US4956833A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Objective driving device for an optical disk apparatus
Assignee: Pentax Corp
•
Filing: 1989-12-26
•
Granted: 1990-09-11
•
Expires: 2009-12-26
Abstract
Abstract An optical disk apparatus comprises an optical pickup having an optical pickup body carrying a laser and a photodetector responsive to light emitted from the laser and reflected by the optical disk for producing tracking error signals mounted on the optical pickup body for reciprocal movement in a tracking direction responsive to operation of an actuator, and supports an objective for focusing the beam on the disk. A position sensor produces position signals in response to displacement of the movable portion in the tracking direction. Finally a servo tracking circuit outputs driving signals to the actuator on the basis of tracking error signals produced either in response to tracking error signals produced from outputs of the photodetector and position signals produced from output signals of the position sensor, in response only to the latter. The optical disk apparatus having the foregoing construction eliminates direct-current offset included in tracking error signals, stabilizes driving of the objective, and reduces access time.
Inventors
- 👤 Hiroshi Kokado
- 👤 Suguru Takishima
- 👤 Koichiro Nishikawa
- 👤 Junichi Takeda
- 👤 Masahiko Sasaki
- 👤 Isao Okuda
- 👤 Hiroshi Yamamoto
- 👤 Masami Ninomiya
- 👤 Akihiro Tanaka
- 👤 Hiroshi Motohashi
- 👤 Makoto Iwaki
- 👤 Wataru Kubo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:56
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B33/00; G11B33/02; G11B33/08; G11B7/08; G11B7/09; G11B7/0925; G11B7/093; G11B7/094
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
274 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track and for rotation about an axis perpendicular to the plane of the disk; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals; and (i) said light receiving means including at least two photosensitive receivers displaced from each other in the tracking direction, said light source being different from said laser, said movable portion including a planar plate having a surface parallel to the plane of said disk, said receivers being mounted on said plate, and said light source being mounted on said optical pickup body.
Claim 2
Dependent Claim
274 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track and for rotation about an axis perpendicular to the plane of the disk; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals; and (i) said light receiving means including at least two photosensitive receivers displaced from each other in the tracking direction, said light source being different from said laser, said movable portion including a planar plate having a surface parallel to the plane of said disk, said receivers being mounted on said plate, and said light source being mounted on said optical pickup body.
Claim 3
Dependent Claim
285 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track and for rotation about an axis perpendicular to the plane of the disk; (c) an optical system, including an objective mounted on said movable portions, for focusing laser light into a spot on said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals; and (i) said light receiving means including at least two photosensitive receivers displaced from each other in the tracking direction, said light source being different from said laser, said movable portion including a planar plate having a surface parallel to the plane of said disk, and also including a central boss rigidly connected to said plate, and said receivers are mounted on said boss, said light source being mounted on said optical pickup body.
Claim 4
Dependent Claim
285 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track and for rotation about an axis perpendicular to the plane of the disk; (c) an optical system, including an objective mounted on said movable portions, for focusing laser light into a spot on said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals; and (i) said light receiving means including at least two photosensitive receivers displaced from each other in the tracking direction, said light source being different from said laser, said movable portion including a planar plate having a surface parallel to the plane of said disk, and also including a central boss rigidly connected to said plate, and said receivers are mounted on said boss, said light source being mounted on said optical pickup body.
Claim 5
Dependent Claim
262 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track, said movable portion being provided with a mirror having a pair of inclined surfaces; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals; and (i) said light receiving means including at least two photosensitive receivers displaced from each other in the tracking direction, said light source being different from said laser, said receivers and said light sources being mounted on said body, and light from said source being reflected from said movable portion.
Claim 6
Dependent Claim
262 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track, said movable portion being provided with a mirror having a pair of inclined surfaces; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals; and (i) said light receiving means including at least two photosensitive receivers displaced from each other in the tracking direction, said light source being different from said laser, said receivers and said light sources being mounted on said body, and light from said source being reflected from said movable portion.
Claim 7
Dependent Claim
265 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track, said movable portion being provided with a plane mirror whose reflectivity differs in the tracking direction; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals; and (i) said light receiving means including at least two photosensitive receivers displaced from each other in the tracking direction, and said light source being different from said laser, said receivers and said light source being mounted on said body, and light from said source being reflected from said movable portion.
Claim 8
Dependent Claim
265 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track, said movable portion being provided with a plane mirror whose reflectivity differs in the tracking direction; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals; and (i) said light receiving means including at least two photosensitive receivers displaced from each other in the tracking direction, and said light source being different from said laser, said receivers and said light source being mounted on said body, and light from said source being reflected from said movable portion.
Claim 9
Dependent Claim
222 words
An optical pickup for a planar optical dish having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals; and (i) a mask interposed between said receiving means and said light source, said mask having a transmissivity that varies in the tracking direction.
Claim 10
Dependent Claim
222 words
An optical pickup for a planar optical dish having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals; and (i) a mask interposed between said receiving means and said light source, said mask having a transmissivity that varies in the tracking direction.
Claim 11
Dependent Claim
19 words
An optical pickup according to claim 5 wherein said mask is in the form of a triangularly shaped aperture.
Claim 12
Dependent Claim
25 words
An optical pickup according to claim 5 wherein said mask is in the form of a plurality of separate apertures whose projected area is triangular.
Claim 13
Dependent Claim
29 words
An optical pickup according to claim 5 wherein said mask is in the form of a plurality of separate apertures of different widths which change in the tracking direction.
Claim 14
Dependent Claim
25 words
An optical pickup according to claim 5 wherein said mask is in the form of a plate whose optical density varies in the tracking direction.
Claim 15
Dependent Claim
271 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals; (i) said light receiving means including at least two photosensitive receivers displaced from each other in the tracking direction, said light source being different from said laser; and (j) a mask interposed between said receiving means and said source for limiting illumination from said source to an area no larger than the area of the receivers when the spot from the laser light is centered on at least one track on the disk.
Claim 16
Dependent Claim
271 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals; (i) said light receiving means including at least two photosensitive receivers displaced from each other in the tracking direction, said light source being different from said laser; and (j) a mask interposed between said receiving means and said source for limiting illumination from said source to an area no larger than the area of the receivers when the spot from the laser light is centered on at least one track on the disk.
Claim 17
Dependent Claim
30 words
An optical pickup according to claim 10 wherein each receiver produces receiver signals, and said position sensor includes a circuit for subtracting said receivers signals to produce said position signal.
Claim 18
Dependent Claim
224 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; and (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals, said light receiving means including at least two photosensitive receivers displaced from each other in the tracking direction, and said light source being the laser.
Claim 19
Dependent Claim
224 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; and (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals, said light receiving means including at least two photosensitive receivers displaced from each other in the tracking direction, and said light source being the laser.
Claim 20
Dependent Claim
28 words
An optical pickup according to claim 12 wherein said receivers are mounted on said body, and laser light incident thereon passes through an aperture in said movable portion.
Claim 21
Dependent Claim
16 words
An optical pickup according to claim 12 wherein said receivers are mounted on said movable portion.
Claim 22
Dependent Claim
37 words
An optical pickup according to claim 14 wherein said receivers are mounted in a plane perpendicular to the axis of said objective and are provided with notches that direct the passage of laser light through said objective.
Claim 23
Dependent Claim
24 words
An optical pickup according to claim 12 wherein said receivers are mounted on said optical pickup body symmetrically about the axis of said objective.
Claim 24
Dependent Claim
80 words
An optical pickup according to claim 12 wherein said servo circuit includes: (a) a first subtractor for taking the difference between said position signals to produce the tracking error signal; (b) a second subtractor for taking the difference between a feedback signal and said tracking error signal to produce a difference signal; (c) a processor for processing said difference signal to form said driving signal; and (d) a feedback circuit responsive to said driving signal for producing said feedback signal.
Claim 25
Dependent Claim
26 words
A tracking servo circuit according to claim 17 wherein said feedback circuit includes a low-pass filter for removing any DC offset in said tracking error signals.
Claim 26
Dependent Claim
350 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals; (i) said light receiving means including at least two photosensitive receivers displaced from each other in the tracking direction, and said light source being different from said laser; (j) said servo tracking circuit including a first subtracter for producing said position signals by taking the difference between signals produced by said receivers; and (k) said photodetector comprising at least two separate detectors, and said servo tracking circuit including a second subtractor for producing tracking error signals by taking the difference between signals produced by said detectors, means for scaling said position signals to produce scaled position signals, a third subtracter for taking the difference between said scaled position signals and said tracking error signals for producing a difference signal, means to process said difference signal to produce a processed difference signal, and a fourth subtracter for taking the difference between said processed difference signal and position signals for producing said driving signal.
Claim 27
Dependent Claim
350 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction essentially perpendicular to a track; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing tracking error signals; (e) a position sensor for producing position signals that establish the position of said movable portion relative to said body; (f) a servo tracking circuit responsive to said position signals and said tracking error signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including a light source, and light receiving means for receiving light from said source, said position sensor being constructed and arranged so that said light receiving means produces said position signals; (i) said light receiving means including at least two photosensitive receivers displaced from each other in the tracking direction, and said light source being different from said laser; (j) said servo tracking circuit including a first subtracter for producing said position signals by taking the difference between signals produced by said receivers; and (k) said photodetector comprising at least two separate detectors, and said servo tracking circuit including a second subtractor for producing tracking error signals by taking the difference between signals produced by said detectors, means for scaling said position signals to produce scaled position signals, a third subtracter for taking the difference between said scaled position signals and said tracking error signals for producing a difference signal, means to process said difference signal to produce a processed difference signal, and a fourth subtracter for taking the difference between said processed difference signal and position signals for producing said driving signal.
Claim 28
Dependent Claim
22 words
An optical pickup according to claim 19 including a selectively operable switch for selectively disconnecting said difference signal from said fourth subtractor.
Claim 29
Dependent Claim
239 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing reading signals; (e) a position sensor for producing position signals that establish the position of said spot relative to a track; (f) a servo tracking circuit responsive to said position signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including means for establishing a parameter functionally related to the position of the movable portion on the optical pickup body, said position sensor being responsive to said parameter for generating said position signals; and (i) said means for establishing a parameter including resilient suspension means linking said movable portion to said optical pickup body, said parameter being the strain in said suspension means, and a strain gauge associated with said suspension means for measuring the strain in said suspension means and producing position signals.
Claim 30
Dependent Claim
239 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing reading signals; (e) a position sensor for producing position signals that establish the position of said spot relative to a track; (f) a servo tracking circuit responsive to said position signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; (h) said position sensor including means for establishing a parameter functionally related to the position of the movable portion on the optical pickup body, said position sensor being responsive to said parameter for generating said position signals; and (i) said means for establishing a parameter including resilient suspension means linking said movable portion to said optical pickup body, said parameter being the strain in said suspension means, and a strain gauge associated with said suspension means for measuring the strain in said suspension means and producing position signals.
Claim 31
Dependent Claim
242 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing reading signals; (e) a position sensor for producing position signals that establish the position of said spot relative to a track; (f) a servo tracking circuit responsive to said position signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; and (h) said position sensor including means for establishing a parameter functionally related to the position of the movable portion on the optical pickup body, and means responsive to said parameter for generating said position signals, said means for establishing a parameter includes opposed Hall effect elements mounted on said movable portion facing permanent magnets mounted on said optical pickup body, said parameter being the Hall voltage generated by said Hall effect elements, and a Hall effect generator responsive to said Hall elements for producing Hall voltages constituting said position signals.
Claim 32
Dependent Claim
242 words
An optical pickup for a planar optical disk having a plurality of tracks, said optical pickup comprising: (a) an optical pickup body provided with a laser for producing laser light; (b) a movable portion mounted on said optical pickup body for movement relative thereto in a tracking direction; (c) an optical system, including an objective mounted on said movable portion, for focusing laser light into a spot of said disk; (d) a photodetector cooperable with said optical system for receiving laser light reflected from said disk and producing reading signals; (e) a position sensor for producing position signals that establish the position of said spot relative to a track; (f) a servo tracking circuit responsive to said position signals for producing a driving signal; (g) actuator means for moving said movable portion on said optical pickup to thereby displace said objective in a tracking direction in response to said driving signal; and (h) said position sensor including means for establishing a parameter functionally related to the position of the movable portion on the optical pickup body, and means responsive to said parameter for generating said position signals, said means for establishing a parameter includes opposed Hall effect elements mounted on said movable portion facing permanent magnets mounted on said optical pickup body, said parameter being the Hall voltage generated by said Hall effect elements, and a Hall effect generator responsive to said Hall elements for producing Hall voltages constituting said position signals.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-10 | 1994-03-12 | 1994-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-10 | 1998-03-12 | 1998-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-10 | 2002-03-12 | 2002-09-11 | $7700.00 | Window Closed / Lapsed |