Objective lens drive apparatus, optical pickup device, and optical disk drive

Abstract

An objective lens drive apparatus includes a stationary member, a movable portion having an objective lens, an objective-lens holding member, and driving coils, and a plurality of rod-like elastic support members each having an axial direction parallel to a third direction perpendicular to a first direction and a second direction, the support members elastically supporting the movable portion so that the movable portion is movable to the stationary member in the first direction and the second direction. The movable portion is supported by the support members on both sides of the movable portion in the third direction, the support members are arranged on different planes perpendicular to the first direction, and the movable portion is arranged to be movable in the third direction with the support members, so that the objective lens is rotatable around an axis of the second direction.

1 - 13 . (canceled)  
   
   
       14 . An objective lens drive apparatus comprising: 
 a stationary member;    a movable portion having an objective lens, an objective-lens holding member holding the objective lens, and driving coils; and    a plurality of rod-like elastic support members provided between the stationary member and the movable portion, each support member having an axial direction that is parallel to a third direction perpendicular to both a first direction and a second direction, the support members elastically supporting the movable portion to be movable to the stationary member,    wherein the movable portion is supported by the support members on both sides of the movable portion, and the support members are arranged on a single plane perpendicular to the first direction and in the third direction symmetrically with respect to an optical axis of the objective lens.    
   
   
       15 . The objective lens drive apparatus according to  claim 14  wherein the driving coils comprise a coil generating a force in the first direction, a coil generating a force in the second direction, a coil generating a force in a tangential tilt direction, and a coil generating a force in a radial tilt direction, and wherein the plurality of rod-like elastic support members comprise eight rod-like elastic support members of a conductive substance, and electric current is supplied to the respective coils through said rod-like elastic support members.  
   
   
       16 . The objective lens drive apparatus according to  claim 14  wherein the single plane on which the support members are arranged is located near a principal point of the objective lens.  
   
   
       17 . The objective lens drive apparatus according to  claim 14  wherein a damping material is provided near portions of the movable portion to which the support members are attached.  
   
   
       18 . The objective lens drive apparatuses according to  claim 14  wherein the plurality of rod-like elastic support members are formed by dividing a sheet-like member which is integrally formed with the objective-lens holding member and the stationary member, into plural pieces.  
   
   
       19 . The objective lens drive apparatus according to  claim 18  wherein the plurality of rod-like elastic support members which are formed by dividing the sheet-like member are partially bent to reduce rigidity in the third direction.  
   
   
       20 . The objective lens drive apparatus according to  claim 14  wherein the plurality of rod-like elastic support members are arranged coaxially with respect to the third direction.  
   
   
       21 . The objective lens drive apparatus according to  claim 14  wherein ends of the support members attached to the stationary member are fixed to elastic boards that are provided on the stationary member to be slightly movable in the third direction.  
   
   
       22 . The objective lens drive apparatus according to  claim 14  wherein ends of the support members attached to the movable portion are soldered to lands of a printed circuit board, arranged at right angles to the first direction, on both sides of the movable portion in a radial direction thereof, and an effective length of each support member is regulated by end surfaces of the printed circuit board in the third direction.  
   
   
       23 . The objective lens drive apparatus according to  claim 22  wherein the printed circuit board is arranged on an opposite side of the objective lens with respect to a center of gravity of the movable portion.  
   
   
       24 . An objective lens drive apparatus comprising: 
 a stationary member;    a movable portion having an objective lens, an objective-lens holding member holding the objective lens, and driving coils; and    a plurality of rod-like elastic support members provided between the stationary member and the movable portion, each support member having an axial direction that is parallel to a third direction perpendicular to both a first direction and a second direction, the support members being arranged in the first direction apart from each other and elastically supporting the movable portion to be movable to the stationary member at least in a tangential tilt direction,    wherein the movable portion is supported by the support members on both sides of the movable portion, and the support members are arranged in the third direction symmetrically with respect to an optical axis of the objective lens,    the end on the side of the stationary member which supported the movable portion by the support members from both sides in the third direction, and is estranged in the first direction in the support member, it is fixed to the part from which the radius of gyration on the elastic board which the width of face of the focusing direction is formed narrowly partially, respectively, and rotates the shaft of the tracking direction as a center differs, the objective lens drive apparatus is configured so that the elastic board is rotatable corresponding to tangential tilt operation of the movable portion.    
   
   
       25 . An objective lens drive apparatus comprising: 
 a stationary member;    a movable portion having an objective lens, an objective-lens holding member holding the objective lens, and driving coils; and    a plurality of rod-like elastic support members provided between the stationary member and the movable portion, each support member having an axial direction that is parallel to a third direction perpendicular to both a first direction and a second direction, the support members being arranged in the first direction apart from each other and elastically supporting the movable portion to be movable to the stationary member at least in a tangential tilt direction,    wherein the movable portion is supported by the support members on both sides of the movable portion, and the support members are arranged in the third direction symmetrically with respect to an optical axis of the objective lens,    the elastic board being displaced to the third direction, and the support members being fixed smaller than a distance of the ends on the side of the elastic board a distance of the support member ends on the side of the movable portion in the focusing direction.    
   
   
       26 . The objective lens drive apparatus according to  claim 24  wherein the objective lens drive apparatus is configured so that the distance in the focusing direction of the movable portion side ends of the support members is smaller than the distance in the focusing direction of the ends on the side of the elastic board.  
   
   
       27 . The objective lens drive apparatus according to  claim 24  wherein by arranging the twist shaft of the elastic board on the perpendicular flat surface almost as opposed to the optical axis of the passage and the objective lens for the principal point of the objective lens.  
   
   
       28 . The objective lens drive apparatus according to  claim 26  wherein the support members near an optical disk installation side are arranged to allot the axis of the member perpendicularly to the optical axis of the objective lens, and the elastic support of the side far from the optical disk installation side having made the axis of the member incline to the optical disk.  
   
   
       29 . The objective lens drive apparatus according to  claim 28  wherein the objective lens drive apparatus is configured to meet the conditions Ls 1 /Ls 2 =Lw 1 /Lw 2  where Ls 1  is a distance in the first direction of the twist shaft of the elastic board and the support member ends on the stationary member on the optical disk installation side, Ls 2  is a distance in the first direction of the twist shaft of the elastic board and the support member ends on the stationary member on the opposite side of the optical disk installation side, Lw 1  is a distance in the first direction of the principal point of the objective lens and the support member ends on the movable portion on the optical disk installation side, and Lw 2  is a distance in the first direction of the principal point of the objective lens and the support member ends on the movable portion on the opposite side of the optical disk installation side.  
   
   
       30 . The objective lens drive apparatus according to  claim 25  wherein each of extended parts of the support members in the axial direction is provided to have an offset in the tracking direction so as to avoid interference.  
   
   
       31 . The objective lens drive apparatus according to  claim 24  wherein the plurality of rod-like elastic support members are constituted by flat springs which are parallel to a plane perpendicular to the first direction.  
   
   
       32 . The objective lens drive apparatus according to  claim 24  wherein the elastic board is constituted by a flexible circuit board.  
   
   
       33 . The objective lens drive apparatus according to  claim 24  wherein a viscoelasticity ingredient is provided between the elastic board and the stationary member.  
   
   
       34 . An optical pickup device comprising: 
 an objective lens drive apparatus;    a laser light source outputting a laser light beam to an optical disk;    a light-receiving optical unit receiving a reflected light beam from the optical disk; and    an objective-lens control unit outputting a control signal to the objective lens drive apparatus based on the reflected light beam received by the light-receiving optical unit,    the objective lens drive apparatus comprising:    a stationary member;    a movable portion having an objective lens, an objective-lens holding member holding the objective lens, and driving coils generating a first force in a first direction parallel to an optical axis of the objective lens and a second force in a second direction perpendicular to the optical axis of the objective lens; and    a plurality of rod-like elastic support members each having an axial direction parallel to a third direction perpendicular to both the first direction and the second direction, the support members elastically supporting the movable portion so that the movable portion is movable to the stationary member in the first direction and the second direction,    wherein the movable portion is supported by the support members on both sides of the movable portion in the third direction, the support members are arranged on different planes perpendicular to the first direction, and the movable portion is arranged to be movable in the third direction with the support members, so that the objective lens is rotatable around an axis of the second direction.    
   
   
       35 . An optical disk drive in which an optical pickup device, 
 a rotation drive unit controlling rotation of an optical disk, and a pickup drive unit moving the optical pickup device in a radial direction of the optical disk are provided,    the optical pickup device comprising:    an objective lens drive apparatus;    a laser light source outputting a laser light beam to the optical disk;    a light-receiving optical unit receiving a reflected light beam from the optical disk; and    an objective-lens control unit outputting a control signal to the objective lens drive apparatus based on the reflected light beam received by the light-receiving optical unit,    the objective lens drive apparatus comprising:    a stationary member;    a movable portion having an objective lens, an objective-lens holding member holding the objective lens, and driving coils generating a first force in a first direction parallel to an optical axis of the objective lens and a second force in a second direction perpendicular to the optical axis of the objective lens; and    a plurality of rod-like elastic support members each having an axial direction parallel to a third direction perpendicular to both the first direction and the second direction, the support members elastically supporting the movable portion so that the movable portion is movable to the stationary member in the first direction and the second direction,    wherein the movable portion is supported by the support members on both sides of the movable portion in the third direction, the support members are arranged on different planes perpendicular to the first direction, and the movable portion is arranged to be movable in the third direction with the support members, so that the objective lens is rotatable around an axis of the second direction.    
   
   
       36 . An objective lens drive apparatus comprising: 
 a stationary member having yokes;    a movable portion having an objective lens, an objective-lens holding member holding the objective lens, and driving coils;    a plurality of rod-like elastic support members each having an axial direction parallel to a tangential direction perpendicular to both a focusing direction and a tracking direction, the support members being arranged on different planes perpendicular to the focusing direction, the support members being fixed to the movable portion at one ends thereof, fixed to the stationary member at the other ends thereof and elastically supporting the movable portion so that the movable portion is movable to the stationary member in the focusing direction and the tracking direction; and    driving magnets attached to the yokes of the stationary member and arranged in the vicinity of the driving coils to form magnetic circuits with the driving coils,    wherein the other ends of the support members of the different planes fixed to the stationary member are arranged at different locations that are apart from each other in the axial directions thereof, thereby correcting a tangential tilt of the objective lens.    
   
   
       37 . An objective lens drive apparatus comprising: 
 a stationary member fixed to a housing of an optical pickup device;    a movable portion having an objective lens, an objective-lens holding member holding the objective lens, and driving coils;    a plurality of rod-like elastic support members each having an axial direction parallel to a third direction perpendicular to both a first direction and a second direction, the support members having one ends connected to the stationary member and other ends connected to the objective-lens holding member, the support member elastically supporting the movable portion so that the movable portion is movable to the stationary member in the first direction and the second direction; and    a tilt driving unit simultaneously generating both a rotating force to rotate the movable portion around a rotation axis in the first direction perpendicular to an optical axis of the objective lens, and a movement force to move the movable portion in the second direction parallel to the optical axis of the objective lens, based on at least one of a positional relation between a center of rotation of the movable portion and a principal point of the objective lens, a moment of inertia of the movable portion around the rotation axis, and characteristics of the support members, the movement force serving to cancel a part of movement of the principal point of the objective lens caused by the rotation of the movable portion.    
   
   
       38 . An optical pickup device comprising: 
 an objective lens drive apparatus;    a laser light source outputting a laser light beam to an optical disk;    a light receiving optical unit receiving a reflected light beam from the optical disk; and    an objective-lens control unit outputting a control signal to the objective lens drive apparatus based on the reflected light beam received by the light receiving optical unit,    the objective lens drive apparatus comprising:    a stationary member having yokes;    a movable portion having an objective lens, an objective-lens holding member holding the objective lens, and driving coils;    a plurality of rod-like elastic support members each having an axial direction parallel to a tangential direction perpendicular to both a focusing direction and a tracking direction, the support members being arranged on different planes perpendicular to the focusing direction, the support members being fixed to the movable portion at one ends thereof, fixed to the stationary member at the other ends thereof and elastically supporting the movable portion so that the movable portion is movable to the stationary member in the focusing direction and the tracking direction; and    driving magnets attached to the yokes of the stationary member and arranged in the vicinity of the driving coils to form magnetic circuits with the driving coils,    wherein the other ends of the support members of the different planes fixed to the stationary member are arranged at different locations that are apart from each other in the axial directions thereof, thereby correcting a tangential tilt of the objective lens.    
   
   
       39 . An optical pickup device comprising: 
 an objective lens drive apparatus;    a laser light source outputting a laser light beam to an optical disk;    a light receiving optical unit receiving a reflected light beam from the optical disk; and    an objective-lens control unit outputting a control signal to the objective lens drive apparatus based on the reflected light beam received by the light receiving optical unit,    the objective lens drive apparatus comprising:    a stationary member fixed to a housing of the optical pickup device;    a movable portion having an objective lens, an objective-lens holding member holding the objective lens, and driving coils;    a plurality of rod-like elastic support members each having an axial direction parallel to a third direction perpendicular to both a first direction and a second direction, the support members having one ends connected to the stationary member and other ends connected to the objective-lens holding member, the support member elastically supporting the movable portion so that the movable portion is movable to the stationary member in the first direction and the second direction; and    a tilt driving unit simultaneously generating both a rotating force to rotate the movable portion around a rotation axis in the first direction perpendicular to an optical axis of the objective lens, and a movement force to move the movable portion in the second direction parallel to the optical axis of the objective lens, based on at least one of a positional relation between a center of rotation of the movable portion and a principal point of the objective lens, a moment of inertia of the movable portion around the rotation axis, and characteristics of the support members, the movement force serving to cancel a part of movement of the principal point of the objective lens caused by the rotation of the movable portion.    
   
   
       40 . An optical disk drive in which an optical pickup device, a rotation drive unit controlling rotation of an optical disk, and a pickup drive unit moving the optical pickup device in a radial direction of the optical disk are provided, 
 the optical pickup device comprising:    an objective lens drive apparatus;    a laser light source outputting a laser light beam to the optical disk;    a light-receiving optical unit receiving a reflected light beam from the optical disk; and    an objective-lens control unit outputting a control signal to the objective lens drive apparatus based on the reflected light beam received by the light-receiving optical unit,    the objective lens drive apparatus comprising:    a stationary member having yokes;    a movable portion having an objective lens, an objective-lens holding member holding the objective lens, and driving coils;    a plurality of rod-like elastic support members each having an axial direction parallel to a tangential direction perpendicular to both a focusing direction and a tracking direction, the support members being arranged on different planes perpendicular to the focusing direction, the support members being fixed to the movable portion at one ends thereof, fixed to the stationary member at the other ends thereof and elastically supporting the movable portion so that the movable portion is movable to the stationary member in the focusing direction and the tracking direction; and    driving magnets attached to the yokes of the stationary member and arranged in the vicinity of the driving coils to form magnetic circuits with the driving coils,    wherein the other ends of the support members of the different planes fixed to the stationary member are arranged at different locations that are apart from each other in the axial directions thereof, thereby correcting a tangential tilt of the objective lens.    
   
   
       41 . An optical disk drive in which an optical pickup device, a rotation drive unit controlling rotation of an optical disk, and a pickup drive unit moving the optical pickup device in a radial direction of the optical disk are provided, 
 the optical pickup device comprising:    an objective lens drive apparatus;    a laser light source outputting a laser light beam to the optical disk;    a light-receiving optical unit receiving a reflected light beam from the optical disk; and    an objective-lens control unit outputting a control signal to the objective lens drive apparatus based on the reflected light beam received by the light-receiving optical unit,    the objective lens drive apparatus comprising:    a stationary member fixed to a housing of the optical pickup device;    a movable portion having an objective lens, an objective-lens holding member holding the objective lens, and driving coils;    a plurality of rod-like elastic support members each having an axial direction parallel to a third direction perpendicular to both a first direction and a second direction, the support members having one ends connected to the stationary member and other ends connected to the objective-lens holding member, the support member elastically supporting the movable portion so that the movable portion is movable to the stationary member in the first direction and the second direction; and    a tilt driving unit simultaneously generating both a rotating force to rotate the movable portion around a rotation axis in the first direction perpendicular to an optical axis of the objective lens, and a movement force to move the movable portion in the second direction parallel to the optical axis of the objective lens, based on at least one of a positional relation between a center of rotation of the movable portion and a principal point of the objective lens, a moment of inertia of the movable portion around the rotation axis, and characteristics of the support members, the movement force serving to cancel a part of movement of the principal point of the objective lens caused by the rotation of the movable portion.