JP2008197354A - Lens drive unit and optical apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens drive unit that can be made more compact by reducing the disposition area of a member on a plane perpendicular to the lens driving direction. <P>SOLUTION: The lens drive unit includes: driving means 12, 13, and 14, by which a lens holder 7 holding the lens L3 is driven in the direction of the optical axis of the lens L3; weights 11b and 12 functioning as counter balance for the lens holder 7; and a lever 11 having an acting point 11c on which the lens holder 7 abuts and an operating point 11b to which the weights 11b and 12 are attached, connecting the lens holder 7 and weights 11b and 12, and disposed so as to be turnable in a direction perpendicular to the optical axis of the lens L3. The turning axial line of the lever 11 is disposed in a position intersecting the optical path of the lens L3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lens driving device mounted on an optical device such as a camera and an optical device including the lens driving device.

  As a conventional lens driving device, there is one using a counter balance weight (hereinafter referred to as a weight) (Patent Document 1).

  This lens driving device includes a lens movable body having an objective lens, and a focus adjustment drive magnetic circuit that drives the lens movable body in a focus direction that is an optical axis direction of the objective lens.

  The lens driving device also includes a tracking adjustment driving magnetic circuit that drives the movable lens body in a tracking direction that is orthogonal to the optical axis of the objective lens, and a weight that functions as a counter balance of the movable lens body. Prepare.

The focus adjustment drive magnetic circuit and the tracking adjustment drive magnetic circuit are arranged on the weight side, and the weight functions as a counter balance of the movable lens body in both the focus direction and the tracking direction.
Japanese Patent Laid-Open No. 9-44872

  However, in Patent Document 1, since the lens, lever, and weight are developed and arranged on a plane perpendicular to the lens driving direction, the arrangement area of the members on the plane perpendicular to the lens driving direction becomes large. There is.

  Also, if the lens moving distance is long, the amount of deflection at the operating point on the opposite side of the lever fulcrum increases, so there is a need to secure a retracting space so as not to interfere with the lever on the operating point side, and the size of the actuator increases. There is a problem to do.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a lens driving device and an optical apparatus that can be reduced in size by reducing the arrangement area of members on a plane perpendicular to the lens driving direction.

  In order to achieve the above object, a lens driving device of the present invention functions as a lens holder that holds a lens, a driving unit that drives the lens holder in the optical axis direction of the lens, and a counterbalance of the lens holder. It has a weight, an action point where the lens holder abuts, and an operating point where the weight is attached, and connects the lens holder and the weight and rotates in a direction perpendicular to the optical axis of the lens. And a lever arranged so as to be capable of being disposed at a position where the rotation axis of the lever crosses the optical path of the lens.

  An optical apparatus according to the present invention includes the lens driving device according to any one of claims 1 to 5.

  According to the present invention, it is possible to arrange the lens and the lever so as to be folded on a plane perpendicular to the optical axis of the lens by arranging the axis of the pivot point of the lever at a position crossing the optical path of the lens. .

  As a result, the arrangement area of the members on a plane perpendicular to the lens driving direction can be reduced and the size can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, with reference to FIGS. 1-6, the lens drive device which is the 1st Embodiment of this invention is demonstrated.

  FIG. 1 is a cross-sectional view for explaining the internal structure of a camera equipped with a lens driving device according to a first embodiment of the present invention in a lens barrel storage state, and FIG. It is sectional drawing for demonstrating the internal structure in imaging | photography state.

  FIG. 3 is a cross-sectional view for explaining the internal structure in a photographing state in which the third group lens L3 is in the extended position, and FIG. 4 is an external perspective view of the camera.

  As shown in FIG. 4, a retractable lens barrel 2 is provided in front of the camera 1.

  As shown in FIG. 1, the lens barrel 2 includes a first group lens L1, a second group lens L2, and a third group lens L3, and adjusts the focus by moving the third group lens L3 in the optical axis direction. 2 and 3, the optical path of the third lens unit L3 is indicated by a one-dot chain line.

  The first group lens L1 is held by a first group lens holder 3 having a first group cam pin 3a, and the second group lens L2 is held by a second group lens holder 4 having a second group cam pin 4a and a shutter unit 4b.

  A cam cylinder 5 and a fixed cylinder 6 are arranged on the outer peripheral side of the first group lens holder 3 and the second group lens holder 4.

  The cam cylinder 5 rotates about the optical axis, a gear portion 5a is provided on the outer peripheral portion, and a first group cam groove 5b and a second group cam groove 5c are provided on the inner peripheral portion.

  The fixed cylinder 6 has a cam cylinder 5 rotatably fitted on the outer peripheral portion, and three circumferentially extending through holes 6a extending in the optical axis direction are spaced apart from each other in the circumferential direction. The first group cam pin 3a and the second group cam pin 4a are fitted in the rectilinear groove 6a so as to be movable in the optical axis direction.

  Next, the operation of the retractable barrel 2 will be described.

  When a drive gear (not shown) connected to the gear portion 5 a of the cam cylinder 5 rotates, the cam cylinder 5 rotates around the fixed cylinder 6.

  When the cam cylinder 5 rotates, the first group cam pin 3a that engages with the first group cam groove 5b on the inner peripheral side of the cam cylinder 5 is guided by the rectilinear groove 6a along the lift of the first group cam groove 5b, and the optical axis direction Move to.

  Similarly, when the cam cylinder 5 rotates, the second group cam pin 4a engaged with the second group cam groove 5c on the inner peripheral side of the cam cylinder 5 is guided by the rectilinear groove 6a along the lift of the second group cam groove 5c. Move in the direction of the optical axis.

  In this way, the first group lens holder 3 and the second group lens holder 4 move in the optical axis direction, so that the first group lens L1 and the second group lens L2 are moved from the housed state shown in FIG. 1 to FIGS. Move to the shooting state shown.

  Next, a lens driving device that moves the third lens group L3 forward and backward in the optical axis direction will be described with reference to FIGS.

  FIG. 5 is a perspective view showing the lens driving device with the third group lens L3 in the retracted position, and FIG. 6 is a perspective view showing the lens driving device with the third group lens L3 in the extended position.

  As shown in FIG. 5, the lens driving device includes a third lens group holder 7 for holding the third lens group L3, a CCD lens holder 8 having a fulcrum shaft 8a, and a ring-shaped lever 11 arranged so as to surround the optical axis. Prepare.

  The third group lens holder 7 is provided with a sleeve 7a, a steadying portion 7b, a contact portion 7c, and a position detecting portion 16.

  The CCD lens holder 8 holds a guide bar 9 and a steady bar 10. The CCD lens holder 8 is provided with a yoke 13, a magnet 14, and a scale 15.

  The lever 11 has a pair of fulcrum bearings 11a at positions facing each other in the radial direction on the ring circumference. In the lever 11, an operating point 11b is arranged on the ring circumference at an intermediate position between the pair of fulcrum bearings 11a, and an action point 11c is arranged on the ring circumference opposed to the operating point 11b in the radial direction.

  The fulcrum bearing 11a is fitted to the fulcrum shaft 8a of the CCD lens holder 8 and supports the lever 11 so as to be rotatable about an axis line disposed at a position orthogonal to the optical axis of the third lens unit L3 and across the optical path.

  The abutting portion 7c of the third group lens holder 7 is urged so as to abut on the action point 11c by a presser spring 11d formed of an elastic member or the like.

  A coil 12 is wound around the operating point 11 b via an air core 12 a, and the coil 12 and the operating point 11 b function as a counter balance weight for the third group lens holder 7.

  A focus FPC (flexible printed circuit board) 17 is attached to the side peripheral surface of the lever 11, one end of the focus FPC 17 is connected to the coil 12, and the other end is connected to the position detection unit 16.

  The focus FPC 17 extends from the vicinity of the fulcrum shaft of the lever 11 toward the CCD lens holder 8 and is connected to the main substrate 18 (see FIG. 1).

  As shown in FIG. 1, the main substrate 18 is connected to a CCD 19 on a CCD plate 20 via a wiring (not shown), and the CCD 19 captures a subject image formed by the lens barrel 2.

  In this embodiment, the coil 12, the yoke 13, and the magnet 14 constitute a voice coil (driving means) as an actuator that drives the third lens group holder 7 in the optical axis direction of the lens L3. That is, the coil 12 attached to the operating point 11b of the lever 11 is disposed in a magnetic field formed by the yoke 13 penetrating the central air core portion 12a and the magnet 14 and the yoke 13 facing each other.

  Next, the operation of the lens driving device will be described.

  When a current is supplied to the winding of the coil 12 via the focus FPC 17, a Lorentz force acts in a direction orthogonal to the magnetic field and the current, a force acts on the operating point 11b of the lever 11, and the lever 11 around the fulcrum bearing 11a. Rotates.

  When the lever 11 rotates, the third group lens holder 7 in which the contact portion 7c comes into contact with the action point 11c is guided by the guide bar 9 and the steady bar 10 and is moved from the retracted position shown in FIG. 5 to the extended position shown in FIG. Go straight between.

  The position detector 16 detects the scale 15 to detect the position of the third group lens holder 7 in the optical axis direction, and controls the direction and amount of current flowing in the coil 12 based on the detected position. The third group lens holder 7 can be controlled to a predetermined position in the optical axis direction.

  As described above, in the present embodiment, the third group lens holder 7 is disposed on the inner peripheral side of the ring-shaped lever 11, and the axis of the fulcrum bearing 11a of the lever 11 is disposed at a position crossing the optical path of the third group lens L3. Has been.

  Thereby, the lens L3 and the lever 11 can be arranged so as to be folded on a plane perpendicular to the lens driving direction.

  As a result, the arrangement area of the members on a plane perpendicular to the lens driving direction can be reduced, and the lens driving device and thus the camera can be reduced in size.

  Next, a lens driving device according to the second embodiment of the present invention will be described with reference to FIGS.

  FIG. 7 is a cross-sectional view for explaining the internal structure of the camera equipped with the lens driving device according to the second embodiment of the present invention in the lens barrel storage state, and FIG. 8 shows the third group lens L103 in the retracted position. It is sectional drawing for demonstrating the internal structure in imaging | photography state.

  FIG. 9 is a cross-sectional view for explaining the internal structure in a photographing state in which the third group lens L103 is in the extended position, and FIG. 10 is an external perspective view of the camera.

  As shown in FIG. 10, a retractable lens barrel 102 is provided in front of the camera 101.

  As shown in FIG. 7, the lens barrel 102 includes a first group lens L101, a second group lens L102, and a third group lens L103, and adjusts the focus by moving the third group lens L103 in the optical axis direction. In FIGS. 11 and 12, the optical path of the third group lens L103 is indicated by a one-dot chain line.

  The first group lens L101 is held by a first group lens holder 103 having a first group cam pin 103a, and the second group lens L102 is held by a second group lens holder 104 having a second group cam pin 104a and a shutter unit 104b.

  A cam cylinder 105 and a fixed cylinder 106 are arranged on the outer peripheral side of the first group lens holder 103 and the second group lens holder 104.

  The cam cylinder 105 rotates about the optical axis, a gear portion 105a (not shown) is provided on the outer peripheral portion, and a first group cam groove 105b and a second group cam groove 105c are provided on the inner peripheral portion.

  In the fixed cylinder 106, the cam cylinder 105 is rotatably fitted on the outer peripheral portion, and three through-hole-like straight advance grooves 106a extending in the optical axis direction are formed on the peripheral wall so as to be separated from each other in the circumferential direction. A first group cam pin 103a and a second group cam pin 104a are fitted in the rectilinear groove 106a so as to be movable in the optical axis direction.

  Next, the operation of the retractable barrel 102 will be described.

  When a driving gear (not shown) connected to the gear portion 105 a of the cam cylinder 105 rotates, the cam cylinder 105 rotates around the fixed cylinder 106.

  When the cam cylinder 105 rotates, the first group cam pin 103a that engages with the first group cam groove 105b on the inner peripheral side of the cam cylinder 105 is guided by the rectilinear groove 106a along the lift of the first group cam groove 105b, and the optical axis direction Move to.

  Similarly, when the cam cylinder 105 rotates, the second group cam pin 104a that engages with the second group cam groove 105c on the inner peripheral side of the cam cylinder 105 is guided by the rectilinear groove 106a along the lift of the second group cam groove 105c. Move in the direction of the optical axis.

  Thus, the first group lens holder 103 and the second group lens holder 104 move in the optical axis direction, so that the first group lens L101 and the second group lens L102 are moved from the storage state shown in FIG. Move to the shooting state shown.

  Next, a lens driving device that moves the third lens group L103 forward and backward in the optical axis direction will be described with reference to FIGS.

  FIG. 11 is a perspective view showing the lens driving device with the third group lens L103 in the retracted position, and FIG. 12 is a perspective view showing the lens driving device with the third group lens L103 in the extended position.

  As shown in FIG. 11, the lens driving device includes a third group lens holder 107 for holding the third group lens L103, a CCD lens holder 108 having a fulcrum shaft 108a, and a ring-shaped lever 111 arranged so as to surround the optical axis. Prepare.

  The third group lens holder 107 is provided with a sleeve 107a, a steadying portion 107b, a contact portion 107c, and a position detection portion 116.

  The CCD lens holder 108 holds a guide bar 109 and a steady bar 110. The CCD lens holder 108 is provided with a yoke 113, a magnet 114, and a scale 115.

  The lever 111 has a pair of fulcrum bearings 111a at positions facing each other in the radial direction on the ring circumference. Further, the lever 111 has an operating point 111b disposed on the ring circumference at an intermediate position between the pair of fulcrum bearings 111a, and an action point 111c disposed on the ring circumference opposed to the operating point 111b in the radial direction.

  The fulcrum bearing 111a is fitted to the fulcrum shaft 108a of the CCD lens holder 108, and supports the lever 111 so as to be rotatable around an axis line that is orthogonal to the optical axis of the third lens group 103 and crosses the optical path. .

  The contact portion 107c of the third group lens holder 107 is urged so as to contact the action point 111c by a presser spring 111d formed of an elastic member or the like.

  A coil 112 is wound around the operating point 111b via an air core portion 112a. The coil 112 and the operating point 111b function as a counter balance weight for the third group lens holder 107.

  Here, in this embodiment, the fulcrum bearing 111a of the lever 111 is located closer to the operating point 111b than the intermediate position between the operating point 111c and the operating point 111b.

  Further, in the present embodiment, the lever 111 is formed by bending the operating point 111b and the action point 111c in the same direction as the lens moving direction with the fulcrum bearing 111a as a substantial apex.

  A focus FPC (flexible printed circuit board) 117 is attached to the side peripheral surface of the lever 111, one end of the focus FPC 117 is connected to the coil 112, and the other end is connected to the position detection unit 116.

  The focus FPC 117 extends from the vicinity of the fulcrum shaft of the lever 111 toward the CCD lens holder 108 and is connected to the main substrate 118 (see FIG. 7).

  As shown in FIG. 7, the main substrate 118 is connected to a CCD 119 on the CCD plate 120 via a wiring (not shown), and the CCD 119 captures a subject image formed by the lens barrel 102.

  Here, in the present embodiment, the coil 112, the yoke 113, and the magnet 114 constitute a voice coil (driving means) as an actuator that drives the third group lens holder 107 in the optical axis direction of the lens L103. That is, the coil 112 attached to the operating point 111b of the lever 111 is disposed in a magnetic field formed by the yoke 113 penetrating the central air core portion 112a and the magnet 114 and the yoke 113 facing each other.

  Next, the operation of the lens driving device will be described.

  When a current is supplied to the winding of the coil 112 via the focus FPC 117, a Lorentz force acts in a direction orthogonal to the magnetic field and the current, and a force acts on the operating point 111b of the lever 111, and the lever 111 is centered on the fulcrum bearing 111a. Rotates.

  When the lever 111 rotates, the third group lens holder 107 whose contact portion 107c comes into contact with the action point 111c is guided by the guide bar 109 and the steady bar 110, and is moved from the retracted position shown in FIG. 11 to the extended position shown in FIG. Go straight between.

  By detecting the scale 115 by the position detector 116, the position of the third group lens holder 107 in the optical axis direction is detected. The third group lens holder 107 can be controlled to a predetermined position in the optical axis direction by controlling the direction and amount of current flowing in the coil 112 based on the detection position.

  As described above, in the present embodiment, the third lens group holder 107 is disposed on the inner peripheral side of the ring-shaped lever 111, and the axis of the fulcrum bearing 111a of the lever 111 is disposed at a position crossing the optical path of the third lens group L103. Has been.

  Thereby, the lens L103 and the lever 111 can be arranged so as to be folded on a plane perpendicular to the lens driving direction.

  As a result, the arrangement area of the members on a plane perpendicular to the lens driving direction can be reduced, and the lens driving device and thus the camera can be reduced in size.

  In the present embodiment, the fulcrum bearing 111a of the lever 111 is located closer to the operating point 111b than the intermediate position between the operating point 111c and the operating point 111b.

  Thereby, the shake amount of the operating point 111b on the opposite side of the fulcrum of the lever 111 with respect to the length of the lens moving distance is reduced.

  As a result, there is no need to secure a retreat space so as not to interfere with the lever 111 on the operating point 111b side, and the actuator can be downsized.

  Further, in the present embodiment, the fulcrum bearing 111a of the lever 111 is formed as a substantially apex, and the operating point 111b and the action point 111c of the lever 111 are formed to bend in the same direction as the lens moving direction.

  As a result, the amount of movement of the operating point 111b of the lever 111 from the fulcrum bearing 111a to the side opposite to the lens moving direction is reduced.

  As a result, there is no need to secure a retracting space so that the lever 111 on the operating point 111b side and the CCD lens holder 108 do not interfere with each other, and the lens barrel can be further downsized in the lens moving direction.

  In addition, this invention is not limited to what was illustrated to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.

It is sectional drawing for demonstrating the internal structure in the lens-barrel accommodation state of the camera carrying the lens drive device which is the 1st Embodiment of this invention. It is sectional drawing for demonstrating the internal structure in the imaging | photography state in which the 3rd group lens L3 exists in a retracted position. It is sectional drawing for demonstrating the internal structure in the imaging | photography state in which the 3rd group lens L3 exists in an extension position. It is an external appearance perspective view of a camera. It is a perspective view which shows a lens drive device in the state which has the 3rd group lens L3 in a retracted position. It is a perspective view which shows a lens drive device in the state in which the 3rd group lens L3 exists in an extended position. It is sectional drawing for demonstrating the internal structure in the lens-barrel accommodation state of the camera which mounts the lens drive device which is the 2nd Embodiment of this invention. It is sectional drawing for demonstrating the internal structure in the imaging | photography state in which the 3rd group lens L103 exists in a retracted position. It is sectional drawing for demonstrating the internal structure in the imaging | photography state in which the 3rd group lens L103 exists in an extended position. It is an external appearance perspective view of a camera. It is a perspective view which shows a lens drive device in the state which has the 3rd group lens L103 in a retracted position. It is a perspective view which shows a lens drive device in the state which has the 3rd group lens L103 in a delivery position.

Explanation of symbols

L1 1st group lens L2 2nd group lens L3 3rd group lens 1 Camera 2 Lens barrel 7 3rd group lens holder 8 CCD lens holder 11 Lever 11a Support point bearing 11b Operating point 11c Action point 12 Coil 13 Yoke 14 Magnet

Claims (6)

A lens holder for holding the lens;
Driving means for driving the lens holder in the optical axis direction of the lens;
A weight that functions as a counter balance of the lens holder;
The lens holder has an operating point where the lens holder abuts and an operating point where the weight is attached, and the lens holder and the weight are connected to each other and arranged to be rotatable in a direction perpendicular to the optical axis of the lens. A lever, and
The lens driving device according to claim 1, wherein a rotation axis of the lever is disposed at a position crossing an optical path of the lens.   The lens driving device according to claim 1, wherein the lever has a ring shape, and the lens is disposed on an inner peripheral side of the ring shape.   The lever has a pair of rotation fulcrums arranged at positions opposed to each other in the radial direction on a ring-shaped circumference, and the action point is arranged at an intermediate position in the circumferential direction of the pair of rotation fulcrums, The lens driving device according to claim 2, wherein the operating point is arranged at a position facing the action point in a radial direction.   The lens driving device according to claim 3, wherein the pivot fulcrum of the lever is disposed closer to the operation point than an intermediate position between the action point and the operation point.   5. The lens according to claim 4, wherein the lever is formed by bending the operation point and the action point in the same direction as a movement direction of the lens with the rotation fulcrum as a vertex. Drive device.   An optical apparatus comprising the lens driving device according to any one of claims 1 to 5.

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