US5086419A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical disk apparatus for controlling second optical beam based on bias information
Assignee: Panasonic Holdings Corp
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Filing: 1990-08-31
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Granted: 1992-02-04
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Expires: 2010-08-31
Abstract
Abstract When a light beam of a reference optical head correctly tracks on the center of a proper track, deviation, due to an optical head assembling error or an optical disk eccentrically, of a light beam of a non-reference optical head from the center of said proper track is memorized in advance as bias information. At a time of a seek control or a track lump control, the non-reference optical head is controlled to move along a track with said bias information, so that not only the reference optical head but also the non-reference optical head correctly track on the proper aimed track, when a seek control or a track jump control is performed. This invention enables both the light beam of the reference optical head and the light beam of the non-reference optical head to correctly track on a proper track without being affected by neither any optical head assembling error nor any optical disk eccentricity.
Inventors
- 👤 Shigenori Yanagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:24
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/12; G11B7/14; G11B7/08; G11B7/085; G11B7/08505
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
243 words
An optical disk apparatus having a first optical head equipped with a first lens actuator for movement control of a first light beam projected to a location on a track of an optical disk and a second optical head equipped with a second lens actuator for controlling the movement of a second light beam projected to another location of an optical disk different form the location projected to by said first light beam, comprising: a first track servo control part means for performing control so that the first light beam is projected to a track and for generating a control signal; a second track servo control part means for performing control so that the second light beam is projected to a track; a positioner means for controlling the movement of the first and second optical heads in response to the control signal; a bias information memory part means for storing bias information including information pertaining to a position of the second optical head relative to said first optical head obtained when said first and second track servo control part means control the light beams of both said first and second optical heads to properly track on the same track; and means for enabling said second track servo control part means to control the position of the second optical head according to the bias information stored in said bias information memory part means when the first light beam is projected on a target track.
Claim 2
Dependent Claim
243 words
An optical disk apparatus having a first optical head equipped with a first lens actuator for movement control of a first light beam projected to a location on a track of an optical disk and a second optical head equipped with a second lens actuator for controlling the movement of a second light beam projected to another location of an optical disk different form the location projected to by said first light beam, comprising: a first track servo control part means for performing control so that the first light beam is projected to a track and for generating a control signal; a second track servo control part means for performing control so that the second light beam is projected to a track; a positioner means for controlling the movement of the first and second optical heads in response to the control signal; a bias information memory part means for storing bias information including information pertaining to a position of the second optical head relative to said first optical head obtained when said first and second track servo control part means control the light beams of both said first and second optical heads to properly track on the same track; and means for enabling said second track servo control part means to control the position of the second optical head according to the bias information stored in said bias information memory part means when the first light beam is projected on a target track.
Claim 3
Dependent Claim
58 words
The optical disk apparatus according to claim 1, wherein the bias information includes information pertaining to tracks of the optical disk, and wherein said second track servo control part controls the position of the second optical head according to the bias information corresponding to the target track when the first light beam is projected on the target track.
Claim 4
Dependent Claim
81 words
The optical disk apparatus according to claim 1, wherein the bias information includes information pertaining to any track within each block of the optical disk, when all the tracks of the optical disk are divided into more than one block, and wherein said second track servo control part controls the position of the second optical head according to the bias information of the block to which the target track belongs wherein the first light beam is projected on the target track.
Claim 5
Dependent Claim
79 words
The optical disk apparatus according to claim 1, wherein the bias information includes information pertaining to any track within any block of an optical disk, when all tracks of the optical disk are divided into two parts, and wherein said second track servo control part controls the position of the second optical head according to the bias information corresponding to the block to which the target track belongs when the first light beam is provided on the target track.
Claim 6
Dependent Claim
33 words
The optical disk apparatus according to claim 1, wherein the bias information includes information pertaining to each track of the optical disk and information pertaining to half a rotation of each said track.
Claim 7
Dependent Claim
47 words
The optical disk apparatus according to claim 1, wherein the bias information includes information pertaining to the location of the second lens actuator on the second optical head when the first light beam of the first optical head correctly tracks on a center of the target track.
Claim 8
Dependent Claim
39 words
The optical disk apparatus according to claim 1, wherein the bias information is stored in said bias information memory part means after one of power to the optical disk apparatus is turned on and an optical disk is exchanged.
Claim 9
Dependent Claim
100 words
The optical disk apparatus according to claim 1, wherein said optical disk apparatus further comprises means for controlling the first light beam and the second light beam to track on the same track by controlling the first light beam projected by the first optical head by said first track servo control part to correctly track on the center of a proper track, by performing a seek control or a track jump control, and by controlling the first light beam of the first optical head and the second light beam of the second optical head to track on the same track.
Claim 10
Dependent Claim
69 words
The optical disk apparatus according to claim 1, wherein said second lens actuator comprises a position sensor that detects a sense signal that corresponds to the amount of dislocation of the projected position of the second light beam from a track lead-in starting point along a track, and wherein said bias information memory part means obtains the predetermined bias information from the sense signal detected by said position sensor.
Claim 11
Dependent Claim
41 words
The optical disk apparatus according to claim 9, wherein said position sensor comprises a light emitting part and a light receiving device positioned on opposite sides of a fixed slit so that the light emitting part faces the light receiving device.
Claim 12
Dependent Claim
28 words
The optical disk apparatus according to claim 9, wherein said light receiving device comprises a two division light receiving device whose light receiving part is divided into two.
Claim 13
Dependent Claim
28 words
The optical disk apparatus according to claim 9, wherein said light receiving device comprises a four division light receiving device whose light receiving part is divided into four.
Claim 14
Dependent Claim
17 words
The optical disk apparatus according to claim 10, wherein said light receiving device comprises a photo diode.
Claim 15
Dependent Claim
22 words
The optical disk apparatus according to claim 1, wherein the bias information corresponds to at least one track of the optical disk.
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) | 1995-02-03 | 1995-08-05 | 1996-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-02-03 | 1999-08-05 | 2000-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-02-03 | 2003-08-05 | 2004-02-04 | $7700.00 | Window Closed / Lapsed |