JP2009086494A - Initial position setting method for camera-shake correction unit, lens barrel and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an initial position setting method for a camera-shake correction unit for making the image circle center of an imaging optical system nearly align with the imaging center of an imaging element, and to obtain a lens barrel and an imaging apparatus where the initial position of the imaging element is accurately set. <P>SOLUTION: The initial position setting method for a camera-shake correction unit includes an imaging device moving mechanism for moving the imaging device in a plane perpendicular to the optical axis of the imaging optical system, and a sensor for detecting the position of a moving member that moves integrally with the imaging device, and further includes: a step of moving the moving member to a prescribed position; a step of moving a frame member that holds the moving lens groups of the imaging optical system toward the imaging device side beyond the photographing area, and fitting a shaft-like part formed on the frame member to a hole part formed in the moving member; and a step of, after the step, setting the output of the sensor at the position of the moving member as the initial position. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for setting an initial position of a camera shake correction unit, a lens barrel including the camera shake correction unit, and an imaging apparatus.

  2. Description of the Related Art Conventionally, in a digital camera, a camera shake correction technique for correcting a deviation of an image due to camera shake during shooting and obtaining a clear image has been put into practical use. Among the camera shake correction techniques, optical correction methods include a correction method by moving a part of the imaging optical system, a correction method by moving the image sensor, and a method of moving the entire imaging optical system.

Among these, for example, an imaging apparatus described in Patent Document 1 below is known as a camera shake correction that is performed by moving an imaging element.
JP 2003-110929 A

  The camera shake correction unit described in Patent Document 1 has a sufficient camera shake correction effect. In camera shake correction, it is necessary to move the image sensor in accordance with the direction and speed of camera shake, but it is preferable to position the image sensor in the center of the image circle in a state before photographing. This is because an area in which the image sensor can be moved within the image circle regardless of the direction of camera shake is ensured.

  On the other hand, in a lens barrel in which an image pickup optical system and a camera shake correction unit are assembled for the first time, there is no confirmation whether the image pickup element is located at the center of the image circle. The position was set to the initial position.

  However, in this method, there are many cases where many parts are interposed between the predetermined part and the image sensor, and a position other than the center of the image circle is set as the initial position due to accumulation of part errors.

  In view of the above problems, the present invention provides an initial position setting method for a camera shake correction unit in which the center of an image circle of an image pickup optical system and the image pickup center of an image pickup element substantially coincide with each other, and a lens mirror in which the initial position of the image pickup element is accurately set The object is to obtain a barrel and an imaging device.

  The above object is achieved by the invention described below.

  1. Initial position setting of an image stabilization unit including an image sensor moving mechanism that moves an image sensor within a plane orthogonal to the optical axis of the image pickup optical system and a sensor that detects the position of a moving member that moves integrally with the image sensor A method of moving the moving member to a predetermined position, and moving a frame member holding the moving lens group of the imaging optical system to a position on the imaging element side beyond a region used for photographing. A step of fitting the shaft-shaped portion formed on the frame member and the hole formed on the moving member, and after the step, the output of the sensor at the position of the moving member is set to an initial position A method for setting an initial position of a camera shake correction unit.

  2. An imaging optical system having a moving lens group that moves in the optical axis direction, an imaging device that photoelectrically converts a subject image formed by the imaging optical system, and an in-plane that is orthogonal to the optical axis of the imaging optical system In a lens barrel having an image sensor moving mechanism that moves the image sensor and a camera shake correction unit that detects a position of a moving member that moves integrally with the image sensor, the lens barrel moves integrally with the image sensor. The moving member is formed with a hole, and the frame member that holds the moving lens group is formed with a shaft-like portion that fits into the hole, and the hole is the center of the imaging region of the imaging element. Is formed at a position that matches the optical axis of the imaging optical system and is fitted to the shaft-shaped portion.

  An imaging apparatus comprising the lens barrel described in 3.2.

  According to the present invention, it is possible to obtain an initial position setting method of a camera shake correction unit in which the center of an image circle of an image pickup optical system and the image pickup center of an image pickup element substantially coincide with each other, and a lens in which the initial position of the image pickup element is set accurately. A lens barrel and an imaging device can be obtained.

  Hereinafter, the present invention will be described in detail by embodiments, but the present invention is not limited thereto.

  FIG. 1 is a diagram illustrating an example of an internal arrangement of main component units of the imaging apparatus 100 according to the present embodiment. FIG. 3 is a perspective view of the imaging apparatus 100 as viewed from the subject side.

  As shown in the figure, in the imaging apparatus 100, a lens barrel 50 including a bending imaging optical system capable of zooming is arranged as shown in the figure, and an opening 51 is arranged to take in a subject light beam. The opening 51 is provided with a lens barrier (not shown) that is in an open state that exposes the opening 51 and a closed state that covers the opening 51.

  Reference numeral 52 denotes a flash light emission window. Reference numeral 53 denotes a flash unit including a reflector, a xenon tube, other main capacitors, a circuit board, and the like disposed behind the flash light emission window. Reference numeral 54 denotes a card-type image recording memory. A battery 55 supplies power to each unit of the imaging apparatus. The image recording memory 54 and the battery 55 can be inserted and removed from a lid (not shown).

  A release button 56 is disposed on the upper surface of the imaging apparatus 100, and a shooting preparation operation, that is, a focusing operation and a photometry operation are performed by pressing the first step, and a shooting exposure operation is performed by pressing the second step. . A main switch 57 is a switch for switching the imaging apparatus between an operating state and a non-operating state. When switched to the operating state by the main switch 57, the lens barrier (not shown) is opened and the operation of each part is started. When the main switch 57 is switched to the non-operating state, the lens barrier (not shown) is closed and ends the operation of each unit.

  On the back surface of the imaging apparatus 100, an image display unit 58 that is configured by an LCD, an organic EL, or the like and displays an image, other character information, or the like is disposed. Although not shown, a zoom button for zooming up and down, a playback button for playing back a captured image, a menu button for displaying various menus on the image display unit 58, and a desired function are selected from the display. An operation member such as a selection button is arranged.

  Although not shown, each part is connected between these main constituent units and a circuit board on which various electronic components are mounted is arranged to drive and control each main constituent unit. Yes. Similarly, although not shown, an external input / output terminal, a strap attaching portion, a tripod seat, and the like are provided.

  In the present embodiment, description is made using a bending imaging optical system capable of zooming. However, an imaging optical system in which the optical axis is not bent, a single-focus imaging optical system, or the like may be used.

  FIG. 2 is a block diagram illustrating an overview of the imaging apparatus 100 according to the present embodiment.

  As shown in the figure, the imaging optical system 40 in the lens barrel 50 is configured to move a predetermined lens group by the first motor 20 and the second motor 21 and is subjected to zooming and focus adjustment. . Further, in the lens barrel 50, two actuators 61 for moving the image sensor 6 in a direction to cancel the image movement in the yaw direction and the pitch direction shown in FIG. The image sensor 6 is moved by the first drive actuator 61P and the second drive actuator 61Y. Note that the independent first and second drive actuators 61P and 61Y constituting the actuator 61 do not have to match the pitch direction and the yaw direction, and the image is taken in an arbitrary direction by combining the two actuators. What is necessary is just to be able to move an element.

  Further, a sensor 62 is provided for detecting the moving position of the image sensor 6 by the actuator 61. The position in the pitch direction is determined by the pitch direction position sensor 62P, and the position in the yaw direction is determined by the yaw direction position sensor 62Y. Note that the outputs of the pitch direction position sensor 62P and the yaw direction position sensor 62Y at the initial position of the image sensor 6 are stored in the EEPROM 83.

  The actuator 61 is driven by a driver 63 controlled by the control unit 30. The first motor 20 and the second motor 21 are also driven by drivers 22 and 23 controlled by the control unit 30, respectively.

  A shake detection sensor 64 that detects the shake detects the shake of the lens barrel 50. Specifically, the shake detection sensor 64P detects an angular velocity in the pitch direction (specifically, an inertial angular velocity (ground angular velocity)), and the shake detection sensor 64Y detects an angular velocity in the yaw direction.

  The signals from the shake detection sensors 64P and 64Y are amplified and filtered by the shake detection circuit 65, detected as a signal indicating “shake”, and input to the control unit 30 constituted by, for example, a microcomputer. It has become.

  In the control unit 30, a predetermined software program stored in the ROM 81 is executed using a RAM (not shown) as a work area, and functions of the respective units are executed. For example, the control output unit 35 obtains the current angle in the pitch direction and the yaw direction based on the signal from the shake detection circuit 65, and outputs the output value of the servo control system that reduces the difference between the current angle and the target angle. Ask. That is, a control command value for driving the image pickup device 6 to move in the plane is generated so as to suppress the shake detected by the shake detection circuit 65. The control output unit 35 outputs the generated control command value to the driver 63.

  The driver 63 drives the first drive actuator 61P and the second drive actuator 61Y based on the control command value. As a result, the image sensor 6 is displaced in-plane, and the camera shake is corrected. The pitch direction position sensor 62 </ b> P and the yaw direction position sensor 62 </ b> Y are sensors for detecting the position of the image sensor 6 driven in-plane by the actuator 61 and feedback-controlling the displacement drive of the image sensor 6.

  The EEPROM 82 is storage means for storing adjustment data related to control of camera shake correction in addition to individual data such as a zoom position at the time of zooming of the image pickup optical system 40 and an infinite focus position of the focus lens.

  In addition, the imaging apparatus 100 is provided with a signal processing unit 71, an A / D conversion unit 72, an image processing unit 73, and an image memory 74 as processing units that handle images obtained by the imaging element 6. The image of the analog signal acquired by the image sensor 6 is A / D converted by the A / D converter 72 via the signal processor 71 and subjected to predetermined image processing by the image processor 73, and then temporarily stored in the image memory 74. Stored. The image stored in the image memory 74 is recorded on the memory card 54 as a recording image, or displayed on the image display unit 58 as a live view display image by performing a desired process.

  An operation switch group 150 such as a cross key button, a zoom operation button, a mode selection dial, and a mode setting button group is connected to the control unit 30, and the imaging apparatus 100 is operated based on the operation by a user operation. ing.

  Hereinafter, the lens barrel 50 will be described in more detail.

  FIG. 3 is a cross-sectional view of the lens barrel 50 according to the present embodiment. This figure is a cross-sectional view of a surface including the optical axis OA before bending and the optical axis OB after bending.

  In the figure, reference numeral 1 denotes a first lens group. The first lens group 1 is a prism 11 that is a reflection member that bends the optical axis OA in a substantially right angle direction with a lens 11 that is arranged toward the subject with an optical axis of OA. 12 and a lens 13 arranged with the optical axis OB bent by the prism 12 as an optical axis. The first lens group 1 is a lens group fixed to the main body 10.

  Reference numeral 2 denotes a second lens group, which is incorporated in the second lens group frame 2k. The second lens group 2 is a lens group that moves integrally with the second lens group lens frame 2k during zooming (hereinafter also referred to as zooming).

  Reference numeral 3 denotes a third lens group, which is fixed to the main body 10. The third lens group 3 is a lens group that does not move.

  S is a unit having at least one of an aperture and a shutter. This unit S is fixed to the main body 10.

  Reference numeral 4 denotes a fourth lens group, which is incorporated in the fourth lens group frame 4k. The fourth lens group is a lens group that moves integrally with the fourth lens group lens frame 4k at the time of zooming, and also moves alone to perform focus adjustment (hereinafter also referred to as focusing).

  The second lens group 2 and the fourth lens group 4 are located far away from the third lens group 3 at a wide angle, and move in a direction approaching the third lens group 3 with zooming to the long focal point side. To do.

  Reference numeral 5 denotes an optical filter in which an infrared light cut filter and an optical low-pass filter are stacked. Reference numeral 6 denotes an image sensor, which uses a charge coupled device (CCD) type image sensor, a complementary metal-oxide semiconductor (CMOS) type image sensor, or the like.

  The image sensor 6 is held by an image sensor holding plate 41. The moving plate 42 that is integral with the image sensor holding plate 41 and has a gap is mounted on the actuator 61 on the base plate 43 in a state that it can move in a plane orthogonal to the optical axis OB. ing. By the actuator 61, the moving plate 42, the image sensor holding plate 41, and the image sensor 6 are integrally moved in a plane perpendicular to the optical axis OB.

  The first drive actuator 61P, the second drive actuator 61Y, the pitch direction position sensor 62P, and the yaw direction position sensor 62Y are connected to the flexible printed circuit board FPC1. The image sensor 6 is connected to a flexible printed circuit board FPC2.

  As illustrated, a gap is formed between the imaging element holding plate 41 and the moving plate 42 on the back side of the imaging element 6, and the flexible printed circuit board FPC 2 connected to the imaging element 6 has a slack in this gap. Are arranged. By doing in this way, even if the image pick-up element 6 moves at the time of camera shake correction, the resistance load at the time of the movement by a board | substrate can be reduced.

  Hereinafter, the image sensor moving mechanism of the lens barrel 50 will be described.

  FIG. 4 is an exploded perspective view showing a structure of a camera shake correction unit 90 having an image sensor moving mechanism attached to the lens barrel 50 according to the present embodiment.

  As shown in the figure, a first drive actuator 61P, which is a drive means for moving the image sensor, is fixed to the base plate 43 using two bent portions 43k, and the first drive actuator 61P is connected to the slider 66. Is engaged.

  A second driving actuator 61Y, which is a driving means for moving the image sensor, is fixed to the moving plate 42 using two bent portions 42k, and the second driving actuator 61Y is also engaged with the slider 66.

  The slider 66 can be displaced relative to each actuator in the axial direction of the actuator, and the relative position of the moving plate 42 with respect to the base plate 43 can be changed by controlling the driving of each actuator. ing. Thereby, the image pickup device 6 assembled integrally with the moving plate 42 is moved in a plane orthogonal to the optical axis to perform camera shake correction.

  In addition, the image sensor holding plate 41 is fixed to the moving plate 42 through two columnar members 67 and 68. A hole 41 h is formed in the image sensor holding plate 41. When the hole 41h is fitted with a shaft-shaped part formed in a fourth lens group lens frame 4k, which will be described later, the center of the imaging area of the imaging element 6 matches the optical axis of the imaging optical system. It is formed in the position to do.

  Both the first drive actuator 61P and the second drive actuator 61Y are formed by attaching a weight to one end of a piezoelectric element that expands and contracts when energized, and a shaft member to the other end. The slider 66 is engaged with a desired frictional force applied to the shaft member. By changing and controlling the speeds of the first and second drive actuators 61P and 61Y in the extending direction and the contracting direction, the inertial force causes slippage between the shaft member and the slider 66, thereby changing the relative position of the shaft member and the slider 66. Thus, the moving plate 42, that is, the image sensor 6 is slid with respect to the base plate 43 to perform camera shake correction.

  Further, the moving plate 42 is provided with a magnet 62m that constitutes a position sensor 62 that detects the position of the image sensor 6. The hall element 62h constituting the position sensor 62 is connected to the printed circuit board FPC1 and is integrally fixed to the base plate 43.

  Note that SP is a tension coil spring that prevents the base plate 43 and the image sensor holding plate 41 from being separated from each other.

  With the above configuration, the camera shake correction unit 90 can slide the image sensor 6 with respect to the base plate 43 by driving the first and second drive actuators 61P and 61Y. Further, the magnet 62m assembled to the moving plate 42 also moves integrally, and the position of the image sensor 6 can be detected by detecting this movement with the hall element 62h. That is, the magnet 62m and the hall element 62h correspond to the pitch direction position sensor 62P and the yaw direction position sensor 62Y shown in FIG.

  FIG. 5 is a schematic diagram showing a configuration after the second lens group of the lens barrel 50 according to the present embodiment.

  As shown in the figure, a guide shaft 15 is provided through a sleeve 2s formed integrally with the second lens group frame 2k and a sleeve 4s formed integrally with the fourth lens group frame 4k. It has been. Further, the guide shaft 16 engages with a rotation locking portion 2m formed integrally with the second lens group lens barrel 2k and a rotation locking portion 4m formed integrally with the fourth lens group lens frame 4k. Is provided. Thereby, the second lens group lens frame 2k and the fourth lens group lens frame 4k are slidable along the guide shafts 15 and 16 in the direction of the optical axis OB.

  As shown in the figure, a convex portion 4t is integrally formed on the fourth lens group lens frame 4k on the side of the camera shake correction unit 90, and a shaft-shaped portion 4p is formed at the tip of the convex portion 4t. The outer diameter of the shaft-shaped portion 4p is formed so as to be fitted to the inner diameter of the hole 41h formed in the image sensor holding plate 41. Further, as shown in the drawing, a tapered portion is formed at the tip. .

  A female screw member 30 (hereinafter referred to as a nut) is screwed to a lead screw 20r that is a male screw member formed on the rotating shaft of the first motor 20 that is a stepping motor. Although not shown, the nut 30 is rotationally locked, and can be moved by the rotation of the first motor 20, that is, the rotation of the lead screw 20r. A compression coil spring 18 is disposed inside the nut 30, and the nut 30 is engaged by a U-shaped portion formed in the sleeve portion 2 s. Thereby, the second lens group 2 moves along the guide shafts 15 and 16 by the movement of the nut 30.

  Similarly, a female screw member 31 (hereinafter referred to as a nut) is screwed into a lead screw 21r that is a male screw member formed on the rotation shaft of the second motor 21 that is a stepping motor. The nut 31 is engaged with a U-shaped portion formed on the sleeve portion 4s. As a result, the fourth lens group 4 moves along the guide shafts 15 and 16 by the movement of the nut 31.

  At the time of shooting, the second lens group 2 in the second lens group frame 2k is moved within the region indicated by C from the position shown to the broken line, and the fourth lens group 4 in the fourth lens group frame 4k is It is set so that it can be moved within a region indicated by D between two broken lines in the figure. In the region D, the shaft-like portion 4p is set apart from the hole portion 41h, and is set so as not to interfere with a member of the camera shake correction unit 90 that moves for camera shake correction.

  In the camera shake correction unit 90 of the lens barrel 50 as described above, a method of setting the position where the center of the imaging area of the imaging device 5 matches the optical axis of the imaging optical system as the initial position of the sensor output will be described.

  FIG. 6 is a flowchart showing an operation for setting the sensor output to the initial position when the camera shake correction unit 90 is assembled to the main body 10.

  In the flow shown in the figure, first, when the camera shake correction unit 90 is assembled to the main trunk 10, first, the moving plate 42, the image sensor holding plate 41, the image sensor, which are integrally configured, are moving members. 6 and the optical filter 5 are moved to predetermined positions (step S101). The predetermined position may be a position where the center of the shaft-like portion 4p overlaps with the hole 41h. For example, the predetermined position is moved using the position of the corner of the moving plate 42 as a guide.

  Thereafter, the second motor 21 is driven to start moving the fourth lens group frame 4k in the direction of the image sensor beyond the region D used for photographing (step S102).

  Next, it is determined whether the fourth lens group frame 4k has moved by a predetermined amount (step S103). The amount of movement of the fourth lens group frame 4k is determined by driving the second motor 21 with an initial position at which a part of the fourth lens group frame 4k crosses a photo sensor such as a photo interrupter or a photo reflector (not shown). It is controlled by the number of steps. Whether or not it has moved by a predetermined amount is determined by whether or not a predetermined number of steps have been driven from a position crossing the photosensor.

  If it is determined that the fourth lens group lens frame 4k has moved by a predetermined amount (step S103; Yes), the second motor 21 is stopped and the movement of the fourth lens group lens frame 4k is stopped (step S104).

  FIG. 7 is a diagram illustrating a state of the lens barrel 50 when step S104 is reached in the flowchart illustrated in FIG.

  As shown in the figure, the fourth lens group lens frame 4k is moved to the image sensor unit 90 side from the region indicated by D used for photographing, and the shaft-like portion 4p is inserted into the hole 41h to be in a fitted state. It becomes. At this time, when the shaft-like portion 4p and the hole portion 41h are not accurately positioned, the moving plate 42, the image sensor holding plate 41, and the image sensor that are integrated by the taper portion of the shaft-like portion 4p. 6 is moved, and the shaft-like portion 4p and the hole portion 41h are brought into a fitted state as shown in the figure. The position of the shaft-like portion 4p and the hole portion 41h is formed so that the center of the imaging region of the imaging device 6 matches the optical axis of the imaging optical system when fitted. The center of the imaging region and the optical axis of the imaging optical system are matched. Thereby, the center of the image circle of the imaging optical system coincides with the imaging center of the imaging device.

  Returning to the flow of FIG. 6, in the state shown in FIG. 7, the output values of the magnet 62m and the hall element 62h as the pitch direction position sensor 62P and the yaw direction position sensor 62Y are set and stored as initial positions (step S105). The output value at the initial position is stored in the EEPROM 83 shown in FIG.

  Thereafter, the second motor 21 is driven, and the fourth lens group frame 4k is returned to the area indicated by D used for photographing (step S106), and the initial position setting is completed.

  Through the above-described steps, the initial position of the camera shake correction unit 90 can be set to a position where the center of the image circle of the imaging optical system and the imaging center of the imaging device 6 substantially coincide. Thereby, it is possible to obtain a lens barrel in which the imaging center of the imaging device 6 is accurately set at the center of the image circle at the initial position.

  In the present embodiment, the image sensor holding plate corresponds to a moving member, but the member forming the hole is not limited to this, and is a member that can be moved integrally with the image sensor. If there is, it has the same effect.

  In addition, the actuator using the piezoelectric element as an actuator of the image sensor moving mechanism in the camera shake correction unit has been described as an example, but the present invention is not limited to this, and the image sensor moving mechanism using a voice coil motor or a stepping motor is also described. Applicable. Furthermore, the imaging optical system having a four-group configuration has been described as an example, but it goes without saying that the present invention is not limited to this.

It is a figure which shows an example of the internal arrangement | positioning of the main structural unit of the imaging device which concerns on this Embodiment. It is a block diagram which shows the outline | summary of the imaging device which concerns on this Embodiment. It is sectional drawing of the lens barrel which concerns on this Embodiment. It is a disassembled perspective view which shows the structure of the camera-shake correction unit which has an image pick-up element moving mechanism attached to the lens barrel which concerns on this Embodiment. It is a schematic diagram which shows the structure after the 2nd lens group of the lens barrel which concerns on this Embodiment. It is a flowchart which shows the operation | movement for setting a sensor output to an initial position when a camera shake correction unit is assembled | attached to the main cylinder. It is a figure which shows the state of a lens barrel when it becomes step S104 in the flowchart shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st lens group 2 2nd lens group 2k 2nd lens group frame 3 3rd lens group 4 4th lens group 4k 4th lens group frame 4p Axis part 4t Convex part 5 Optical filter 6 Imaging element 10 Main trunk 15, 16 Guide shaft 20 First motor 21 Second motor 30, 31 Female screw member 41 Image sensor holding plate 41h Hole 42 Moving plate 43 Base plate 62h Hall element 62m Magnet 66 Slider 71 Holding member 90 Camera shake correction unit 50 Lens mirror Body 100 Imaging device

Claims (3)

Initial position setting of an image stabilization unit including an image sensor moving mechanism that moves an image sensor within a plane orthogonal to the optical axis of the image pickup optical system and a sensor that detects the position of a moving member that moves integrally with the image sensor A method,
Moving the moving member to a predetermined position;
A frame member that holds the moving lens group of the imaging optical system is moved to a position on the imaging element side beyond an area used for photographing, and is formed on the shaft-like portion formed on the frame member and the moving member. A step of fitting the open hole,
After the step, there is a step of setting an output of the sensor at the position of the moving member to an initial position. An imaging optical system having a moving lens group that moves in the optical axis direction, an imaging device that photoelectrically converts a subject image formed by the imaging optical system, and an in-plane that is orthogonal to the optical axis of the imaging optical system In a lens barrel having an image pickup device moving mechanism that is moved at a position and a camera shake correction unit that includes a sensor that detects a position of a moving member that moves integrally with the image pickup device,
A hole is formed in the moving member that moves integrally with the imaging element, and a shaft-like portion that fits into the hole is formed in the frame member that holds the moving lens group,
The lens barrel, wherein the hole portion is formed at a position where the center of the imaging region of the imaging element coincides with the optical axis of the imaging optical system and is fitted with the shaft-like portion. An imaging apparatus comprising the lens barrel according to claim 2.

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