the camera body 100 like the memory card 171 or may be fixed to the camera system 100.

  The power supply 160 supplies power for use in the camera system 1. The power source 160 may be, for example, a dry battery or a rechargeable battery. Moreover, the power supplied from the outside by a power cord or the like may be supplied to the camera system 1.

  The body mount 150 holds the detachable lens unit 200. The body mount 150 can be mechanically and electrically connected to the lens mount 250 of the lens unit 200. Data and / or control signals can be transmitted and received between the camera body 100 and the lens unit 200 via the body mount 150 and the lens mount 250. Specifically, the body mount 150 and the lens mount 250 transmit and receive data and / or control signals between the camera controller 140 and the lens controller 240. The body mount 150 supplies the power received from the power supply 160 to the entire lens unit 200 via the lens mount 250.

  Specifically, the body mount 150 includes a body mount ring 151 and a body mount contact support portion 152. The body mount ring 151 is either in a state of being fitted to the lens mount ring 251 or not in a state of being fitted, depending on a rotational positional relationship around the optical axis with the lens mount ring 251 of the lens unit 200. That is, when the rotational positional relationship between the body mount ring 151 and the lens mount ring 251 is in the first state, the lens mount ring 251 is fitted into the body mount ring 151, and the lens mount ring 251 is the body. It is movable in the optical axis direction with respect to the mount ring 151. Further, when the lens mount ring 251 is inserted into the body mount ring 151 in the first state and the lens mount ring 251 is rotated with respect to the body mount ring 151, the lens mount ring 251 is fitted into the body mount ring 151. The rotational positional relationship between the body mount ring 151 and the lens mount ring 251 at this time is the second state. When the rotational positional relationship is in the second state, the body mount ring 151 mechanically holds the lens unit 200. Therefore, the body mount ring 151 is required to have strength. The body mount ring 151 is preferably made of metal. In the present embodiment, the body mount ring 151 is made of metal. The body mount ring 151 is connected to the body mount contact support portion 152 and supported by the body mount contact support portion 152. The body mount contact support portion 152 has a plurality of electrical contacts 153. The electrical contacts 153 are electrically connected to the electrical contacts 253 included in the lens mount 250, respectively. The body mount 150 and the lens mount 250 can be electrically connected by the electrical contact 153 of the body mount 150 and the electrical contact 253 of the lens mount 250. In addition, power, data and / or control signals are transmitted and received by the electrical contact 153 of the body mount 150 and the electrical contact 253 of the lens mount 250. The body mount contact support portion 152 is disposed between the body mount ring 151 and the shutter unit 190. The body mount contact support portion 152 has an opening. The diameter of the opening is smaller than the inner diameter of the body mount ring. The body mount contact support portion 152 is an example of a protective member that protects the lens unit 200 from entering the camera body 100.

  The shutter unit 190 is a so-called focal plane shutter. The shutter unit 190 is disposed between the body mount 150 and the CMOS image sensor 110. The shutter unit 190 has a rear curtain, a front curtain, and a shutter support frame. The shutter support frame has an opening. When the rear curtain and the front curtain advance and retract to the opening, light is guided to the CMOS image sensor 110 through the opening, or light to the CMOS image sensor 110 is blocked. The shutter unit 190 can be mechanically kept open. Mechanically holding is a concept of holding an open state without using electric force. For example, the object is engaged with the object, or is held by a permanent magnet.

  The optical low-pass filter 114 removes high-frequency components of the subject light. Specifically, the optical low-pass filter 114 separates the subject image formed by the lens unit 200 so that the resolution is coarser than the pixel pitch of the CMOS image sensor 110. In general, in an image sensor such as a CMOS image sensor, an RGB color filter called a Bayer array and a YCM complementary color filter are arranged in each pixel. Therefore, when the image is resolved to one pixel, not only a false color is generated, but also an ugly moire phenomenon occurs in a subject having a repetitive pattern. Further, the optical low-pass filter 114 has an Ir cut filter function for cutting infrared light.

  The diaphragm 115 is disposed in front of the CMOS image sensor 110 and prevents dust from adhering to the CMOS image sensor 110. Further, dust attached to the diaphragm 115 itself is shaken off by vibration. Specifically, the diaphragm 115 has a configuration in which a transparent thin plate-like member is fixed to another member via a piezoelectric element. And an alternating voltage is applied to a piezoelectric element, a piezoelectric element is vibrated, and a plate-shaped member is vibrated. The diaphragm support unit 116 supports the diaphragm 115 so as to be fixed at a predetermined position with respect to the CMOS image sensor 110.

  The main frame is provided inside an external housing that constitutes the exterior of the camera body 100. The main frame 154 is arranged from the front surface to the lower surface inside the camera body. The main frame 154 is fitted with the body mount contact support portion 152 of the body mount 150 and supports the lens unit 200 via the body mount 150. Therefore, the main frame 154 needs to be strong. Therefore, the main frame 154 is preferably made of metal. In the present embodiment, the main frame 154 is made of metal.

  The tripod attachment part 155 has a threaded hole that penetrates the tripod. The tripod mounting portion 155 is fitted with the main frame 154. In the screw hole, one opening (first opening) on the side where the tripod screw is inserted is exposed on the lower surface of the camera body. A tripod can be attached to the tripod attachment portion 155 and supports the camera body. When a tripod is attached to the tripod attachment portion 155, the tripod attachment portion needs to be as strong as possible so that the thread of the tripod attachment portion 155 is not damaged. Therefore, it is preferable that the tripod mounting portion 155 is made of metal. On the other hand, in order to reduce heat transfer to the tripod attachment part 155, the tripod attachment part is preferably made of resin. In the present embodiment, the tripod mounting portion 155 is made of metal. And the tripod attachment part 155 is covered with the 2nd opening part opposite to a 1st opening part with the cover member 156 formed with resin. Details of the configuration of the tripod mounting portion 155 will be described later.

  The heat sink 195 is disposed between the CMOS image sensor 110 and the main circuit board 142. Specifically, the heat sink 195 is disposed between the CMOS circuit board 113 and the main circuit board 142. The heat radiating plate 195 is for radiating the heat generated by the CMOS image sensor 110. When a metal such as aluminum or copper is used as a material, a preferable heat transfer characteristic can be obtained.

  A heat conducting unit 196 is connected to the heat radiating plate 195 in order to transmit heat to the diaphragm support unit 116. The heat conducting unit 196 is connected and fixed to the diaphragm support unit 116. The heat generated by the CMOS image sensor 110 is transmitted to the diaphragm support unit 116 through the heat radiating plate 195 and the heat conducting unit 196. That is, a heat radiating plate 195 is disposed on the back surface of the CMOS image sensor 110, and a heat conducting portion 196 is disposed from the heat radiating plate 195 to the diaphragm support portion 116 disposed on the front surface of the CMOS image sensor 110. Further, four heat conducting portions 196 extend from the top, bottom, left, and right of the heat sink 195, and the CMOS image sensor 110 is covered by the four heat conducting portions 196. As described above, the CMOS image sensor 110 is surrounded by the heat sink 195 and the four heat conduction portions 196 extending from the heat sink 195 in the five directions, ie, the top, bottom, left, and right, excluding the front side.

  The heat conducting unit 196 is not necessarily connected to the diaphragm support unit 116, but may be connected to any component disposed between the main frame 154 and the CMOS image sensor 110. Examples include a body mount contact holding part 152 and a shutter unit 190.

  The connection destination of the heat conducting unit 196 is not necessarily 4 points. Although it is desirable that three or more points are connected, it is sufficient to connect and fix at least one.

(1-3: Configuration of lens unit)
The lens unit 200 includes an optical system, a lens controller 240, a lens mount 250, a diaphragm unit 260, and a lens barrel 290. The optical system of the lens unit 200 includes a zoom lens 210, an OIS lens 220, and a focus lens 230. The optical system is housed inside the lens tube 290. Further, a zoom ring 213, a focus ring 234, and an OIS switch 224 are provided outside the lens tube.

  The zoom lens 210 is a lens for changing a magnification of an optical image of a subject (hereinafter also referred to as a subject image) formed by the optical system of the lens unit 200, that is, a focal length of the optical system. The zoom lens 210 is composed of one or a plurality of lenses. The zoom lens 210 includes a first lens group L1 and a second lens group L2 of the optical system. The zoom lens 210 changes the focal length by moving in a direction parallel to the optical axis AX201 of the optical system.

  The zoom ring 213 is a cylindrical member and can be rotated on the outer peripheral surface of the lens cylinder 290. The zoom ring 213 is an example of a zoom operation unit that operates a focal length, and is an example of a zoom operation unit in which a focal length is determined according to a position after the operation.

  When the zoom ring 213 is operated by the user, the drive mechanism 211 transmits the operation to the zoom lens 210 and moves the zoom lens 210 along the optical axis AX direction of the optical system. As an example, the drive mechanism 211 has a cam mechanism, and converts the rotation operation of the zoom ring 213 into the straight movement operation of the zoom lens 210. The driving mechanism 211 is an example of a zoom lens driving unit.

  The detector 212 detects the drive amount in the drive mechanism 211. The lens controller 240 and / or the camera controller 140 can grasp the focal length in the optical system by acquiring the detection result in the detector 212. Further, the lens controller 240 and / or the camera controller 140 obtains the detection result of the detector 212, thereby grasping the position of the zoom lens (L1, L2, etc.) in the lens unit 200 in the optical axis AX direction. be able to. The drive mechanism 211 only needs to be able to move the zoom lens 210 along the optical axis AX direction. For example, the driving mechanism 211 transmits the driving force from the driving force generation unit such as a motor to the zoom lens 210 according to the rotation position of the operation unit such as the zoom ring 213, and the light corresponding to the rotation position of the zoom ring 213. It may be moved to a position in the axis AX direction.

  The OIS lens 220 is a lens for correcting blurring of a subject image formed by the optical system of the lens unit 200. Specifically, the OIS lens 220 corrects the blur of the subject image caused by the camera system 1 blur. The OIS lens 220 moves in a direction that cancels out the camera system 1 blur, thereby reducing the relative blur between the CMOS image sensor 110 and the subject image. Specifically, the OIS lens 220 moves in a direction that cancels out the blur of the camera system 1, thereby reducing the blur of the subject image on the CMOS image sensor 110. The OIS lens 220 is composed of one or a plurality of lenses. The actuator 221 drives the OIS lens 220 in a plane perpendicular to the optical axis AX of the optical system under the control of the OIS IC 223.

  The actuator 221 can be realized by a magnet and a flat coil, for example. The position detection sensor 222 is a sensor that detects the position of the OIS lens 220 in a plane perpendicular to the optical axis AX of the optical system. The position detection sensor 222 can be realized by a magnet and a Hall element, for example. The OIS IC 223 controls the actuator 221 based on the detection result of the position detection sensor 222 and the detection result of a shake detector such as a gyro sensor. The OIS IC 223 obtains the detection result of the shake detector from the lens controller 240. Further, the OIS IC 223 transmits a signal indicating the state of the optical image blur correction process to the lens controller 240.

  The OIS lens 220 is an example of a shake correction unit. As a means for correcting the blur of the subject image caused by the camera system 1 blur, an electronic blur correction that generates image data corrected based on the image data from the CMOS image sensor 110 may be applied. The CMOS image sensor 110 is driven in a vertical plane parallel to the optical axis AX of the optical system as means for reducing the relative blur between the CMOS image sensor 110 and the subject image caused by the camera system 1 shake. It is good.

  The OIS switch 224 is an example of an operation unit for operating the OIS. When the OIS switch 224 is turned off, the OIS lens 220 does not operate. When the OIS switch 224 is turned on, the OIS lens 220 becomes operable.

  The focus lens 230 is a lens for changing the focus state of the subject image formed on the CMOS image sensor 110 by the optical system. The focus lens 230 is composed of one or a plurality of lenses. The focus lens 230 changes the focus state of the subject image by moving in a direction parallel to the optical axis AX of the optical system.

  The focus motor 233 drives the focus lens 230 to advance and retract along the optical axis AX of the optical system based on the control of the lens controller 240. Thereby, the focus state of the subject image formed on the CMOS image sensor 110 by the optical system can be changed. The focus motor 233 can drive the focus lens 230 independently of the drive of the zoom lens 210. Specifically, the focus motor 233 drives the focus lens 230 in the optical axis AX direction with reference to the second lens group L2. In other words, the focus motor 233 can change the relative distance between the second lens unit L2 and the focus lens 230 in the optical axis AX direction. The focus lens 230 and the focus motor 233 move in the optical axis AX direction together with the second lens group L2. Accordingly, when the second lens unit L2 moves in the optical axis AX direction by the zoom operation, the focus lens 230 and the focus motor 233 also move in the optical axis AX direction. Even when the second lens group L2 is stationary in the optical axis AX direction, the focus motor 233 can drive the focus lens 230 in the optical axis AX direction with reference to the second lens group L2. The focus motor 233 can be realized by a DC motor, a stepping motor, a servo motor, an ultrasonic motor, or the like. The focus motor 233 is an example of a focus lens driving unit.

  The relative position detector 231 and the origin position detector 232 are encoders that generate signals indicating the driving state of the focus lens 230. The relative position detector 231 includes a magnetic scale and a magnetic sensor, detects a change in magnetism, and outputs a signal corresponding to the change in magnetism. The magnetic sensor is, for example, an MR sensor. The origin position detector 232 is an origin detector that detects the origin position of the focus lens 230 with respect to the second lens group L2. The origin position detector 232 is a photo sensor, for example. The lens controller 240 recognizes that the focus lens 230 is at the origin based on a signal from the origin position detector 232. At this time, the lens controller 240 sets the value of the counter 243 provided therein. The counter 243 counts the extreme value of the magnetic change based on the signal output from the relative position detector 231. When the extreme value of the magnetic change is detected when the focus lens 230 is moved in the first direction parallel to the optical axis AX, the count is incremented by “+1”. When the extreme value of the magnetic change is detected when the focus lens 230 is moved in the second direction opposite to the first direction parallel to the optical axis AX, the count is set to “−1”. In this way, the lens controller 240 can grasp the position of the focus lens 230 in the optical axis AX direction with respect to the second lens group L2 by detecting the relative position from the origin position which is an absolute position. Further, as described above, the lens controller 240 can grasp the position in the optical axis AX direction within the lens unit 200 of the second lens group L2. Therefore, the lens controller 240 can grasp the position of the focus lens 230 in the optical axis AX direction within the lens unit 200. The relative position detector 231 and the origin position detector 232 are examples of focus lens position detection means. The focus lens position detection unit may directly detect the position of the focus lens, or may detect the position of a mechanism member that is linked to the focus lens.

  The aperture unit 260 is a light amount adjusting member that adjusts the amount of light that passes through the optical system. The aperture unit 260 includes an aperture blade that can block a part of the light beam that passes through the optical system, and an aperture drive unit that drives the aperture blade and changes the shielding amount to adjust the amount of light. The camera controller 140 determines the aperture unit 260 based on the amount of light received by the CMOS image sensor 110, whether still image shooting or movie shooting is performed, an operation in which an aperture value is preferentially set, and the like. Instruct the operation.

  The lens controller 240 controls the entire lens unit 200 such as the OIS IC 223 and the focus motor 233 based on the control signal from the camera controller 140. In addition, signals are received from the detector 212, the OIS IC 223, the relative position detector 231, the origin position detector 232, and the like, and transmitted to the camera controller 140. The lens controller 240 performs transmission / reception with the camera controller 140 via the lens mount 250 and the body mount 150. The lens controller 240 uses the DRAM 241 as a work memory during control. The flash memory 242 stores a program and parameters used when the lens controller 240 is controlled.

(1-4: structural features)
The camera body 100 does not have a mirror box device. Then, the flange back can be shortened, and the camera body 100 can be reduced in size and thickness. Furthermore, since the flange back is short, the design margin of the optical system is increased, and the lens unit 200 can be downsized. Therefore, the camera system 1 can be downsized. However, new problems have also been revealed. Specifically, as the camera body 100 is reduced in size and thickness, the space for housing the main circuit board 142 including the CMOS image sensor 110 and the camera controller 140 is reduced, so that the heat generation density is increased. In addition, the amount of heat generated by the CMOS image sensor 110 and the camera controller 140 has increased due to the increased power consumption of the CMOS image sensor 110 and the camera controller 140 as a result of higher image quality and video shooting support. Thereby, the temperature of the CMOS image sensor 110 and the camera controller 140 increases, and accordingly, the temperature of the position of the tripod mounting portion 155 disposed under the CMOS image sensor 110 and the camera controller 140 is likely to increase. In other words, with the conventional tripod mounting portion structure, there is a possibility that the user of the camera may feel hot when touching the tripod mounting portion.

  Hereinafter, the problem will be described in more detail with reference to the drawings.

  FIG. 6 is a schematic cross-sectional comparison diagram of a camera system 9 configured by deleting the mirror box device from the single-lens reflex camera 800 having the mirror box device and the conventional single-lens reflex camera 800, and FIG. FIG. 2B is a schematic cross-sectional view of a reflex camera 800, and FIG. 4B is a schematic cross-sectional view of a camera system 9 that is an example in which the mirror box device is omitted from the conventional single-lens reflex camera 800.

  In the conventional single-lens reflex camera 800, a CMOS circuit board 813 is disposed on the back surface of the CMOS image sensor 810. In addition, a main circuit board 842 including a camera controller 840 is disposed on the back surface of the CMOS circuit board 813. Further, in order to ensure the strength of the camera body 801, a metal main frame 854 is disposed along the bottom surface from the front surface inside the camera body 801.

  The mirror box device includes a reflection mirror 803 and a pentaprism 804. The reflection mirror 803 and the pentaprism 804 guide the optical image of the subject incident through the lens unit 802 to the CMOS image sensor 810 or the viewfinder 805. A single-lens reflex camera 800 having a mirror box device requires a space for disposing a movable reflection mirror 803 and a pentaprism 804 inside the camera body 801. In addition, it is necessary to secure a space on the optical path from the reflection mirror 803 to the optical viewfinder 805. Therefore, the camera body 801 is not suitable for downsizing. However, the camera body 801 has a large space, the camera body 801 has a large surface area, the distance between the CMOS image sensor 810 and the main circuit board 842 can be secured, and the tripod mounting portion 855 is provided with the CMOS image sensor 810 and the main circuit. It is easy to dissipate the heat generated from the CMOS image sensor 810 due to reasons such as not being disposed directly under the substrate 842. Further, it is difficult to conduct heat to the main circuit board 842. Furthermore, it is difficult for heat to be conducted to the tripod mounting portion 855.

  On the other hand, the camera system 9 of FIG. 6B does not have a mirror box device. Therefore, the camera body 900 can be reduced in size. That is, the space formed by the movable reflecting mirror or the like as in the prior art is eliminated or reduced. As a result, the heat generation density is increased.

  Further, it is assumed that the camera system 9 uses a CMOS image sensor 910 that supports shooting of high-resolution moving images. In this case, the power consumption increases approximately three times (0.4 W to 1.2 W) compared to the conventional CMOS image sensor. That is, the amount of heat generated in the CMOS image sensor 910 is increased compared to the conventional one. As for still image shooting, it is expected that the resolution will be further increased in the future, and accordingly, the power consumption and the heat generation amount of the CMOS image sensor are expected to increase.

  As described above, the camera system 9 with the mirror box device removed has the following problems as compared with the conventional single-lens reflex camera 800. The first is that the amount of heat generation increases, and the second is that the tripod mounting portion 955 and the CMOS image sensor 910 that is a heating element approach each other with downsizing. As a result, in the camera system 9, when a tripod mounting portion having a conventional structure is used, the temperature of the tripod mounting portion increases. Then, when the camera user touches the tripod mounting part, it may feel hot.

  Therefore, in the camera system 1 of the present embodiment, the tripod mounting portion 155 disposed below the CMOS image sensor 110 has a threaded hole that passes therethrough. An opening (second opening) on the inner side of the camera body in the threaded hole that penetrates is covered with a cover member 156. The cover member 156 positioned on the CMOS image sensor 110 side of the tripod attachment portion 155 is made of a heat conductive material that is lower than the tripod attachment portion 155. The tripod attachment 155 that exposes the first opening on the lower surface side of the camera body 100 is made of metal. The heat of the CMOS image sensor 110 or the main circuit board 142 is transmitted to the cover member 156 by radiant heat or convection. However, since the cover member 156 is made of a low thermal conductivity material, heat is not easily transmitted to the tripod mounting portion 155 as compared to the case where the cover member 156 is made of metal. Therefore, the temperature rise of the tripod attachment part 155 is reduced. Moreover, the tripod attachment part 155 has a threaded hole therethrough. Therefore, compared to a conventional screw hole configuration that does not penetrate, the configuration is less susceptible to heat from heat sources such as the CMOS image sensor 110 and the main circuit board 142. As a result, the possibility that the camera user feels hot when touching the exposed surface 158 of the tripod attachment 155 can be reduced.

  Hereinafter, the structure in the vicinity of the tripod mounting portion of the present embodiment will be described more specifically. 7A and 7B are schematic views for explaining the structure of the tripod mounting portion 155 and the cover member 156, where FIG. 7A is a cross-sectional view, and FIG.

  FIG. 8 shows a tripod mounting portion having a conventional structure. In the tripod mounting portion 755 having a conventional structure, the temperature has increased due to radiant heat and convection from the CMOS image sensor 110. Therefore, in the structure in this embodiment, in order to increase the distance between the CMOS image sensor 110 and the tripod mounting portion 155, a structure having a threaded hole, that is, a hollow tripod mounting portion 155 is used. In the tripod mounting portion 155 having a hollow structure, dust or the like may enter the camera body from the outside. Therefore, the upper surface of the tripod mounting portion 155 is covered with the cover member 156 made of a low thermal conductivity material and fixed to the main frame 154. By doing so, the danger of dust and the like entering was prevented. The cover member 156 receives the radiant heat from the CMOS image sensor 110 and rises in temperature. However, since the cover member 156 is a low thermal conductivity material, it is difficult for heat to be transmitted to the tripod mounting portion 155. For this reason, the temperature of the tripod mounting portion 155 does not increase as compared with the tripod mounting portion 755 having the conventional structure.

  In the structure of the present embodiment, the cover member 156 is fixed to the main frame 154, but it is not necessarily fixed to the main frame 154. It is sufficient if it is fixed to any part of the camera body. Specifically, an external housing of the camera body 100 can be used. The low thermal conductivity material specifically means a material having lower thermal conductivity than the metal tripod mounting portion 155. More specifically, polycarbonate resin and the like can be mentioned.

  In this embodiment, the strength of the camera body 100 is ensured by the main frame 154, but the main frame 154 is not necessarily a necessary part. This is not necessary if a predetermined strength is secured by the external housing of the camera body 100. In this case, the cover member 156 may be attached to the external housing of the camera body 100. Attaching the cover member 156 to the main frame 154 or the external housing is also effective in terms of transferring heat and diffusing. As a result, the heat transmitted to the tripod mounting portion 155 can be further reduced. Furthermore, in this case, it is preferable that the tripod mounting portion 155 has a lower thermal conductivity than the main frame 154 and the external housing. This is because a large amount of heat from the cover member 156 is transmitted to the main frame 154 and the external housing side, so that heat can be reduced more effectively.

Second Embodiment
Next, a second embodiment of the present invention will be described. The second embodiment differs from the camera main body 100 of the first embodiment only in the structure near the tripod mounting portion. Therefore, only the structure near the tripod mounting portion will be described, and the description of the common portion will be omitted.
FIG. 9 is a cross-sectional view and a top view of the tripod mounting portion 455 and the cover member 456 in the second embodiment. In the second embodiment, the cover member 456 is not fixed to the main frame 154, but is only fixed to the upper side (second opening side) of the tripod mounting portion 455.

  The heat generated in the COMOS image sensor 110 or the main board circuit 142 is transmitted to the cover member 456 before being transmitted to the tripod mounting portion 455. The cover member 456 is made of a low thermal conductivity material, and is less likely to transfer heat compared to a tripod mounting portion 455 made of a high thermal conductivity material such as metal. Therefore, heat transfer to the tripod attachment part 455 is hindered, and the temperature rise of the tripod attachment part 455 is reduced. That is, the temperature rise of the tripod attachment exposed surface 458 that the camera user touches is reduced.

  Also, the cover member 456 covers the upper surface side opening (second opening) of the tripod mounting portion 455, thereby preventing dust and the like from entering the camera body from the outside through the tripod mounting portion 455 having a hollow structure. It also has an effect.

  The present invention can be applied to a camera system to which a tripod can be attached. Specifically, it can be applied to a digital still camera, a digital video camera, and the like.

DESCRIPTION OF SYMBOLS 1 Camera system 100 Camera body 110 CMOS image sensor 111 AD converter 112 Timing generator 113 CMOS circuit board 114 Optical low pass filter 115 Diaphragm 116 Diaphragm support part 117 Mark 120 Camera monitor 121 Hinge 130 Operation part 131 Release button 132 Power switch 140 Camera controller 141 DRAM
142 Main Circuit Board 150 Body Mount 151 Body Mount Ring 152 Body Mount Contact Support 153 Electrical Contact 154 Main Frame 155 Tripod Mount 156 Cover Member 158 Tripod Mount Exposed Surface 160 Power Supply 170 Card Slot 171 Memory Card 180 Electronic Viewfinder 181 EVF LCD monitor 182 EVF optical system 183 Eyepiece window 190 Shutter unit 191 Rear curtain 192 Front curtain 193 Shutter support frame 195 Heat sink 196 Heat conduction part 197 Fastening part 200 Lens unit 201 Optical axis AX
210 Zoom lens 211 Drive mechanism 212 Detector 213 Zoom ring 220 OIS lens 221 Actuator 222 Position detection sensor 223 OIS IC
224 OIS switch 230 Focus lens 231 Relative position detector 232 Origin position detector 233 Focus motor 234 Focus ring 240 Lens controller 241 DRAM
242 Flash memory 243 Counter 250 Lens mount 251 Lens mount ring 253 Electrical contact 260 Unit 290 Lens tube 455 Tripod mount 456 Cover member 458 Tripod mount exposed surface 755 Tripod mount exposed surface 758 Tripod mount exposed surface 800 Single lens reflex Camera 801 Single-lens reflex camera body 802 Lens unit 803 Reflective mirror 804 Penta prism 805 Optical viewfinder 810 CMOS image sensor 813 CMOS circuit board 840 Camera controller 842 Main circuit board 854 Main frame 855 Tripod attachment 9 Single-lens camera with the mirror box device removed System 900 Single-lens camera body without the mirror box device 910 CMOS image sensor 9 3 CMOS circuit board 940 the camera controller 942 the main circuit board 954 mainframe 955 tripod mounting part 958 tripod mounting part exposed surface 980 electronic viewfinder

Claims (4)

An external enclosure,
A frame provided inside the external housing;
A tripod mounting portion fixed to the frame and having a threaded hole therethrough;
Of the openings at both ends of the threaded hole, the second is located on the opposite side of the first opening which is the opening on the side where the tripod screw is inserted and exposed to the outer surface of the external housing. A cover member covering the opening of
The cover member has a lower thermal conductivity than the tripod mounting portion,
The camera body. The cover member is fixed to the frame;
The camera body according to claim 1. The cover member is fixed to the external housing,
The camera body according to claim 1. The tripod mounting portion has a lower thermal conductivity than the frame,
The camera body according to claim 2.

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