US4752117A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Objective lens driving device
Assignee: Hitachi Ltd
•
Filing: 1986-10-23
•
Granted: 1988-06-21
•
Expires: 2006-10-23
Abstract
Abstract Disclosed is a device for driving an objective lens of an optical disk apparatus in both the tracking direction and the focusing direction. The device comprises a rocker arm supported rotatably and axially slidably by a supporting shaft and carrying the objective lens on its front end, a pair of first coils disposed on both sides respectively of an end on rear end of the rocker arm remote from the front end carrying the objective lens for driving the objective lens in the tracking direction, and a second coil mounted to the lower surface of the rocker arm for driving the objective lens in the focusing direction. A pair of magnets for producing a magnetic field for driving the objective lens in the focusing direction and a magnetic field for driving the objective lens in the tracking direction are mounted to a pair of yokes erected on both sides of the supporting shaft respectively. Current is supplied to the first coils to produce moments of rotation rotating the rocker arm thereby driving the objective lens in the tracking direction, and current is supplied to the second coil to move the rocker arm in the axial direction of the supporting shaft thereby driving the objective lens in the focusing direction.
Inventors
- 👤 Atsushi Ichikawa
- 👤 Masayuki Abe
- 👤 Akio Yabe
- 👤 Hideo Onuki
- 👤 Shigefumi Hida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 06:29
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/09; G11B7/0925; G11B7/093
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
283 words
An objective lens driving device comprising: a supporting shaft erected on a base plate; a pair of yokes erected on said base plate on both sides of said supporting shaft in a relation spaced apart from said supporting shaft; a pair of magnets mounted to said yokes respectively; a rocker arm supported by said supporting shaft so as to be rotatable around the axis of said supporting shaft and movable in the axial direction of said supporting shaft; an objective lens mounted on said rocker arm at an end portion which is a front portion relative to said supporting shaft; coil means for driving said objective lens in the rotating direction of said rocker arm including only one pair of first coils, said first coils being disposed on both sides respectively of an end portion of said rocker arm which is a rear portion relative to said supporting shaft; a second coil mounted to the lower surface of said rocker arm with the center of the winding thereof registering substantially with the axis of said supporting shaft so as to drive said objective lens in the axial direction of said supporting shaft; means for supplying current to the pair of said first coils to generate electromagnetic forces in said first coils in directions opposite to each other for producting moments of rotation tending to rotate said rocker arm around the axis of said supporting shaft thereby driving said objective lens in the rotating direction of said rocker arm; and means for supplying current to said second coil to move said rocker arm in the axial direction of said supporting shaft thereby driving said objective lens in the axial direction of said supporting shaft.
Claim 2
Dependent Claim
283 words
An objective lens driving device comprising: a supporting shaft erected on a base plate; a pair of yokes erected on said base plate on both sides of said supporting shaft in a relation spaced apart from said supporting shaft; a pair of magnets mounted to said yokes respectively; a rocker arm supported by said supporting shaft so as to be rotatable around the axis of said supporting shaft and movable in the axial direction of said supporting shaft; an objective lens mounted on said rocker arm at an end portion which is a front portion relative to said supporting shaft; coil means for driving said objective lens in the rotating direction of said rocker arm including only one pair of first coils, said first coils being disposed on both sides respectively of an end portion of said rocker arm which is a rear portion relative to said supporting shaft; a second coil mounted to the lower surface of said rocker arm with the center of the winding thereof registering substantially with the axis of said supporting shaft so as to drive said objective lens in the axial direction of said supporting shaft; means for supplying current to the pair of said first coils to generate electromagnetic forces in said first coils in directions opposite to each other for producting moments of rotation tending to rotate said rocker arm around the axis of said supporting shaft thereby driving said objective lens in the rotating direction of said rocker arm; and means for supplying current to said second coil to move said rocker arm in the axial direction of said supporting shaft thereby driving said objective lens in the axial direction of said supporting shaft.
Claim 3
Dependent Claim
25 words
An objective lens driving device as claimed in claim 1, wherein the pair of said yokes are formed as integral parts of said base plate.
Claim 4
Dependent Claim
48 words
An objective lens driving device as claimed in claim 1, wherein the pair of said first coils are each bent at right angles in the middle thereof and are mounted at the bent portions to the side surfaces respectively of the rear end portion of said rocker arm.
Claim 5
Dependent Claim
40 words
An objective lens driving device as claimed in claim 1, wherein a coil holder is joined to the rear end portion of said rocker arm, and said first coils are mounted to the side surfaces respectively of said coil holder.
Claim 6
Dependent Claim
20 words
An objective lens driving device as claimed in claim 1, wherein said rocker arm is made of a non-magnetic material.
Claim 7
Dependent Claim
89 words
An objective lens driving device as claimed in claim 1, wherein each of the pair of said magnets mounted to the pair of said yokes respectively includes a first magnet producing a magnetic field having at least a component for driving said objective lens in the axial direction of said supporting shaft and a component for driving said objective lens in the rotating direction of said rocker arm, and a second magnetic spaced apart from said first magnet and disposed nearer to the associated one of said first coils.
Claim 8
Dependent Claim
299 words
An objective lens driving device comprising: a supporting shaft erected on a front end portion of a base plate; a pair of first yokes erected on said base plate on both sides of said supporting shaft in a relation spaced apart from said supporting shaft; a pair of second yokes erected on said base plate on both sides of said supporting shaft and outside of the pair of said first yokes in a relation spaced apart from said first yoke pair; a pair of magnets mounted to the pair of said second yokes respectively; a rocker arm supported by said supporting shaft so as to be rotatable around the axis of said supporting shaft and movable in the axial direction of said supporting shaft; an objective lens mounted on a front end portion of said rocker arm; a pair of first coils disposed opposite to said magnets on both sides of a rear end portion of said rocker arm respectively so as to drive said objective lens in the rotating direction of said rocker arm; a second coil mounted to the lower surface of said rocker arm with the center of the winding thereof registering substantially with the axis of said supporting shaft, said second coil being inserted in air gaps defined between said first yoke pair and said second yoke pair; means for supplying current to the pair of said first coils to produce moments of rotation tending to rotate said rocker arm around the axis of said supporting shaft thereby driving said objective lens in the rotating direction of said rocker arm; and means for supplying current to said second coil to move said rocker arm in the axial direction of said supporting shaft thereby driving said objective lens in the axial direction of said supporting shaft.
Claim 9
Dependent Claim
299 words
An objective lens driving device comprising: a supporting shaft erected on a front end portion of a base plate; a pair of first yokes erected on said base plate on both sides of said supporting shaft in a relation spaced apart from said supporting shaft; a pair of second yokes erected on said base plate on both sides of said supporting shaft and outside of the pair of said first yokes in a relation spaced apart from said first yoke pair; a pair of magnets mounted to the pair of said second yokes respectively; a rocker arm supported by said supporting shaft so as to be rotatable around the axis of said supporting shaft and movable in the axial direction of said supporting shaft; an objective lens mounted on a front end portion of said rocker arm; a pair of first coils disposed opposite to said magnets on both sides of a rear end portion of said rocker arm respectively so as to drive said objective lens in the rotating direction of said rocker arm; a second coil mounted to the lower surface of said rocker arm with the center of the winding thereof registering substantially with the axis of said supporting shaft, said second coil being inserted in air gaps defined between said first yoke pair and said second yoke pair; means for supplying current to the pair of said first coils to produce moments of rotation tending to rotate said rocker arm around the axis of said supporting shaft thereby driving said objective lens in the rotating direction of said rocker arm; and means for supplying current to said second coil to move said rocker arm in the axial direction of said supporting shaft thereby driving said objective lens in the axial direction of said supporting shaft.
Claim 10
Dependent Claim
26 words
An objective lens driving device as claimed in claim 7, wherein the pair of said second yokes are formed by bending portions of said base plate.
Claim 11
Dependent Claim
47 words
An objective lens driving device as claimed in claim 7, wherein the pair of said first coils are each bent at right angles in the middle thereof and are mounted at the bent portions to the side surface respectively of the rear end of said rocker arm.
Claim 12
Dependent Claim
40 words
An objective lens driving device as claimed in claim 7, wherein a coil holder is joined to the rear end portion of said rocker arm, and said first coils are mounted to the side surfaces respectively of said coil holder.
Claim 13
Dependent Claim
20 words
An objective lens driving device as claimed in claim 7, wherein said rocker arm is made of a non-magnetic material.
Claim 14
Dependent Claim
90 words
An objective lens driving device as claimed in claim 7, wherein each of the pair of said magnets mounted to the pair of said second yokes respectively includes a first magnet producing a magnetic field having at least a component for driving said objective lens in the axial direction of said supporting shaft and a component for driving said objective lens in the rotating direction of said rocker arm, and a second magnet spaced apart from said first magnet and disposed nearer to the associated one of said first coils.
Claim 15
Dependent Claim
33 words
An objective lens driving device as claimed in claim 1, wherein said pair of yokes and said pair of magnets mounted to said yokes are disposed on opposite sides of said rocker arm.
Claim 16
Dependent Claim
52 words
An objective lens driving device as claimed in claim 13, wherein said pair of yokes and said pair of magnets mounted thereon are arranged on opposite sides of said rocker arm proximate to the rear end portion of said rocker arm and spaced from the front end portion of said rocker arm.
Claim 17
Dependent Claim
34 words
An objective lens driving device as claimed in claim 1, wherein said coil means for driving said objective lens in the rotating direction of said rocker arm provides a counterweight for said objective lens.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-21 | 1991-12-21 | 1992-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-21 | 1995-12-21 | 1996-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-21 | 1999-12-21 | 2000-06-21 | $7700.00 | Window Closed / Lapsed |