JP2006267793A - Lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens unit where an imaging device and a package board are efficiently cooled and also which is miniaturized. <P>SOLUTION: The lens barrel 4 is provided with a focus lens unit 28 and a partition plate 40 inside. The inside of the lens barrel 4 is divided into 1st space 43, 2nd space 44 and 3rd space 45. A lens barrel main body 20 is provided with a 1st path 46 through which the 1st space 43 communicates with the 2nd space 44, and a 2nd path 47 through which the 2nd space 44 communicates with the 3rd space 45. The flow of air is generated in the 2nd space 44 with the movement of the focus lens unit 28, so that a CCD 25 is cooled. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens barrel that incorporates an image sensor and is detachable from a camera body.

  2. Description of the Related Art Digital cameras that convert a captured image captured using an image sensor such as a CCD into digital image data and record it on a recording medium such as a built-in memory or a memory card have become widespread. Among digital cameras, there are interchangeable lens types in which various lenses are exchanged to perform photographing according to preference. An interchangeable-lens digital camera is composed of a camera body and a lens barrel, and generally has an image sensor built in the camera body. In this case, when the lens barrel is mounted, it is necessary to optically connect the image pickup element of the camera body and the lens group of the lens barrel. Had a problem that it was difficult to handle.

  In order to facilitate the handling of an interchangeable lens type digital camera, there has been known one that incorporates an image sensor on the lens barrel side. In this case, since it is not necessary to optically connect the camera body and the lens barrel, it is only necessary to electrically connect them, so that anyone can easily attach the lens barrel. In addition, the type with a built-in image sensor on the camera body side has a problem that dust enters the camera body and adheres to the image sensor. However, the type with a built-in image sensor on the lens barrel side has a problem. The above problem can be solved by making the lens barrel have a sealed structure. However, in the type in which the imaging element is built in the lens barrel side, the imaging element and a circuit for driving the imaging element are arranged in a narrow space in the lens barrel. This adversely affects the performance of each part. In particular, when a circuit for processing an output signal from the image sensor is disposed, heat sources are densely packed and cooling efficiency becomes worse. For this reason, it is necessary to efficiently cool the image pickup device and the mounting substrate arranged in the lens barrel.

Conventionally, a technique for cooling a portion that generates heat in the apparatus has been proposed. Patent Document 1 describes a laser device that excites a solid-state laser element with semiconductor laser light, and a heat radiating fin is provided in the device body. Patent Document 2 describes a camera in which a lens barrel is protruded, and a heat generating component is disposed on the side of the lens barrel, and a heat radiating plate is attached to the heat generating component. Patent Document 3 describes an endoscope external television camera that can be attached to and detached from an endoscope, and a blower mechanism is provided on the back side of a solid-state imaging device that generates heat.
JP-A-8-167751 JP 2002-112082 A JP-A-5-34605

  However, in the techniques described in Patent Document 1 and Patent Document 2, only the radiation fins and the heat radiation plate are attached, and the air flow is not actively generated, so that the cooling efficiency is not sufficiently increased. . In Patent Document 3, a blower mechanism is provided only for cooling the solid-state imaging device. However, a space for installing the blower mechanism in the apparatus must be secured, and the apparatus becomes large.

  An object of the present invention is to provide a lens barrel capable of efficiently cooling a built-in image sensor and miniaturizing the lens barrel.

  The present invention relates to a lens barrel having a built-in image sensor and detachable from a camera body, a movable lens unit movable in an optical axis direction, and holding the image sensor behind the movable lens unit and moving the lens A partition plate that partitions the space between the lens unit and the rear wall portion of the barrel main body substantially perpendicular to the optical axis, a first space between the moving lens unit and the partition plate, and the partition plate A first passage that communicates the second space with the rear wall portion, and an air flow is generated in the second space through the first passage as the movable lens unit moves. And

  It is preferable to include a fixed lens disposed in front of the moving lens unit, a third space between the fixed lens and the moving lens unit, and a second passage that communicates the second space. The first and second passages are preferably formed inside the lens barrel body. The first passage may be a vent hole formed in the partition plate, and the second passage may be a heat radiating pipe spirally wound around the outer peripheral surface of the lens barrel body and having an end connected to each space. .

  It is preferable that a second passage for communicating the space outside the lens barrel and the second space is provided. Preferably, the first passage is a vent hole formed in the partition plate, and the second passage is a vent hole formed in the lens barrel body.

  In the second space, a mounting board on which a circuit for processing an output signal from the imaging element is mounted is provided so as to be located behind the imaging element, and the rear surface of the imaging element and the mounting board It is preferable that a radiation fin that contacts the front surface is provided.

  According to the lens barrel of the present invention, the movable lens unit that is movable in the optical axis direction, the image pickup element is held behind the movable lens unit, and the movable lens unit is disposed between the movable lens unit and the rear wall portion of the barrel main body. A partition plate that partitions the space substantially perpendicular to the optical axis, and a first passage that communicates the first space between the moving lens unit and the partition plate and the second space between the partition plate and the rear wall portion. Since the air flow is generated in the second space through the first passage as the moving lens unit moves, the air flow is generated behind the image sensor to disperse the heat of the image sensor, It can be cooled efficiently. Further, since the moving lens unit can be used as a drive source that generates an air flow in the second space, it is not necessary to provide a new drive source, and the increase in size of the lens barrel can be suppressed.

  Since the fixed lens is disposed in front of the moving lens unit, and the second path that communicates the third space and the second space between the fixed lens and the moving lens unit is provided, when the moving lens unit moves backward, When the air flows into the second space through the first passage and the air flows out of the second space through the second passage, and the moving lens unit moves in the forward direction, the second space passes through the second passage. Air flows into the space and flows out of the second space through the first passage. Thereby, the flow of air in the second space becomes smooth, and the cooling efficiency increases.

  In the case where the first and second passages are formed inside the barrel main body, heat is released to the outside of the barrel when the heated air passes through each passage, so that the cooling efficiency is improved. Further, the cooling mechanism is not exposed to the outside, and the lens barrel can be made excellent in design.

  In the case where the second passage is a heat radiating pipe, heat is released from the heat radiating pipe to the outside when the heated air passes through the heat radiating pipe, so that the cooling efficiency is further improved.

  When the second passage for communicating the space outside the lens barrel and the second space is provided, since the heated air is directly discharged to the outside of the lens barrel, the cooling efficiency is further improved.

  When a mounting board on which a circuit for processing an output signal from the image sensor is mounted is provided in the second space so as to be positioned behind the image sensor, and a heat radiation fin that contacts the rear surface of the image sensor and the front surface of the mounting board is provided. Since the heat of the image pickup device and the mounting substrate is efficiently transferred to the air in the second space through the heat radiation fin, the image pickup device and the mounting substrate are cooled more efficiently. By providing a mounting board on which a circuit for processing the output signal from the image sensor is mounted in the lens barrel, the amount of data sent from the lens barrel to the camera body is reduced. Communication time can be reduced. By covering the vent hole with a moisture permeable and waterproof sheet, the humidity in the lens barrel can be kept moderate, and water can be prevented from entering the lens barrel.

[First Embodiment]
As shown in FIG. 1, the camera system 2 includes a camera body 3 and a lens barrel 4. A lens barrel 4 is detachably attached to the camera body 3, and the camera body 3 and the lens barrel 4 are electrically connected when attached.

  A bayonet claw 6 is formed on the lens side mount portion 5 provided on the rear surface of the lens barrel 4. A connection terminal 15 is provided on the bayonet claw 6. A bayonet groove 8 is formed in the body-side mount portion 7 provided on the front surface of the camera body 3. When the lens barrel 4 is attached to the camera body 3, the bayonet claw 6 is pushed in a state of being aligned with the bayonet groove 8 and then rotated. When the lock pin 9 of the main body side mount portion 7 is engaged with a pin hole (not shown) of the lens side mount portion 5, the lens barrel 4 is positioned. Further, as the lens barrel 4 is positioned, the connection terminal 15 of the lens side mount unit 5 is connected to the connection terminal 16 (see FIG. 5) of the main body side mount unit 7. The main body side mount portion 7 is provided with a mount lid 11 that is spring-biased in the forward direction. The mount lid 11 is pressed by the lens side mount portion 5 when the lens barrel is mounted, and moves backward. To do. The mount lid 11 plays a role of preventing dust from entering the camera body 3 when the lens barrel is not attached.

  The main body side mount portion 7 is provided with a lock release button 10 that interlocks with the lock pin 9. The lock release button 10 is operated when the lens barrel 4 is removed, and can be released by moving the lock pin 9 backward by pressing.

  On the upper surface of the camera body 3, there are provided a release button 12 that is pressed during shooting, and a mode switching unit 13 that is operated when switching between shooting and playback modes. The release button 12 has a two-stage push structure. When the release button 12 is lightly pressed (half pressed), a shooting preparation operation such as focusing is performed. When further pressed (fully pressed) in this state, a photographing operation is performed.

  On the rear surface of the camera body 3, an LCD 81 for displaying a photographed image and various setting conditions and a power switch 87 are provided (see FIG. 5).

  As shown in FIG. 2, the lens barrel body 20 of the lens barrel 4 includes an inner cylinder 21 and an outer cylinder 22 that is in close contact with the outer peripheral surface of the inner cylinder 21. A metal is used for the material of the lens barrel body 20, and for example, aluminum is used. The lens barrel body 20 incorporates lens groups 23 and 24, a CCD 25, a mounting substrate 26, and the like. A rear wall portion 22a is formed in the outer cylinder 22, and a rear end is closed by the rear wall portion 22a. The lens side mount portion 5 described above is formed on the rear surface of the rear wall portion 22a.

  A fixed lens group 23 including a lens 23a and a lens 23b is disposed inside the front portion of the inner cylinder 21 (left portion in the figure). The outer diameter of the fixed lens group 23 is substantially the same as the inner diameter of the inner cylinder 21, and the fixed lens group 23 is fixed in a state where the inner peripheral surface of the inner cylinder 21 is airtightly closed.

  A focus lens unit 28 is disposed behind the fixed lens group 23. The focus lens unit 28 includes a focus lens group 24 and a lens frame 30 that holds the focus lens group 24 so as to cover the outer periphery of the focus lens group 24. The focus lens group 24 includes a focus lens 24a and a focus lens 24b. The lens frame 30 is formed in a donut shape, and the outer diameter of the lens frame 30 is approximately the same size as the inner diameter of the inner cylinder 21.

  A guide hole 30a is formed in the lower portion of the lens frame 30, and the guide hole 30a is fitted to a guide bar 31 disposed in parallel to the optical axis. A ball nut 32 is embedded and fixed in the upper part of the lens frame 30, and the ball nut 32 is screwed into a ball screw 33. A gear 34 is fixed to the front portion of the ball screw 33, and the gear 34 meshes with a gear 35. The gear 35 is fixed to a shaft 36 a of a focus motor 36 fixed to the lens barrel body 20. When the focus motor 36 is driven and the shaft 36a rotates, the ball screw 33 rotates, and the lens frame 30 holding the focus lens group 24, that is, the focus lens unit 28 moves in the optical axis direction.

  A CCD 25 is disposed behind the focus lens unit 28. The CCD 25 is held by the partition plate 40 so as to cover the side, and the rear surface of the CCD 25 is exposed. The partition plate 40 is formed in a disc shape, and an opening 40a through which subject light to the CCD 25 passes is formed at the center. The partition plate 40 is made of a material with high heat dissipation. A shutter mechanism and a diaphragm mechanism (not shown) are disposed in front of the CCD 25. Note that a structure may be adopted in which the CCD is held by fixing the rear surface of the CCD to a holding plate having high heat dissipation and fixing a part of the holding plate to the partition plate.

  The lens barrel 4 includes a first space 43 formed between the focus lens unit 28 and the partition plate 40, a second space 44 formed between the partition plate 40 and the rear wall portion 22a, and a fixed lens group. And a third space 45 formed between the focus lens unit 28 and the focus lens unit 28.

  A mounting board 26 on which various circuits are mounted is disposed behind the CCD 25, and the mounting board 26 is parallel to the CCD 25. The mounting substrate 26 has a mounting surface directed forward and a back surface fixed to a disc-shaped holding plate 41. The mounting substrate 26 and the holding plate 41 are made of a material with high heat dissipation.

  On the mounting board 26, an analog signal processing circuit 74 (see FIG. 5), details of which will be described later, an A / D conversion circuit 75, a data communication circuit 76, a CCD drive circuit 73, a lens barrel CPU 71, and a focus motor drive circuit 72 are provided. Etc. are implemented. Note that some of the circuits described above may be provided on the camera body 3 side. In the present embodiment, a circuit provided on the camera body 3 side may be additionally mounted on the mounting substrate 26 on the lens barrel 4 side. For example, a digital signal processing circuit 79 (see FIG. 5) may be added to the mounting board 26 and mounted.

  Radiating fins 42 are provided between the CCD 25 and the mounting substrate 26. The radiating fins 42 are composed of a plurality of metal plates arranged in parallel, and these metal plates are in parallel with a line connecting a vent 46b and a vent 47b described later. The radiation fins 42 are in contact with the rear surface of the CCD 25 and the mounting surface (front surface) of the mounting substrate 26. FIG. 3 is a perspective view of the partition plate 40, the CCD 25, and the heat radiation fin 42 taken out and viewed from the rear side.

  As shown in FIG. 2, a first passage 46 and a second passage 47 are formed between the inner cylinder 21 and the outer cylinder 22. As shown in FIG. 4, each of the passages 46 and 47 is a groove formed on the outer peripheral surface of the inner cylinder 21 so as to extend in the axial direction, and is formed into a tubular shape with the inner cylinder 21 fitted into the outer cylinder 22. Is. The end of the groove penetrates in the radial direction of the inner cylinder 21, and the openings of the through holes serve as the vent holes 46 a and 46 b of the first passage 46 and the vent holes 47 a and 47 b of the second passage 47.

  As shown in FIG. 2, the front vent 46 a of the first passage 46 is disposed between the focus lens unit 28 and the partition plate 40, and the rear vent 46 b of the first passage 46 is located behind the partition plate 40. Be placed. Accordingly, the first space 43 and the second space 44 communicate with each other through the first passage 46.

  The vent 47a in front of the second passage 47 is disposed between the fixed lens group 23 and the focus lens unit 28, and the vent 47b in the rear of the second passage 47 is disposed behind the partition plate 40. Accordingly, the second space 44 and the third space 45 communicate with each other through the second passage 47. The vent 46 b of the first passage 46 and the vent 47 b of the second passage 47 are arranged to face each other via the heat radiating fins 42. As a result, when an air flow occurs in the second space 44, the air flow passes in the vicinity of the radiation fins 42.

  As shown in the block diagram of FIG. 5, the focus motor 36 is connected to the focus motor drive circuit 72, and the drive is controlled by the lens barrel CPU 71 via the focus motor drive circuit 72. The lens barrel CPU calculates the amount of movement of the focus motor 36 by evaluating the contrast of the image based on the imaging signal output from the CCD 25.

  The CCD 25 is connected to a CCD drive circuit 73, and the drive is controlled by the lens barrel CPU 71 via the CCD drive circuit 73. The CCD 25 converts an optical subject image into an electrical imaging signal and outputs it. The imaging signal output from the CCD 25 is input to the analog signal processing circuit 74. The analog signal processing circuit 74 has a function of removing noise from the signal by performing correlated double sampling and a function of amplifying the signal, and outputs the image signal after performing these processes.

  The imaging signal amplified to an appropriate level is digitally converted by the A / D conversion circuit 75 into image data. This image data is transmitted to the camera body 3 side via the data communication circuit 76. The lens barrel CPU 71 controls photographing processing, image processing, and the like on the lens barrel 4 side while communicating with the camera body CPU 85.

  Image data from the lens barrel 4 is written into the memory 78 via the data communication circuit 77. The digital signal processing circuit 79 reads image data from the memory 78 and performs processing such as gradation conversion, white balance correction, and γ correction. The image data that has undergone various processes is input to the LCD drive circuit 80 and displayed on the LCD 81 as a through image.

  When the release button 12 is fully pressed, the image data subjected to various processes is recorded on the recording medium 83 under the control of the media controller 82. When the release button 12 is fully pressed, the strobe 14 is driven according to the amount of light from the shooting environment. The camera main body CPU 85 controls photographing processing, image display processing, recording processing, and the like on the camera main body 4 side while communicating with the lens barrel CPU 71. A release button 12, a mode switching unit 13, and a power switch 87 are connected to the camera body CPU 85.

  A battery 86 is disposed in the camera body 3 and supplies power to each part of the camera body 3. The battery 86 is connected to the lens barrel 4 via the connection terminals 15 and 16, and supplies power to each part of the lens barrel 4.

  Hereinafter, the operation of the above configuration will be described. When the lens barrel 4 is attached to the camera body 3, the lens barrel 4 and the camera body 3 are electrically connected.

  When the power switch 87 of the camera body 3 is turned on and the mode switching unit 13 is operated to set the shooting mode, the camera is ready for shooting. A through image is displayed on the LCD 81. When the release button 12 is pressed halfway, focusing is performed, and when the release button 12 is fully pressed, shooting is performed, and image data obtained at that time is recorded on the recording medium 83.

  With the above photographing operation, the CCD 25 and the mounting substrate 26 in the lens barrel 4 generate heat. The heat of the CCD 25 is transferred to the air in the second space 44 through the heat radiation fins 42 or directly from the rear surface of the CCD 25. Further, the heat of the mounting substrate 26 is transmitted to the air in the second space 44 through the heat radiation fins 42 or directly from the mounting surface. Thereby, the air in the vicinity of the radiation fins 42 in the second space 44 is heated.

  When focusing is performed, as shown in FIG. 6, the focus lens unit 28 is in the rear direction (left direction in the figure) or the front direction (right direction in the figure) while being in contact with the inner peripheral surface of the inner cylinder 21. Moving. As shown in FIG. 6A, when the focus lens unit 28 moves backward, the air in the first space 43 is compressed and the atmospheric pressure increases, and the atmospheric pressure in the third space 45 decreases. As a result, air flows into the second space 44 through the first passage 46, and air flows out of the second space 44 through the second passage 47. An air flow is generated in the second space 44, and a part of the heated air in the vicinity of the radiating fins 42 moves to the second passage 47 and the third space 45, and the heated air is dispersed. Thereby, the CCD 25 and the mounting substrate 26 are efficiently cooled.

  On the other hand, as shown in FIG. 6B, when the focus lens unit 28 moves in the forward direction, the atmospheric pressure in the third space 45 increases and the atmospheric pressure in the first space 43 decreases. As a result, air flows into the second space 44 through the second passage 47 and flows out of the second space 44 through the first passage 46. An air flow is generated in the second space 44, and a part of the heated air in the vicinity of the radiating fins 42 moves to the first passage 46 and the first space 43, and the heated air is dispersed. Thereby, the CCD 25 and the mounting substrate 26 are efficiently cooled.

  Thus, since the CCD 25 and the mounting substrate 26 are efficiently cooled, the CCD 25 and the mounting substrate 26 do not rise to a high temperature, and their performance does not deteriorate.

[Second Embodiment]
A lens barrel having a configuration different from that of the lens barrel 4 described in the first embodiment is shown in the second embodiment. In the description of the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 7, in the lens barrel 100 of the second embodiment, a barrel body 101 is used instead of the barrel body 20 of the first embodiment. Further, a ventilation hole 40b is formed instead of the first passage 46 of the first embodiment, and the heat radiating tube 102 is used instead of the second passage 47 of the first embodiment.

  The lens barrel body 101 is formed in a cylindrical shape, and a focus lens unit 28, a fixed lens group 23, and the like are disposed on the inner side. A rear wall 101a is formed in the lens barrel main body 101, and the rear end is closed by the rear wall 101a. The heat radiating tube 102 is spirally wound around the outer peripheral surface of the barrel main body 101. A front end 102 a of the heat radiating tube 102 is inserted into a through hole 103 formed in the lens barrel body 101 and is positioned between the fixed lens group 23 and the focus lens unit 28. The rear end 102 b of the heat radiating tube 102 is inserted into the through hole 104 formed in the lens barrel body 101 and is positioned behind the partition plate 40. The second space 44 and the third space 45 communicate with each other through the heat radiating tube 102. The vent hole 40b is formed through the partition plate 40. The first space 43 and the second space 44 communicate with each other through the vent hole 40b.

  The vent hole 40 b and the end portion 102 b of the heat radiating tube 102 are disposed on the opposite sides via the heat radiating fins 42. Thereby, when an air flow is generated in the second space 44, the air flow passes in the vicinity of the radiation fins 42.

  When the focus lens unit 28 moves rearward, air flows into the second space 44 through the vent hole 40b, and air flows out of the second space 44 through the heat radiating tube 102. An air flow is generated in the second space 44, and the heated air near the radiating fins 42 moves to the radiating pipe 102. The heat of the air that has moved to the heat radiating tube 102 is radiated from the outer surface of the heat radiating tube 102 to the external air. Thereby, the CCD 25 and the mounting substrate 26 are efficiently cooled.

  On the other hand, when the focus lens unit 28 moves in the forward direction, air flows into the second space 44 through the heat radiating tube 102 and air flows out of the second space 44 through the vent hole 40b. An air flow is generated in the second space 44, the heated air in the vicinity of the radiation fins 42 moves to the first space 43, and the heated air is dispersed. Thereby, the CCD 25 and the mounting substrate 26 are efficiently cooled.

  In the second embodiment, since the heat radiating tube 102 is used, the cooling efficiency is high, which is effective when designing with an emphasis on heat dissipation.

[Third Embodiment]
A lens barrel having a configuration different from the lens barrel 4 described in the first and second embodiments is shown in the third embodiment. In the description of the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 8, in the lens barrel 200 of the third embodiment, a barrel body 201 is used instead of the barrel body 20 of the first embodiment. Vent holes 202 and 203 are formed in the lens barrel main body 201, and a vent hole 40 b is formed in the partition portion 40.

  The lens barrel main body 201 is formed in a cylindrical shape, and a focus lens unit 28, a fixed lens group 23, and the like are disposed on the inner side. A rear wall 201a is formed in the lens barrel body 201, and the rear end is closed by the rear wall 201a. The air hole 202 is formed between the fixed lens group 23 and the focus lens unit 28. The vent hole 203 is formed behind the partition plate 40. Thereby, the 2nd space 44 and the 3rd space 45 communicate with external air, respectively. The vent hole 40b is formed through the partition plate 40. The first space 43 and the second space 44 communicate with each other through the vent hole 40b.

  The ventilation hole 40b and the ventilation hole 203 are disposed on the opposite sides with respect to the radiation fin 42 as a center. Thereby, when an air flow is generated in the second space 44, the air flow passes in the vicinity of the radiation fins 42. Note that moisture-permeable and waterproof sheets 204 and 205 are attached to the inner peripheral surface of the barrel main body 201 so as to cover the ventilation holes 202 and 203 from the inside, respectively. As a result, water can be prevented from entering the lens barrel 4 and the humidity in the lens barrel 4 can be kept moderate.

  When the focus lens unit 28 moves in the rearward direction, air flows into the second space 44 through the vent hole 40b, and air flows out of the second space 44 through the vent hole 203. An air flow is generated in the second space 44, and the heated air in the vicinity of the radiation fins 42 is discharged to the outside. Thereby, the CCD 25 and the mounting substrate 26 are efficiently cooled. External air flows into the third space 45 through the vent hole 202.

  On the other hand, when the focus lens unit 28 moves in the forward direction, air flows out from the second space 44 through the vent hole 40 b and air flows into the second space 44 through the vent hole 203. An air flow is generated in the second space 44, and a part of the heated air in the vicinity of the radiating fins 42 moves to the first space 43, and the heated air is dispersed. Thereby, the CCD 25 and the mounting substrate 26 are efficiently cooled.

  In 3rd Embodiment, since the heated air can be discharge | released directly outside, cooling efficiency becomes high.

  In the above embodiment (first to third embodiments), the focus lens unit is moved only at the time of shooting preparation. However, the focus lens unit may be moved at the time of playback mode other than the time of shooting preparation.

  In the above embodiment, the focus lens unit is used as the moving lens unit, but another lens unit such as a zoom lens unit may be used.

  In the above embodiment, the moving lens unit is closely attached to the inner peripheral surface of the lens barrel body, but a slight gap may be provided as long as an air flow can be generated in the second chamber.

  In the above embodiment, the moving lens unit is automatically moved, but may be moved manually.

  In the above embodiment, description has been made using a lens interchangeable digital camera with a detachable lens barrel. However, the present invention is also applied to a digital camera in which the lens barrel and the camera body are integrated. Can do.

It is an external appearance perspective view of a camera system. It is sectional drawing when a lens-barrel is cut | disconnected in an axial direction. It is an external appearance perspective view of a partition plate, CCD, and a radiation fin. It is an external appearance perspective view of an inner cylinder. It is a block diagram which shows the electric constitution of a camera system. It is explanatory drawing which shows the flow of the air in 3rd space. FIG. 6 is a cross-sectional view of the second embodiment when the lens barrel is cut in the axial direction. FIG. 6 is a cross-sectional view of the third embodiment when the lens barrel is cut in the axial direction.

Explanation of symbols

2 Camera system 3 Camera body 4, 100, 200 Lens barrel 20, 101, 201 Lens barrel body 21 Inner tube 22 Outer tube 22a, 101a, 201a Rear wall portion 23 Fixed lens group 24 Focus lens group 25 CCD
26 mounting substrate 28 focus lens unit 30 lens frame 40 partition plate 40b vent hole 43 first space 44 second space 45 third space 46 first vent portion 47 second vent portion 102 heat radiating pipe 202 vent hole 203 vent hole

Claims (7)

In a lens barrel that has an image sensor and is detachable from the camera body,
A movable lens unit movable in the optical axis direction;
A partition plate that holds the imaging device behind the moving lens unit and partitions the space between the moving lens unit and the barrel main body rear wall substantially perpendicular to the optical axis;
A first passage that communicates a first space between the movable lens unit and the partition plate and a second space between the partition plate and the rear wall,
A lens barrel, wherein an air flow is generated in the second space through the first passage as the movable lens unit moves. A fixed lens disposed in front of the moving lens unit;
2. The lens barrel according to claim 1, further comprising a third space between the fixed lens and the movable lens unit and a second passage communicating the second space.   The lens barrel according to claim 2, wherein the first and second passages are formed inside a barrel main body.   The first passage is a vent hole formed in the partition plate, and the second passage is a heat radiating tube spirally wound around the outer peripheral surface of the lens barrel body and having an end connected to each space. The lens barrel according to claim 2.   The lens barrel according to claim 1, further comprising a second passage communicating the space outside the lens barrel and the second space.   6. The lens barrel according to claim 5, wherein the first passage is a vent hole formed in the partition plate, and the second passage is a vent hole formed in the barrel main body. In the second space, a mounting board on which a circuit for processing an output signal from the imaging element is mounted is provided so as to be located behind the imaging element, and the rear surface of the imaging element and the mounting board The lens barrel according to any one of claims 1 to 6, further comprising a heat dissipating fin in contact with the front surface.

Images