JP2009092888A - Optical equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera capable of detecting opening/closing operation of a lens barrier even though a dedicated sensor for detecting the opening/closing operation of the lens barrier is not provided. <P>SOLUTION: The optical equipment is equipped with an optical system including a movable lens, a lens protection part capable of moving between a protection position where it covers the front of the optical system and a retreat position where it retreats to expose the front of the optical system, and a detection part detecting the position of the lens. The detection part detects also the position of the lens protection part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical apparatus.

The camera includes a lens barrier for protecting the photographing optical system. The lens barrier is configured to be openable and closable with respect to the photographic optical system. For example, the lens barrier opens to open the photographic optical system when the camera is turned on, and protects the photographic optical system when the camera is turned off. Close as you do. Therefore, the camera includes a sensor for detecting the opening / closing operation of the lens barrier. For example, the driving of the movable lens is controlled by the output of the sensor.
JP 2005-338231 A

  However, when a dedicated sensor for detecting the opening / closing position of the lens barrier is required, there is a problem that the number of parts of the camera increases and the cost increases.

  An object of the present invention is to provide a camera that can detect the opening / closing operation of a lens barrier without providing a dedicated sensor for detecting the opening / closing operation of the lens barrier.

  The optical apparatus according to claim 1, wherein the lens protection is movable between an optical system including a movable lens, a protection position that covers a front surface of the optical system, and a retracted position that exposes the front surface of the optical system. And a detection unit for detecting the position of the lens, wherein the detection unit also detects the position of the lens protection unit.

  The optical device according to claim 2 is the optical device according to claim 1, wherein the lens is a shake correction lens that corrects shake by moving a plane perpendicular to the optical axis of the optical system, The detection unit detects the position of the lens in a plane perpendicular to the optical axis of the optical system.

  An optical device according to a third aspect is the optical device according to the second aspect, wherein the detection unit is a magnetic sensor capable of detecting the intensity of a magnetic field in a specific direction.

  An optical device according to a fourth aspect of the present invention is the optical device according to the third aspect, wherein the lens protection unit includes a magnetization region polarized into an N pole and an S pole, and the magnetic sensor The position of the lens protection unit is detected by detecting a magnetic field in the magnetization region that changes with movement.

  The optical device according to claim 5 is the optical device according to claim 4, wherein a direction in which the magnetic sensor can detect the intensity of the magnetic field and a direction polarized to the N pole and the S pole of the magnetization region are provided. It is characterized by being parallel.

  The optical device according to claim 6 is the optical device according to claim 5, wherein the magnetized region is provided on a surface obtained by bending the lens protection portion perpendicularly to a plane constituting the lens protection portion. Features.

  The optical device according to claim 7 is the optical device according to claim 6, wherein the magnetic sensor detects a magnetic field of the magnetization region when the magnetization region is positioned so as to face the magnetic sensor. It is characterized by.

  The optical device according to claim 8 is the optical device according to any one of claims 1 to 7, further comprising a control unit that controls movement of the lens protection unit between a protection position and a retracted position. The control unit stops the movement of the lens protection unit based on the output of the detection unit.

  An optical device according to a ninth aspect is the optical device according to any one of the first to eighth aspects, wherein the optical system includes a reflecting portion that bends the optical axis of the subject light, and forms a subject image. It is characterized by being a bending optical system which images.

  An optical device according to claim 10 is the optical device according to any one of claims 1 to 9, wherein the optical device is a camera.

  According to the present invention, it is possible to detect the opening / closing operation of the lens barrier without providing a dedicated sensor for detecting the opening / closing operation of the lens barrier.

(First embodiment)
A first embodiment of the present invention will be described by taking an optical apparatus as an example, and here a digital camera as an optical apparatus.

  1 to 5 are diagrams showing the configuration and operation of the digital camera 1 in the present embodiment. FIG. 1 is a perspective view showing the appearance of the lens barrier unit 2 and the lens barrel 3 of the digital camera 1. The lens barrier unit 2 is disposed on the object side of the lens barrel 3 and includes a lens barrier 20, a pivot shaft 21, a lens barrier drive motor 22, and a lens barrier drive lever 23.

  The lens barrier 20 is a member for protecting the front surface of the first lens unit L1 of the lens barrel 3 described later. The lens barrier 20 is disposed so as to be a surface perpendicular or substantially perpendicular to the optical axis A1 of the photographing optical system, and is rotatably supported by the pivot shaft 21.

  In the vicinity of the pivot shaft 21, a lens barrier blade drive lever 23 and a gear train (not shown) are arranged to transmit the driving force of the lens barrier drive motor 22.

  The lens barrier drive motor 22 performs a predetermined operation on the digital camera 1, for example, power-on (ON) or disconnection (OFF) of the digital camera 1, or no operation on the digital camera 1 when the power of the digital camera 1 is ON And so on. The driving force of the lens barrier driving motor 22 is transmitted to the lens barrier 20 via a gear train (not shown) and the lens barrier driving lever 23. Thereby, the lens barrier 20 can be rotated about 90 degrees around the pivot shaft 21, the protection position covering the front surface of the first lens unit L 1 of the lens barrel 3, and the first lens unit L 1. Two positions can be taken: a retracted position where the front surface is opened. Details of the protection position and retraction position of the lens barrier 20 and the opening / closing operation of the lens barrier 20 will be described later. Note that the lens barrier 20 in FIG. 1 is in the closed position.

  The lens barrel 3 includes a bending type photographing optical system that bends the optical axis of light incident from a subject by 90 degrees. Details of the configuration of the lens barrel 3 will be described later.

  FIG. 2 is a cross-sectional view of the right side surface of the digital camera 1. The right side surface of the digital camera 1 is a side surface located on the right side when the digital camera 1 is viewed from the object side.

  The digital camera body 4 includes an opening 4 a on the object side of the digital camera body 4 for allowing light from the subject to enter the imaging optical system of the lens barrel 3. A lens barrier 20 is disposed between the digital camera body 4 and the photographing optical system so as to cover the opening 4a. Note that bent portions 20c and 20e of the lens barrier 20, which will be described later, are configured to pass through a space below the blur correction unit 30.

  The lens barrel 3 includes an imaging optical system in which a first lens unit L1, a prism P, a second lens unit L2, a third lens unit L3, a fourth lens unit L4, and a fifth lens unit L5 are arranged in order from the object side. , A blur correction unit 30 including a fourth lens unit L4, an image sensor 31 and a low-pass filter 32 are provided.

  The first lens unit L1 is an objective lens located closest to the object side in the photographing optical system.

  The prism P is a right-angle prism that totally reflects light from the subject emitted by the first lens unit L1 and bends its traveling direction by 90 degrees.

  Here, the optical axis on the incident side of the prism P in the photographing optical system is A1, and the optical axis on the exit side of the prism P is A2.

  The second lens group L2 is a lens group that is provided on the exit side of the prism P and whose position with respect to the prism P is fixed.

  The third lens group L3 is provided on the exit side of the second lens group L2, and is moved along the optical axis A2 by a lens driving unit such as a stepping motor (not shown) to adjust the focus on the subject. A group.

  The fourth lens group L <b> 4 is a lens group that is provided on the exit side of the third lens group L <b> 3 and constitutes a part of the blur correction unit 30. The blur correction unit 30 is caused by the movement of the digital camera by moving the position of the image formed on the image sensor 31 by displacing the fourth lens unit L4 within a plane orthogonal to the optical axis A2. This is to reduce image blur on the imaging surface. Details of the configuration of the blur correction unit 30 will be described later. FIG. 2 shows a state where the optical axis of the fourth lens unit L4 coincides with the optical axis A2 of the photographing optical system.

  The fifth lens unit L5 is provided on the exit side of the fourth lens unit L4, and moves along the optical axis A2 by a lens driving unit such as a stepping motor (not shown) to change the focal length of the photographing optical system. It is a lens group for.

  The image pickup device 31 is a solid-state image pickup device such as a CCD or a CMOS, for example. The image pickup device 31 is arranged on the exit side of the fifth lens unit L5 and outputs an image pickup signal by subjecting a subject image formed by the photographing optical system to photoelectric conversion.

  The low-pass filter 32 is disposed between the fifth lens unit L5 and the image sensor 31 and prevents the occurrence of moire in the image signal output from the image sensor 31.

  FIG. 3 is an exploded perspective view of the blur correction unit 30. The blur correction unit 30 includes a fixed frame 300, a movable lens frame 301, voice coil motors (VCM) 302 and 303, position detectors 304 and 305, and a steel ball 306.

  The fixed frame 300 is a frame whose position with respect to the optical axis A2 is fixed.

  The movable lens frame 301 is a lens support frame for fixing the fourth lens unit L4 at the center or substantially the center, and is movable with respect to the fixed frame 300 within a plane orthogonal to the optical axis A2. Note that FIG. 3 is described with reference to a state in which the movable lens frame 301 is centered with respect to the fixed frame 300, that is, a state in which the optical axis of the fourth lens unit L4 coincides with the optical axis A2. When viewed from the direction of the optical axis A2, the fixed frame 300 and the movable lens frame 301 have a substantially rectangular length that is longer in the direction perpendicular to the optical axis A1 and the optical axis A2 than in the direction parallel to the optical axis A1. It is formed into a shape.

  The VCMs 302 and 303 are electromagnetic actuators that drive the movable lens frame 301 relative to the fixed frame 300 in a plane orthogonal to the optical axis A2. The arrangement of the two VCMs 302 and 303 is parallel to the short direction of the fixed frame 300 and the movable lens frame 301, and is symmetrical to the line passing through the optical axis of the fourth lens unit L4, toward the object side. It is arranged in a letter C shape. The driving direction D1 of the VCM 302 and the driving direction D2 of the VCM 303 are orthogonal to each other, and both the driving directions D1 and D2 are inclined at 45 degrees with respect to the longitudinal direction of the fixed frame 300 and the movable lens frame 301.

  The VCM 302 includes a VCM coil 3020, a VCM magnet 3021, and VCM yokes 3022 and 3023.

  The VCM coil 3020 is an electric coil fixed to the fixed frame 300 in a state of facing the movable lens frame 301, and is formed in an oval shape having a major axis in a direction orthogonal to the driving direction D1.

  The VCM magnet 3021 is a permanent magnet fixed to the movable lens frame 301 so as to face the VCM coil 3020 fixed to the fixed frame 300.

  The VCM yokes 3022 and 3023 are magnetic bodies formed of, for example, iron-based metal or the like in a plate shape. The VCM yoke 3022 is disposed between the fixed frame 300 and the VCM coil 3020. The VCM yoke 3023 is disposed between the movable lens frame 300 and the VCM magnet 3021.

  The VCM 303 includes a VCM coil 3030, a VCM magnet 3031, and VCM yokes 3032 and 3033, and an ellipse whose major axis is a direction perpendicular to the drive direction D2 of the VCM 303. Except for being formed in a shape, the structure is the same as the VCM 302 described above.

  The position detection units 304 and 305 detect the position of the movable lens frame 301 with respect to the fixed frame 300, that is, the position of the fourth lens unit L4, in a plane orthogonal to the optical axis A2. The two position detectors 304 and 305 are parallel to the short direction of the fixed frame 300 and the movable lens frame 301 and are directed to the object side at positions symmetrical with respect to a line passing through the optical axis of the fourth lens unit L4. It is arranged in a letter C shape.

  The position detection direction D3 of the position detection unit 304 is parallel to the drive direction D2 of the VCM 303. The position detection unit 304 is disposed on a straight line that passes through the optical axis A2 and is parallel to the position detection direction D3.

  The position detection direction D4 of the position detection unit 305 is parallel to the drive direction D1 of the VCM 302. The position detection unit 305 is disposed on a straight line that passes through the optical axis A2 and is parallel to the position detection direction D4.

  Therefore, the position detection direction D3 of the position detection unit 304 and the position detection direction D4 of the position detection unit 305 intersect at the optical axis A2 when the movable lens frame 301 is centered with respect to the fixed frame 300. .

  The position detection unit 304 includes a hall element 3040, a hall element magnet 3041, and a hall element yoke 3042.

  The Hall element 3040 is a magnetic sensor fixed to the fixed frame 300 so as to face the movable lens frame 301, and detects a change in the magnetic field of the Hall element magnet 3041 according to the displacement of the movable lens frame 301 with respect to the fixed frame 300. To do.

  The hall element magnet 3041 is a permanent magnet fixed to the movable lens frame 301 in a state of facing the hall element 3040 of the fixed frame 300.

  The hall element yoke 3042 is a magnetic body formed of, for example, iron-based metal in a plate shape, and is disposed between the movable lens frame 301 and the hall element magnet 3041.

  The position detection unit 305 includes a Hall element 3050, a Hall element magnet 3051, and a Hall element yoke 3052, and has the same structure as the position detection unit 304 described above.

  The steel balls 306a, 306b, and 306c are sandwiched between the fixed frame 300 and the movable lens frame 301, and support the movable lens frame 301 so as to be movable relative to the fixed frame 300 within a plane orthogonal to the optical axis A2. It is a moving body.

  FIG. 4 is a block diagram showing an electrical configuration of the digital camera 1 in the present embodiment. In FIG. 4, the same components as those in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof is omitted. The digital camera 1 includes a lens barrier unit 2, a lens barrel 3, a control unit 5, a storage unit 6, a display unit 7, and an operation unit 8.

  Light from a subject (not shown) is imaged on the image sensor 31 by the photographing optical system of the lens barrel 3. The imaging element 31 outputs an imaging signal obtained by converting a subject image into an electrical signal by photoelectric conversion to the control unit 5. The control unit 5 is composed of an ASIC or the like, and the image signal input to the control unit 5 is subjected to various image processing. The image data converted into a JPEG file or the like as needed is stored in the storage unit 6. The image data processed by the control unit 5 is displayed on a display unit 7 such as a liquid crystal display.

  The shake detection unit 33 is a sensor for detecting a shake such as a movement of the digital camera 1 during image shooting, for example. The blur detection unit 33 includes two angular velocity sensors. One angular velocity sensor detects pitching (rotational motion in the vertical direction), and the other angular velocity sensor detects yawing (rotational motion in the horizontal direction). When the blur detection unit 33 detects the angular velocity information, the blur detection unit 33 outputs a signal of the angular velocity information to the control unit 5. The controller 5 to which the angular velocity information signal is input detects the position of the fourth lens unit L4 by the position detectors 304 and 305. And the control part 5 is a 4th lens required in order to correct | amend blur based on the angular velocity information which the blur detection part 33 detected, and the positional information on the 4th lens group L4 which the position detection parts 304 and 305 detected. The movement amount of the group L4 is calculated, and a signal of the calculation result is output to the VCMs 302 and 303. The VCMs 302 and 303 move the fourth lens unit L4 based on the input signal. Thereby, since the fourth lens unit L4 moves so as to cancel out the blur, the image blur on the imaging surface due to the movement of the digital camera can be reduced.

  The operation unit 8 is a member for a user to input an instruction to the digital camera 1. For example, a power button for turning on or off the power of the digital camera 1, a release for instructing photographing of an image. When a button or any one of up, down, left and right is pressed, it is composed of a cross key for instructing contents corresponding to the pressing direction. When the power source of the digital camera 1 is changed from the OFF state to the ON state when the user presses the power button, the control unit 5 protects the lens barrier 20 from the front surface of the first lens unit L1 of the lens barrel 3. Then, a command is sent to the lens barrier drive motor 22 so as to move to the retracted position where the front surface of the first lens unit L1 of the lens barrel 3 is opened. The lens barrier drive motor 22 that has received the command moves the lens barrier 20 from the protected position to the retracted position by being rotationally driven. At this time, the position detection units 304 and 305 (specifically, the Hall elements 3040 and 3050) detect the state of the protection position and the retracted position of the lens barrier 20. Details of the protection position and the retraction position of the lens barrier 20 and the opening / closing operation thereof will be described later.

  FIG. 5 is a diagram illustrating an output example of the Hall element 3040 with respect to the position of the Hall element magnet 3041 in the position detection unit 304. In FIG. 4, the horizontal axis represents the relative position of the Hall element magnet 3041 with respect to the state where the movable lens frame 301 is centered with respect to the fixed frame 300, and the vertical axis represents the Hall voltage output from the Hall element 3040. .

  The Hall voltage output from the Hall element 3040 is such that the Hall element magnet 3041 is positioned on one side of the detection direction of the Hall element 3040 if the state where the movable lens frame 301 is centered with respect to the fixed frame 300 is zero. If it is located on the other side, it will be negative. Further, as the position of the Hall element magnet 3041 moves away from the state where the movable lens frame 301 is centered with respect to the fixed frame 300, the absolute value of the Hall voltage output by the Hall element 3040 increases.

  In the blur correction unit 30, the Hall elements 3040 and 3050 that detect the position of the fourth lens unit L4 that is displaced in a plane perpendicular to the optical axis A2 are used as detection elements that detect the opening / closing operation of the lens barrier 20. It is also used.

  FIG. 6 is a diagram showing the configuration of the lens barrier 20. The lens barrier 20 is a plate-like member made of a material such as aluminum, and is roughly divided into three parts: a main body part 20a, extending parts 20b and 20d, and bent parts 20c and 20e. The main body 20 a is a portion that covers the front surface of the first lens unit L 1 of the lens barrel 3, that is, a portion that covers the opening 4 a of the digital camera body 4. The size of the main body 20a is configured to be the same as or larger than the size of the opening 4a. The extending portions 20b and 20d and the bent portions 20c and 20e are provided so that the opening / closing operation of the lens barrier 20 can be detected by the Hall elements 3040 and 3050 of the position detectors 304 and 305. The extending part 20b extends outward from the outer periphery of the main body part 20a, and is configured on the same or substantially the same plane as the main body part 20a. The bent portion 20c is a plane in which the tip of the extended portion 20b when viewed from the main body portion 20a side is bent perpendicularly or substantially perpendicular to the lens barrel 3 side with respect to the plane constituting the main body portion 20a and the extended portion 20b. Is configured. The bent portion 20c is configured to generate a magnetic field around the bent portion 20c in order to enable detection by the Hall elements 3040 and 3050. As a method for generating a magnetic field, for example, there is a method in which a magnetic material such as a ferrite magnet or a neodymium magnet is provided in the bent portion 20c, and static magnetic field magnetization or pulse magnetic field magnetization is performed on the magnetic material. As described above, the bent portion 20c is configured to be polarized in two poles in the plane of the bent portion 20c. Instead of magnetizing the bent portion 20c, a magnetic field may be generated by attaching a permanent magnet such as a magnet to the bent portion 20c. At this time, by using a magnet made of a material such as rubber, the thickness in the direction perpendicular to the plane of the bent portion 20c can be suppressed. A yoke or the like may be disposed between the bent portion 20c and the magnet. The extending part 20d and the bent part 20e have the same configuration as the extending part 20b and the bent part 20c.

  FIG. 7 is a diagram illustrating a state in which the lens barrier 20 is stopped at the protection position. The lens barrier 20 stopped at the protection position is disposed so as to cover the front surface of the first lens unit L1 of the lens barrel 3. At this time, the extending portion 20b and the bent portion 20c are located between the Hall element 3040 and the Hall element 3050.

  FIG. 8 is a diagram illustrating a state in which the lens barrier 20 is stopped at the retracted position. The lens barrier 20 stopped at the retracted position is arranged so as to open the front surface of the first lens unit L1 of the lens barrel 3.

  The lengths of the extending portions 20 b and 20 d of the lens barrier 20 are long enough to allow the bent portions 20 c and 20 e at the tips of the extending portions 20 b and 20 d to pass through the lower part of the blur correction unit 30. The lengths of the extending portions 20 b and 20 d are preferably set such that the bent portions 20 c and 20 e are close to the lower portion of the shake correction unit 30 when the lens barrier 20 rotates. Further, the planes that form the bent portions 20c and 20e of the lens barrier 20 are configured to be parallel to the plane of the Hall element 3040 when the bent portions 20c and 20e pass through the lower portion of the Hall element 3040. In the state where the lens barrier 20 is stopped at the protection position or the retracted position, the extending portions 20b and 20d are oriented so that the bent portions 20c and 20e of the lens barrier 20 do not come below the Hall elements 3040 and 3050. ing.

  The detection of the opening / closing operation of the lens barrier 20 will be described.

  When the power of the digital camera 1 is OFF, the lens barrier 20 is stopped at the protected position as shown in FIG. When the power of the digital camera 1 is changed from the OFF state to the ON state, the control unit 5 sends a command to the lens barrier drive motor 22 to move the lens barrier 20 from the protection position to the retracted position. Upon receipt of the command, the lens barrier drive motor 22 starts to rotate, and accordingly, the lens barrier 20 starts to rotate clockwise about the pivot shaft 21. The lens barrier 20 that has started the rotational movement stops at the open position shown in FIG.

  Until the lens barrier 20 reaches the retracted position shown in FIG. 8 from the protection position shown in FIG. 7, the bent portion 20c first passes through the lower part of the Hall element 3040 as shown in FIG. 7, and then the bent portion as shown in FIG. 20e passes below the Hall element 3050 and below the Hall element 3040. Since the bent portion 20c is magnetized as described above, a magnetic field is generated around the bent portion 20c. Therefore, when the bent portion 20 c passes through the lower portion and the lower periphery of the Hall element 3040, the Hall element 3040 detects a change in the strength of the magnetic field and outputs a Hall voltage corresponding to the change to the control unit 5. Similarly, since the bent portion 20e generates a magnetic field around the bent portion 20e, when the bent portion 20e passes through the lower portion and the lower portion of the Hall element 3050, the Hall element 3050 detects a change in the strength of the magnetic field, In response to this, the hall voltage is output to the control unit 5. Similarly, when the bent portion 20 e passes through the lower portion and the lower periphery of the Hall element 3040, the Hall element 3040 detects a change in the strength of the magnetic field and outputs a value of the Hall voltage corresponding to the change to the control unit 5. The control unit 5 calculates the position information of the lens barrier 20 based on the value of the Hall voltage output from the Hall element 3040 and the Hall element 3050. Thereby, the opening / closing operation of the lens barrier 20 can be detected. When the control unit 5 calculates the position information of the lens barrier 20 and determines that the opening / closing operation of the lens barrier 20 is not completed, the control unit 5 causes the lens barrier 20 to complete the opening / closing operation of the lens barrier 20. The drive motor 22 may be commanded.

  Furthermore, the timing for stopping the rotational movement of the lens barrier 20 can be determined based on the Hall voltage output from the Hall element.

Consider a case where the bent portion 20c of the lens barrier 20 passes under the Hall element 3040. The storage unit 7 stores in advance the Hall voltage value V0 output by the Hall element 3040 when the bent portion 20c of the lens barrier 20 passes below the Hall element 3040. When the power of the digital camera 1 is changed from the OFF state to the ON state, the lens barrier 20 starts to move from the protection position to the retracted position, but the Hall element 3040 detects the intensity of the magnetic field generated by the bent portion 20c. The Hall element 3040 that has detected the strength of the magnetic field outputs a Hall voltage value V based on the strength of the magnetic field to the control unit 5. The control unit 5 compares the Hall voltage value V output from the Hall element 3040 with the Hall voltage value V0 read from the storage unit 7. The control unit 5 compares the Hall voltage value V output from the Hall element 3040 with the Hall voltage value V0 read from the storage unit 7. As a result, if V = V0, the bent portion 20c of the lens barrier 20 is It is determined that it is below the Hall element 3040. When the control unit 5 determines that the bent portion 20c of the lens barrier 20 is below the Hall element 3040, the control unit 5 instructs the lens barrier drive motor 22 to stop the rotational movement of the lens barrier 20 after a predetermined time has elapsed since the determination. Output. Thereby, the timing at which the lens barrier drive motor 22 is stopped in accordance with the opening / closing operation of the lens barrier 20 and the rotation amount of the lens barrier drive motor 22 can be optimized. When the opening / closing operation of the lens barrier 20 is detected, the position of the movable lens frame 301 is always constant with respect to the position of the fixed frame 300, for example, the position of the movable lens frame 301 is centered with respect to the position of the fixed frame 300 It is good to be.
(Modification)
Note that the present embodiment can be modified as follows.

  In the position detection units 304 and 305, the Hall elements 3040 and 3050 are used to detect the position of the fourth lens unit L4 in a plane orthogonal to the optical axis A2, but the present invention is not limited to this. Any magnetic sensor capable of detecting the strength of the magnetic field may be used.

  In the shake correction unit 30, the two Hall elements 3040 and 3050 are used to detect the position of the fourth lens unit L4 in a plane orthogonal to the optical axis A2, but the present invention is not limited to this. For example, a blur correction unit that detects the position of the blur correction lens group in a plane perpendicular to the optical axis using three Hall elements may be used.

  The opening / closing operation of the lens barrier 20 is detected by the two Hall elements 3040 and 3050. However, the present invention is not limited to this. For example, one Hall element or three or more Hall elements may be used.

  When the bent part of the lens barrier passes below the Hall element, the polarization direction in the bent part of the lens barrier and the direction of the magnetic field detected by the Hall element should be the same. In the present embodiment, the polarization direction at the bent portion of the lens barrier is in the longitudinal direction of the fixed frame 300, the detection direction D3 of the Hall element 3040 and the detection direction D4 of the Hall element 3050 are orthogonal to each other, and both the detection directions D3 and D4 are Hall elements 3040 and 3050 are arranged so as to be inclined at 45 degrees with respect to the longitudinal direction of the fixed frame 300. For example, the polarization direction at the bent portion of the lens barrier remains the longitudinal direction of the fixed frame 300, and the holes The Hall element 3040 may be arranged so that the detection direction D3 of the element 3040 is in the longitudinal direction of the fixed frame 300, and the detection direction D4 of the Hall element 3050 is in the short direction of the fixed frame 300. At this time, the opening / closing operation of the lens barrier 20 is detected using the Hall element 3040. Further, the detection direction D3 of the Hall element 3040 and the detection direction D4 of the Hall element 3050 are orthogonal to each other, and the detection directions D3 and D4 are both inclined to the longitudinal direction of the fixed frame 300 by 45 degrees. In the state where 3050 is disposed, the polarization direction in the bent portion of the lens barrier may be configured to be inclined by 45 degrees with respect to the longitudinal direction of the fixed frame 300.

  In the shake correction unit 30, the Hall elements 3040 and 3050 that detect the position of the fourth lens unit L4 that is displaced in a plane perpendicular to the optical axis A2 are also used as detection elements that detect the opening / closing operation of the lens barrier 20. However, the detection element for detecting the opening / closing operation of the lens barrier 20 is not limited to this. For example, an optical sensor for detecting the position of a focusing lens group or a zoom lens group that moves along the optical axis of the photographing optical system is used. Also good.

  According to this embodiment described above, the following effects can be obtained.

  In the shake correction unit 30, the Hall elements 3040 and 3050 that detect the position of the fourth lens unit L4 that is displaced in a plane perpendicular to the optical axis A2 are also used as detection elements that detect the opening / closing operation of the lens barrier 20. did. Accordingly, it is not necessary to provide a new detection element for detecting the opening / closing operation of the lens barrier 20, and the number of parts constituting the camera can be reduced and the cost can be reduced. In addition, since a space for providing a new detection element is not required, the camera can be reduced in size.

  The opening / closing operation of the lens barrier is performed when no image is taken, for example, when the digital camera 1 is turned on or off, or when the digital camera 1 is turned on and there is no operation on the digital camera 1 for a predetermined time. In addition, when the lens barrier is opened and closed, the position of the movable lens frame 301 with respect to the position of the fixed frame 300 is always constant, for example, the position of the movable lens frame 301 is centered with respect to the position of the fixed frame 300. did. Thereby, there is no influence other than the change of the magnetic field accompanying the opening / closing operation of the lens barrier, and the Hall element can accurately detect the opening / closing operation of the lens barrier.

  The bent portions 20 c and 20 e of the lens barrier 20 are configured to pass through the space below the blur correction unit 30. This eliminates the need to cut out the lens barrel 3.

  In the first embodiment, a digital camera has been described as an example of an optical device. However, the present invention is not limited to this. For example, a film camera, a video camera, a binocular, or the like may be used.

It is a perspective view which shows the external appearance of the lens barrier unit 2 and the lens-barrel 3 in 1st Embodiment of this invention. It is sectional drawing of the right side surface of the digital camera 1 in 1st Embodiment of this invention. It is a disassembled perspective view of the blurring correction unit 30 in the first embodiment of the present invention. 1 is a block diagram showing an electrical configuration of a digital camera 1 in a first embodiment of the present invention. It is a figure which shows the example of an output of the Hall element 3040 with respect to the position of the magnet 3041 for Hall elements in 1st Embodiment of this invention. It is the figure which showed the structure of the lens barrier 20 in 1st Embodiment of this invention. It is the figure which showed the state which has the lens barrier 20 in 1st Embodiment of this invention in a protection position. It is the figure which showed the state which has the lens barrier 20 in 1st Embodiment of this invention in a retracted position.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Digital camera 2 Lens barrier unit 20 Lens barrier 20a Main body part 20b, 20d Extension part 20c, 20e Bending part 21 Pivot shaft 22 Lens barrier drive motor 23 Lens barrier drive lever 3 Lens barrel 30 Shake correction unit 300 Fixed frame 301 Movable lens frame 302, 303 Voice coil motor 3020, 3030 VCM coil 3021, 3031 VCM magnet 3022, 3032 VCM yoke 3023, 3033 VCM yoke 304, 305 Position detection unit 3040, 3050 Hall element 3041, 3051 For Hall element Magnet 3042, 3052 Hall element yoke 306 Steel ball 31 Image sensor 32 Low-pass filter 33 Blur detection unit 4 Camera body 4a Opening 5 Control unit 6 Storage unit 7 Display unit Operation unit L1 first lens group L2 second lens unit L3 third lens unit L4 fourth lens group L5 fifth lens group P prisms

Claims (10)

An optical system including a movable lens;
A lens protector that is movable between a protective position that covers the front surface of the optical system and a retracted position that exposes the front surface of the optical system;
A detection unit for detecting the position of the lens,
The optical device, wherein the detection unit also detects a position of the lens protection unit. The optical instrument according to claim 1,
The lens is a blur correction lens that corrects blur by moving a plane perpendicular to the optical axis of the optical system,
The optical device, wherein the detection unit detects a position of the lens in a plane perpendicular to an optical axis of the optical system. The optical apparatus according to claim 2,
The optical device, wherein the detection unit is a magnetic sensor capable of detecting the intensity of a magnetic field in a specific direction. The optical apparatus according to claim 3.
The lens protection unit includes a magnetization region polarized into an N pole and an S pole,
2. The optical apparatus according to claim 1, wherein the magnetic sensor detects a position of the lens protection unit by detecting a magnetic field in the magnetization region that changes as the lens protection unit moves. The optical apparatus according to claim 4,
An optical apparatus, wherein a direction in which the magnetic sensor can detect the intensity of a magnetic field is parallel to a direction polarized to the N pole and the S pole of the magnetization region. The optical apparatus according to claim 5, wherein
The optical apparatus according to claim 1, wherein the magnetized region is provided on a surface of the lens protection unit that is bent perpendicularly to a plane that forms the lens protection unit. The optical apparatus according to claim 6, wherein
The optical sensor detects the magnetic field of the magnetization region when the magnetization region is positioned so as to face the magnetic sensor. In the optical instrument according to any one of claims 1 to 7,
A control unit for controlling the movement between the protection position and the retracted position of the lens protection unit;
The control unit stops the movement of the lens protection unit based on the output of the detection unit. In the optical instrument according to any one of claims 1 to 8,
The optical apparatus includes a reflection unit that bends the optical axis of subject light, and is a bending optical system that forms a subject image. In the optical instrument according to any one of claims 1 to 9,
The optical apparatus is a camera.

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