|20030117935||Rotary drive device||June, 2003||Utsumi et al.|
|20060028966||Braille atomic storage at room temperature and open air||February, 2006||Szu|
|20070097835||Optical pick-up having a rotary arm actuator||May, 2007||Ophey et al.|
|20080291809||DISC ROTATION CONTROL METHOD AND VIDEO CAMERA||November, 2008||Ishitobi|
|20040131209||Operation panel structure and control method and control apparatus for mixing system||July, 2004||Okabayashi|
|20090109808||OPTICAL HEAD DEVICE AND INFORMATION||April, 2009||Kaji et al.|
|20080205249||COMPATIBLE OPTICAL PICKUP AND OPTICAL INFORMATION STORAGE MEDIUM SYSTEM EMPLOYING- THE SAME||August, 2008||Bae et al.|
|20080117754||Calibration method for Optimum Power Control (OPC) of laser write strategy in an optical storage device||May, 2008||YU|
|20080094950||OPTICAL PICKUP APPARATUS, METHOD OF PRODUCING THE SAME, AND OPTICAL INFORMATION RECORDER-REPRODUCER INCLUDING THE SAME||April, 2008||Nakamura et al.|
|20100067344||INFORMATION STORAGE DEVICE HAVING A DISK DRIVE AND A BRIDGE CONTROLLER PCB WITHIN A MONOLITHIC CONDUCTIVE NEST||March, 2010||Szeremeta et al.|
|20080310288||Universal Numerical Disc of Optically Readable Type||December, 2008||Fetouhi|
 1. Field of the Invention
 The present invention relates to a disk recording apparatus and particularly to a disk apparatus for recording or reproducing information onto or from a recording disk such as a compact disk (CD) and a digital versatile disk (DVD), and more particularly to a head driving apparatus for moving a pickup head with respect to a recording disk.
 2. Description of the Related Art
 In resent years, development of an optical disk apparatus as a disk recording apparatus has proceeded. Particularly, a writing function has been additionally provided to a recording apparatus for an optical medium such as a CD-ROM, and, also for a driving apparatus for moving an optical pickup unit (OPU) as a pickup head for recording an information signal onto an optical disk in a radial direction of an optical disk, a function for feeding the optical pickup unit smoothly and accurately is demanded. At the same time, in order to achieve high-quality writing of writing data, an apparatus for adjusting the posture of the optical pickup unit so that an optical axis of laser light emitted from the optical pickup unit and a recording face of an optical disk may extend perpendicularly to each other is demanded.
 As such an optical disk driving apparatus as described above, an apparatus is available which moves the optical pickup unit using a lead screw.
 Referring to FIGS.
 In the optical head driving apparatus in which such a tooth unit as described above is used, if the lead screw
 In the optical head driving apparatus, in order that the optical axis of the laser light emitted from the optical pickup unit
 However, in the optical head driving apparatus having such a configuration as described above, if the skew of the main and sub guide rails
 It is to be noted that Japanese Patent Laid-Open No. 2001-160272 discloses an apparatus wherein a rack (toothed member) provided on an optical pickup unit is resiliently pressed to a lead screw to achieve smooth movement of the optical pickup unit. However, the apparatus controls the inclination of the rack to secure a meshing engagement state between the rack and the lead screw and presupposes that a parallel state between the guide rails and the lead screw is secured. Therefore, it is difficult to solve such a trouble when the parallelism between the guide rails and the lead screw in the Z-axis direction is deteriorated as described above using the apparatus.
 It is an object of the present invention to provide a head driving apparatus which can correctly adjust the posture of an optical pickup unit and can smoothly move the optical pickup unit.
 In order to attain the object of described above, according to an aspect of the present invention, there is provided a head driving apparatus for a disk apparatus comprising a pickup head movable in an X-axis direction on a plane of X-Y coordinates along a guide rail for performing recording or reproduction of information onto or from a recording disk, a lead screw rotationally driven to move the pickup head in the X-axis direction, and a toothed member held in meshing engagement with the lead screw for moving the pickup head in the X-axis direction upon rotation of the lead screw, the toothed member being supported for pivotal motion on the pickup head within a range of a small angle on a plane of Z-X coordinates perpendicular to the X-Y coordinate plane on which the pickup head is moved.
 Preferably, the toothed member is supported for pivotal motion on the pickup head within a range of a small angle also in the X-Y coordinate plane on which the pickup head is moved.
 The toothed member may be disposed for pivotal motion with respect to the pickup head by means of a pivot extending in a Y-axis direction.
 The head driving apparatus may further comprise a tooth base provided on the pickup head, and the toothed member may be supported for pivotal motion on the tooth base by the pivot extending in the Y-axis direction.
 The head driving apparatus may further comprise a tooth spring interposed between the toothed member and the tooth base for resiliently pressing the toothed member to the lead screw and braking the pivotal motion of the toothed member. The tooth spring may be a coil spring arranged around the pivot.
 Preferably, the pivot is formed from a boss provided on a rear face of the toothed member and inserted in a bush provided on a front face of the tooth base. Further preferably, the bush and the boss form a spherical bearing structure.
 The head driving apparatus may be configured such that a pair of claw portions are provided on a rear face of the toothed member and inserted in a pair of slits, which are provided on a front face of the tooth base with clearances formed therebetween such that a pivotal motion of the toothed member within a small angle with respect to the tooth base is allowed by the clearances, and removal of the toothed member from the tooth base is prevented by the engagement between the claw portions and the tooth base.
 The pickup head may be an optical pickup unit.
 In the head driving apparatus for a disk apparatus, the toothed member can pivotally move within a range of a small angle on the Z-X coordinate plane rectangular to the X-Y coordinate plane on which the pickup head is moved. Therefore, even if the parallelism in the Z-axis direction between the guide rail and the lead screw is deteriorated, the toothed member is directed to a preferable angular position with respect to the lead screw so that the toothed member and the lead screw are brought into appropriate meshing engagement with each other. As a result, smooth movement of the pickup head is secured.
 Further, the toothed member can pivotally move within a range of a small angle also on the X-Y coordinate plane on which the pickup head moves. Therefore, even if the parallelism in the Y-axis direction is deteriorated, the toothed member is pivotally moved in a follow-up manner so that the toothed member and the lead screw are brought into appropriate meshing engagement with each other. As a result, smooth movement of the pickup head is secured.
 The above and other objects, features and advantages of the present invention will become apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings in which like parts or elements are denoted by like reference symbols.
 A head driving apparatus according to the present invention is applied to the optical disk apparatus described hereinabove with reference to
 A spindle motor
 An objective lens
 A lead screw
 The tooth unit
 Referring now to FIGS.
 The toothed member
 When the left and right claw portions
 Further, a tooth spring
 With the optical disk apparatus having the configuration described above, if the lead screw
 Incidentally, in the optical pickup unit
 However, when the parallelism between the lead screw
 Further, the tooth spring
 In particular, not such a mere circular boss as described above but a boss
 According to the modification, similarly as in the embodiment described above, the toothed member
 Further, since the spherical bearing structure is formed from the boss
 It is to be noted that the present invention is not limited to an optical head driving apparatus for an optical disk apparatus, but can be applied also to a recording disk apparatus which includes a function for adjusting the skew of guide rails in order to adjust the angle of a pickup head with respect to a recording disk. Also, for example, in a magneto-optical disk apparatus, since a function for adjusting the angle of a magneto-optical head with respect to a magneto-optical disk is demanded, the present invention can be applied also to the magneto-optical head driving apparatus.
 While a preferred embodiment of the present invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.