JP2006267694A - Lens barrel and lens unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact lens barrel equipped with a ranging sensor and to provided a lens unit. <P>SOLUTION: An objective lens 20 and an AF sensor 21 which detects a subject distance are exposed from the front face of a lens unit 10. The AF sensor 21 is installed in a position where photographic light flux is not interrupted in the neighborhood of the objective lens 20. Also, a portion of the AF sensor 21 is arranged inside an outer shape 21a of the object lens 20. Thus, it is not necessary to increase the outer diameter of the lens unit 10 so as to secure a space in which the AF sensor 21 is arranged, and the lens unit 10 is downsized accordingly. Since a parallax between the AF sensor 21 and a photographic lens is reduced, a subject distance is accurately detected. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lens barrel and a lens unit that include a distance measuring sensor that detects a subject distance.

In a camera including a lens barrel that holds a photographing lens, a distance measuring sensor that detects a subject distance is provided in the camera body. For this reason, the distance measuring sensor and the photographing lens are separated from each other, and parallax occurs. In addition, there is known a camera in which a distance measuring sensor for detecting a subject distance is arranged in the vicinity of an objective lens arranged closest to the object among photographing lenses (see, for example, Patent Document 1). In this camera, since the distance measuring sensor is disposed in the vicinity of the objective lens, the parallax between the distance measuring sensor and the photographing lens can be reduced.
Japanese Patent Publication No. 56-54609

  However, in the camera described in Patent Document 1, the distance measuring sensor is disposed in the vicinity of both ends in the radial direction of the objective lens. For this reason, there has been a problem that the outer diameter of the lens barrel is increased and it is difficult to reduce the size of the lens barrel.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a small lens barrel and a lens unit including a distance measuring sensor.

  In order to solve the above-described problems, the lens barrel of the present invention is a lens barrel that holds a photographing lens and includes a distance measuring sensor that detects a subject distance. Of these, the distance sensor is provided in the vicinity of the objective lens arranged closest to the object side and at a position that does not block the photographing light beam, and at least a part of the distance measuring sensor is disposed inside the outer shape of the objective lens. It is what.

  The distance measuring sensor may be disposed in front of the objective lens, or may be disposed behind the objective lens to detect the subject distance through the objective lens.

  Furthermore, the lens barrel of the present invention is a lens barrel that holds a photographic lens and includes a distance measuring sensor that detects a subject distance, and among the photographic lenses, the objective lens arranged closest to the object side is: The end portion outside the region where the photographing light beam enters is cut, and the distance measuring sensor is arranged so as to be close to the cut surface.

  The distance measuring sensor preferably detects the presence or absence of a lens cap that is detachably attached to the front surface of the objective lens. Furthermore, it is preferable that a lens barrier that can be opened and closed between a shielding position that covers the objective lens and a retracted position that is retracted from the objective lens is provided, and the distance measuring sensor detects opening and closing of the lens barrier.

  Furthermore, the lens unit of the present invention includes the lens barrel and an image sensor that is disposed in the lens barrel and picks up a subject image formed by the photographing lens, and is detachably attached to the camera body. It is characterized by that.

  According to the lens barrel of the present invention, the distance measuring sensor is provided at a position that does not block the photographing light flux in the vicinity of the objective lens, and at least a part of the distance measuring sensor is disposed inside the outer shape of the objective lens. Yes. For this reason, it is not necessary to increase the outer diameter of the lens barrel in order to secure an arrangement space for the distance measuring sensor. For this reason, the lens barrel provided with the distance measuring sensor can be miniaturized. Further, the parallax between the distance measuring sensor and the photographic lens is reduced, and the subject distance can be accurately detected.

  A distance measuring sensor is provided behind the objective lens, and the distance measuring sensor detects a subject distance through the objective lens. For this reason, it is possible to further reduce the size of the lens barrel by disposing the distance measuring sensor further inside, and to further reduce the parallax between the distance measuring sensor and the photographing lens.

  Furthermore, according to the lens barrel of the present invention, the objective lens is provided with a distance measuring sensor so that the outer end of the objective lens is cut off from the region where the photographic light beam is incident and is close to the cut surface. For this reason, it is not necessary to increase the outer diameter of the lens barrel in order to secure an arrangement space for the distance measuring sensor. For this reason, the lens barrel provided with the distance measuring sensor can be miniaturized. Further, the parallax between the distance measuring sensor and the photographic lens is reduced, and the subject distance can be accurately detected.

  In addition, since the distance measuring sensor detects the presence or absence of the lens cap or the opening / closing of the lens barrier, when the objective lens is shielded by the lens cap or the lens barrier, it is not necessary to drive the components in the lens barrel. Wasteful power consumption can be reduced.

  First, the lens unit 10 according to the first embodiment will be described. A lens unit 10 shown in FIG. 1 is an interchangeable lens barrel that is detachably attached to a camera body 11, and stores a CCD that is an image sensor as will be described later.

  An objective lens 20 and an autofocus sensor (hereinafter referred to as AF sensor) 21 that is a distance measuring sensor are exposed on the front surface of the lens unit 10, and a mount portion 22 is provided on the rear surface. . The lens unit 10 includes a focus ring 23, a zoom ring 24, and an aperture ring 25. Moreover, the lock release button 26 is provided in the outer peripheral surface of these rings 23-25, respectively, When these lock release buttons 26 are pressed, these can be rotated.

  A front surface of the camera body 11 is provided with a mount unit 30, a release button 31, and a strobe light emitting unit 32 that irradiates strobe light toward a subject. An operation unit 36 including a power button 33, a shutter button 34, and an operation dial 35 is provided on the upper surface. The power button 33 is pressed when the camera body 11 is turned on or off. The shutter button 34 is pressed when shooting. The operation dial 35 is operated when switching between the shooting mode and the reproduction mode. An LCD (not shown) is provided with an LCD for displaying images, setting screens, and the like.

  When the lens unit 10 is attached to the camera body 11, the lens unit 10 is attached to the camera body 11 by inserting the mount portion 22 into the recess 30 a formed in the mount portion 30. Thus, when the lens unit 10 is attached to the camera body 11, the lens unit 10 and the camera body 11 are electrically connected. The release button 31 is pressed when the lens unit 10 is removed from the camera body 11.

  The lens unit 10 includes a zoom ring 24 adjacent to the aperture ring 25, and a unit between a shortened position where the entire length of the unit is shortened and an extended position where the zoom ring 24 is moved forward to extend the entire length of the unit. The total length is made extendable. When the lens unit 10 is not used, the zoom ring 24 is moved to the shortened position, and when the lens unit 10 is used, the zoom ring 24 is moved to the extended position. The zoom ring 24 can be rotated when moved to the extended position.

  Below, the structure of the lens unit 10 is demonstrated using FIG.2 and FIG.3. The lens unit 10 includes a fixed cylinder 40, a moving cylinder 41, a cam cylinder 42, and a cover cylinder 43. The above-described mount portion 22 is provided on the back surface of the fixed cylinder 40 and is fixed to the camera body 11. Three guide shafts 40 a are provided on the front end side of the fixed cylinder 40. The guide shaft 40a has a distal end protruding from the outer peripheral surface and the inner peripheral surface, and the three guide shafts 40a are arranged at three circumferential positions around the optical axis L. A diaphragm ring 25 is rotatably provided on the outer peripheral surface on the rear end side.

  The moving cylinder 41 is disposed inside the fixed cylinder 40. The movable cylinder 41 is provided with three guide grooves 41a that are formed in parallel with the optical axis L1 and engage with the above-described guide shaft 40a. For this reason, the movable cylinder 41 moves straight (between the position stored in the fixed cylinder 40 (position shown in FIG. 2) and the position pulled forward from the fixed cylinder 40 (position shown in FIG. 3) ( It is movable in the direction of the optical axis L) and its rotation is restricted.

  The cam cylinder 42 is disposed outside the fixed cylinder 40 and is rotatably held by the moving cylinder 41. Further, the cover cylinder 43 is disposed outside the cam cylinder 42 and is provided so as to cover the cam cylinder 42. The cover cylinder 43 is fixed to the movable cylinder 41, and the front end of the cover cylinder 43 projects forward from the front end of the movable cylinder 41. A focus ring 23 and a zoom ring 24 are disposed outside the governor tube 43, and these rings 23 and 24 are rotatably held by the cover tube 43.

  As described above, the cam cylinder 42 and the cover cylinder 43 are held by the moving cylinder 41, and the focus ring 23 and the zoom ring 24 are held by the cover cylinder 43. For this reason, when the zoom ring 24 is moved between the shortened position (position shown in FIG. 2) and the extended position (position shown in FIG. 3), these move together with the fixed cylinder 40. .

  In the lens unit 10, a photographing lens 50 and a CCD 51, which is an image pickup device for picking up a subject image formed by the photographing lens 50, are provided. The taking lens 50 includes an objective lens 20 that is a first group lens, a second group lens 52, a third group lens 53, and a fourth group lens 54.

  The moving cylinder 41 holds the objective lens 20 and the second group lens 52. The fixed tube 40 holds a shutter unit 55 having a diaphragm function, a third group lens 53, a filter unit 56, a fourth group lens 54, and a CCD 51.

  The objective lens 20 is fixed to the front surface of the moving cylinder 41. The second lens group 52 is a zoom lens, is disposed in the movable cylinder 41, and is held so as to advance and retract along the optical axis L1. The shutter unit 55 is fixed to the front end portion in the fixed cylinder 40, and the third group lens 53 and the filter unit 56 are sequentially arranged behind the shutter unit 55 and fixed in the fixed cylinder 40. The third group lens 53 is held by a lens holding frame 69, and the lens holding frame 69 is fixed to the fixed cylinder 40. The shutter unit 55 and the filter unit 56 are held by the lens holding frame 69. Further, the filter unit 56 reduces the photographing light by inserting the ND filter in the optical path of the photographing light so as to be freely inserted and removed.

  The fourth group lens 54 is disposed behind the filter unit 56. The fourth group lens 54 is a focus lens, is held by a lens holding frame 60, and is held movably along the optical axis L1 in the fixed cylinder 40. The lens holding frame 60 is screwed with the drive shaft 61 a of the focus motor 61 and is further prevented from rotating by the guide shaft 62. For this reason, when the focus motor 61 is rotationally driven, the fourth lens group 54 moves forward and backward along the optical axis L1. In addition, a CCD 51 is disposed behind the fourth lens group 54 and images a subject image formed by the photographing lens 50.

  The objective lens 20 described above is held by a lens holding frame 65, and this lens frame 65 is attached to the front side of the movable cylinder 41. The AF sensor 21 is provided in front of the objective lens 20 at a position that does not block the photographing light flux. The photographing light flux is a light flux incident on the imaging surface of the CCD 51 among the subject light flux incident on the photographing lens 50, and is a light flux within a range surrounded by two-dot chain lines LA and LB.

  The AF sensor 21 is an active AF sensor, and includes a light projecting unit 21a that irradiates infrared rays toward a subject and a light receiving unit 21b that receives reflected light, as shown in FIG. The AF sensor 21 detects the subject distance based on the time until the irradiated infrared reflected light is received. The AF sensor 21 is not limited to the one using infrared rays, but may be one that detects the subject distance based on the time until the reflected wave returns by irradiating an ultrasonic wave.

  A part of the AF sensor 21 is disposed on the inner side (optical axis L1 side) than the outer shape 20a of the objective lens 20. The AF sensor 21 is provided on the front surface of the movable cylinder 41 in a state where the AF sensor 21 is mounted on an FPC (Flexible Printed Circuit) FPC 66 that is a flexible circuit board. The FPC 66 is disposed along the outer periphery of the objective lens 20.

  A decorative plate 67 is provided on the front surface of the cover cylinder 43. An opening 67a for exposing the objective lens 20 and an opening 67b for exposing the AF sensor 21 are formed in the decorative plate 67, and the objective lens 20 and the AF sensor 21 are exposed to the outside.

  The second group lens 52 is held by a lens holding frame 68. The lens holding frame 68 is provided with three cam followers 68a. The moving cylinder 41 is formed with three rectilinear guide grooves 41b substantially parallel to the optical axis L1. These straight guide grooves 41b are inserted through the cam followers 68a so that the tips of the cam followers 68a protrude. The lens holding frame 68 is prevented from rotating by these linear guide grooves 41b. The cam cylinder 42 is provided with a cam opening 42a that engages with the cam follower 68a, a connecting pin 42b, and an engagement groove 42c that engages with the guide shaft 40a.

  The cam opening 42a engages with a tip portion of a cam follower 68a that protrudes from the rectilinear guide groove 41b. Therefore, when the cam cylinder 41 is rotated, the second group lens 52 moves along the optical axis L in accordance with the displacement of the cam opening 42a in the optical axis direction.

  The connection pin 42 b is inserted through an opening 43 a formed in the cover cylinder 43, and the tip end portion of the connection pin 42 b is engaged with an engagement hole 24 a formed on the inner peripheral surface of the zoom ring 24. The opening 43 a is formed along the circumferential direction, and the cam cylinder 42 rotates together with the zoom ring 42 when the zoom ring 24 is rotated.

  The engaging groove 42c guides the straight movement of the cam cylinder 42 from the shortened position to the extended position, and guides the rotation of the cam cylinder 42 at the extended position.

  The focus ring 23 and the aperture ring 25 described above are rotated by the photographer when the focus adjustment and the aperture diameter of the aperture are manually adjusted. These rotational positions are detected by a position sensor (not shown), and the position of the fourth group lens 54 and the aperture diameter of the aperture of the shutter unit 55 are changed based on the rotational positions detected by these position sensors. Is done.

  As described above, the AF sensor 21 is provided in front of the objective lens 20, and a part of the AF sensor 21 is arranged inside the outer shape 20 a of the objective lens 20. In order to ensure, there is no need to increase the outer diameter of the lens unit. For this reason, the lens unit provided with the AF sensor 21 can be reduced in size.

  In addition, the parallax between the AF sensor 21 and the photographic lens 50 is smaller than when the AF sensor 21 is arranged outside the objective lens 20, and the subject distance can be accurately detected.

  Next, the electrical configuration of the lens unit 10 will be described. As shown in FIG. 5, the lens unit 10 is provided with a unit controller 70 that controls each part in the unit. The unit control unit 70 includes a ROM that stores a control program for controlling each unit and a RAM that temporarily stores work data. The unit control unit 70 controls each unit based on this control program.

  An AF sensor 21, a motor driver 71, and position sensors 72 and 73 are connected to the unit controller 70. The AF sensor 21 detects the subject distance and outputs it to the unit controller 70. The motor driver 71 is connected to the motor 61, and the unit controller 70 drives the motor 61 by controlling the motor driver 71 based on the subject distance detected by the AF sensor 21. The motor 61 moves the fourth lens group 54 back and forth along the optical axis L1 to perform focus adjustment.

  The position sensor 72 detects the rotational position of the focus ring 23, and the position sensor 73 detects the rotational position of the aperture ring 25. When the focus ring 23 is rotated, the unit controller 70 adjusts the focus by moving the fourth group lens 54 based on this rotational position. Further, when the aperture ring 25 is rotated, the unit controller 70 controls the shutter unit 55 and the filter unit 56 based on this rotational position, and adjusts the amount of light incident on the CCD 51.

  In addition, a CCD 51 is connected to the unit controller 70 via a CCD driver 75. The unit controller 70 controls the CCD driver 75 to drive the CCD 51. The CCD 51 converts the subject image into an electrical signal by photoelectric conversion, and acquires image data that is an analog signal.

  Further, the CCD 51 is connected to an analog signal processing unit 76 and outputs image data to the analog signal processing unit 76. The analog signal processing unit 76 is connected to the unit control unit 70 via the data bus 77 and is controlled by the unit control unit 70. The analog signal processing unit 76 performs noise removal and amplification processing on the image data and outputs the processed image data to the A / D converter 78. The A / D converter 78 converts the image data from an analog signal to a digital signal.

  An AE / AF detector 79 is connected to the A / D converter 78 and outputs image data converted into a digital signal. The AE / AF detection unit 79 is controlled by the unit control unit 70, detects the in-focus position where the amplitude value of the high frequency component of the image data is maximum, and outputs the AF detection value. Further, the AE / AF detection unit 79 detects an AE detection value at which the exposure is optimal, and outputs the AE detection value.

  The unit control unit 70 adjusts the position of the fourth group lens 54 based on the subject distance detected by the AF sensor 21, and then, based on the AF detection value acquired from the AE / AF detection unit 79, the fourth group The position of the lens 54 is finely adjusted. Further, the unit controller 70 controls the shutter unit 55 and the filter unit 56 based on the AE detection value, and adjusts the amount of light incident on the CCD 51.

  In addition, a serial driver 80 and a power supply control unit 81 are connected to the unit control unit 70 via a data bus 77. The unit controller 70 controls the serial driver 80, and is connected to the camera body 11 via a mount contact 82 provided on the back surface of the mount 22 and a mount contact 83 provided on the mount 30 of the camera body 11. Various operation signals and image data are transmitted and received between them.

  That is, the unit controller 70 controls the serial driver 80 to convert the image data converted into a digital signal by the A / D converter 78 into a serial signal, and outputs the serial signal to the digital camera 10.

  The power control unit 81 is connected to the mount contact 82. The power control unit 81 is supplied with power from the camera body 11 via the mount contacts 82 and 83. The unit control unit 70 controls the power supply control unit 81 to supply power to each unit in the lens unit 10. In addition, the unit control unit 70 acquires a control signal from the control unit 90 in the camera body 11 via the mount contacts 82 and 83, and controls each unit in the unit based on the control signal.

  Next, the electrical configuration of the camera body 11 will be described. The camera body 11 is provided with a control unit 90 that controls each part in the body. The control unit 90 includes a ROM that stores a control program for controlling each unit, and a RAM that temporarily stores work data. The control unit 90 controls each unit based on this control program.

  The digital signal processing unit 91 is connected to a memory 93 via a data bus 92. The digital signal processing unit 91 acquires image data from the lens unit 10 and stores the image data in the memory 93. When the image data is stored in the memory 93, the digital signal processing unit 91 performs various image processing such as gradation conversion, white balance correction, and γ correction, YC conversion processing, and the like on the image data.

  In the shooting mode, the digital signal processing unit 91 performs simple image processing and simple YC processing on the image data before the shooting process is executed, and outputs the image data to the LCD driver 95. The control unit 90 controls the LCD driver 95 to display the image data on the LCD 96 as a through image.

  When the photographing process is executed, the digital signal processing unit 91 performs image processing, YC conversion processing, compression processing, and the like on the image data. The control unit 90 is connected to the media controller 97 and controls the media controller 97 to record the compressed image data on the recording medium 98.

  In the playback mode, the control unit 90 controls the media controller 97 to read out image data from the recording medium 98, and after the digital signal processing unit 91 performs decompression processing, the image data is used as a playback image. It is displayed on the LCD 96.

  In addition, an operation unit 36 and a strobe control unit 99 are connected to the control unit 90. The control unit 99 acquires various operation signals from the operation unit 36 and executes processing corresponding to each operation signal. A strobe light emitting unit 32 is connected to the strobe control unit 99. The control unit 90 controls the strobe control unit 99 to cause the strobe light emitting unit 32 to emit light.

  In addition, the serial driver 100 and the power supply control unit 101 are connected to the control unit 90 via the data bus 92. The control unit 90 controls the serial driver 100 and transmits / receives various operation signals and image data to / from the lens unit 10 via the mount contacts 82 and 83.

  The power control unit 101 is connected to the battery 102. The power supply control unit 101 is controlled by the control unit 90, transforms the output voltage of the battery 102 to a predetermined voltage, and supplies power to each unit in the camera body 11. The power supply control unit 101 is connected to the mount contact 83 and supplies power to the lens unit 10 via the mount contacts 82 and 83.

  Although the lens unit 10 according to the first embodiment has been described above, the presence or absence of the lens cap 105 in which the above-described AF sensor 21 is detachably attached to the front surface of the lens unit 10 as shown in FIG. It may be detected. In this case, the unit control unit 70 determines whether or not the subject distance detected by the AF sensor 21 is less than a predetermined threshold. If the subject distance is less than the predetermined threshold, it is determined that there is a lens cap. If it is greater than or equal to the predetermined threshold, it is determined that there is no lens cap.

  In addition, as shown in FIG. 7, when a lens barrier 106 that can be opened and closed between a shielding position that covers the objective lens 20 and a position that retracts from the objective lens 20 is provided at the front end of the cover cylinder 43, AF The sensor 21 may detect the opening / closing of the lens barrier 106. In this case, as in the case of the lens cap 105, the opening / closing of the lens barrier 106 is detected based on whether the subject distance detected by the AF sensor 21 is less than a predetermined threshold.

  In this way, when the objective lens 20 is covered by the lens cap 105 or the lens barrier 106 by detecting the presence or absence of the lens cap 105 or the opening / closing of the lens barrier 106 by the AF sensor 21, the unit control unit 70 does not need to drive the CCD 51. For this reason, useless power consumption can be reduced. A warning message may be displayed on the LCD 96.

  Next, the lens unit 110 according to the second embodiment will be described. In the lens unit 10, the AF sensor 21 is disposed in front of the objective lens. However, in the lens unit 110 illustrated in FIG. 8, the AF sensor 21 is disposed behind the objective lens 20, as in the case of the lens unit 10. It is provided at a position that does not block the photographing light flux.

  Further, as shown in FIG. 9, the AF sensor 21 is arranged on the inner side (optical axis L1 side) than the outer shape 20a of the objective lens 20. Similarly to the lens unit 10, a decorative plate 111 is provided on the front surface of the cover cylinder 43. Unlike the decorative plate 67, the decorative plate 111 does not require an opening for exposing the AF sensor 21, so only the opening 111 a for exposing the objective lens 20 is formed. The AF sensor 21 performs infrared irradiation and reflected light reception through the objective lens 21.

  In this lens unit 111, since the AF sensor 21 can be arranged on the optical axis L1 side as compared with the lens unit 10, the parallax between the photographing lens and the AF sensor can be further reduced. For this reason, focus adjustment can be performed more accurately.

  Further, since the AF sensor 21 is provided behind the objective lens 20 and the AF sensor 21 is disposed on the inner side of the outer shape 20a of the objective lens 20, the outer diameter can be made smaller than that of the lens unit 10. . Further, since the AF sensor 21 is provided behind the objective lens 20, the length in the direction of the optical axis L <b> 1 can be shortened compared to the lens unit 10.

  Other configurations are the same as those of the lens unit 10, and the same reference numerals are given and detailed description thereof is omitted. Similarly to the lens unit 10, the AF sensor 21 may detect the presence / absence of the lens cap 105 and the opening / closing of the lens barrier 106.

  Next, the lens unit 120 which is 3rd Embodiment is demonstrated. The lens unit 120 shown in FIG. 10 differs from the lens units 10 and 110 in the shape of the objective lens. The objective lens 121 has a substantially D-shape as shown in FIG. 11, with the end portion outside the region (inside the two-dot chain lines LA and LB) where the photographing light beam enters. The objective lens 121 is held by a lens holding frame 122 and is fixed to the front surface of the movable cylinder 41.

  In addition, the lens holding frame 122 has a thin portion in contact with the cut surface 121a of the objective lens 121, and the AF sensor 21 is disposed so as to be close to the cut surface 121a.

  A decorative plate 123 is provided on the front surface of the movable cylinder 41. As in the case of the lens unit 10, the decorative plate 123 has an opening 123a for exposing the objective lens 121 and an opening 123b for exposing the AF sensor 21, and the objective lens 121 and the AF sensor 21 are exposed to the outside. Exposed.

  In the lens unit 120, as with the lens unit 10, the AF sensor 21 can be disposed on the optical axis L1 side, so that the parallax between the photographing lens and the AF sensor can be reduced. For this reason, focus adjustment can be performed accurately. Further, it is not necessary to increase the outer diameter in order to secure the space for arranging the AF sensor 21. For this reason, a lens unit can be reduced in size.

  Other configurations are the same as those of the lens unit 10, and the same reference numerals are given and detailed description thereof is omitted. Similarly to the lens unit 10, the AF sensor 21 may detect the presence / absence of the lens cap 105 and the opening / closing of the lens barrier 106.

  In the above embodiment, the case where an active AF sensor is used as a distance measuring sensor has been described as an example. However, a passive (for example, phase difference detection) AF sensor may be used.

  In the above-described embodiment, the case where a CCD is used as an image sensor has been described as an example. However, the present invention is not limited to this, and a CMOS image sensor may be used, for example.

  Furthermore, in the above-described embodiment, the lens unit including the image sensor in the lens barrel has been described as an example. However, the present invention can also be applied to a normal lens barrel that does not include the image sensor. Further, the present invention may be applied not to a lens barrel that is detachable from the camera body but to a lens barrel that is provided integrally with the camera body.

  Furthermore, in the above embodiment, the digital camera has been described as an example. However, the present invention is not limited to this, and the present invention may be applied to a digital video camera, a silver salt camera, or the like.

It is a perspective view which shows the structure of the lens unit which is 1st Embodiment. It is sectional drawing which shows the structure of a lens unit, and has shown the shortened state. It is sectional drawing which shows the structure of a lens unit, and has shown the expansion | extension state. It is a front view which shows the structure of a lens unit. It is a block diagram which shows the electrical structure of a lens unit and a camera main body. It is sectional drawing explaining the detection of a lens cap. It is sectional drawing explaining the detection of a lens barrier. It is sectional drawing which shows the structure of the lens unit which is 2nd Embodiment. It is a front view which shows the structure of a lens unit. It is sectional drawing which shows the structure of the lens unit which is 3rd Embodiment. It is a front view which shows the structure of a lens unit.

Explanation of symbols

10, 110, 120 Lens unit 11 Camera body 20, 121 Objective lens 21 AF sensor 50 Shooting lens 51 CCD
105 Lens cap 106 Lens barrier 121a Cut surface

Claims (7)

In a lens barrel that holds a photographic lens and includes a distance measuring sensor that detects a subject distance,
The distance measuring sensor is provided in the vicinity of the objective lens disposed closest to the object side of the photographing lens at a position that does not block the photographing light flux, and at least a part of the distance measuring sensor is formed from an outer shape of the objective lens. The lens barrel is also arranged on the inner side.   The lens barrel according to claim 1, wherein the distance measuring sensor is disposed in front of the objective lens.   The lens barrel according to claim 1, wherein the distance measuring sensor is disposed behind the objective lens and detects the subject distance through the objective lens. In a lens barrel that holds a photographic lens and includes a distance measuring sensor that detects a subject distance,
Among the photographing lenses, the objective lens arranged closest to the object side is cut at the outer end of the region where the photographing light beam is incident, and the distance measuring sensor is arranged so as to be close to the cut surface. A lens barrel characterized by that.   5. The lens barrel according to claim 1, wherein the distance measuring sensor detects the presence or absence of a lens cap that is detachably attached to the front surface of the objective lens.   2. A lens barrier that is openable and closable between a shielding position that covers the objective lens and a retracted position that is retracted from the objective lens, wherein the distance measuring sensor detects opening and closing of the lens barrier. The lens barrel according to any one of 4 to 4. A lens barrel according to any one of claims 1 to 6, and an image pickup device that is disposed in the lens barrel and picks up a subject image formed by the photographing lens, and is detachable from the camera body. A lens unit that is attached to a lens unit.

Images