US4607355A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drive system
Assignee: Ricoh Co Ltd
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Filing: 1983-10-28
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Granted: 1986-08-19
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Expires: 2003-10-28
Abstract
Abstract A drive system for use in an optical disk file device has a multipolar motor such as a three-phase linear DC motor for positionally controlling a read/write head and driving the same to track an optical disk. Selection of the coils of the motor and phase switching of the coils are stopped while the drive system is in the tracking mode.
Inventors
- 👤 Hiroshi Koide
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:18
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/08; G11B7/085; G11B7/0857; G11B7/08582; G11B7/08588; G11B7/08505; G11B7/08517; G11B7/08529; G11B7/09; G11B7/0901
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
221 words
A drive system for use in an optical disk file device having a read/write head for reading and writing information from and onto a track of an optical disk, comprising: (a) a multipolar motor having a plurality of coils each selectively energizable by a current signal of a selected phase direction, the phase directions of the current signals for said coils being switched in order to drive said read/write head to a target track location during a positioning mode, the phase switching of said coils being prevented when said read/write head is to be maintained at the target track location during a tracking mode; (b) phase switching means for providing a phase switching signal for energizing said coils during said positioning mode; (c) position error detecting means for detecting a difference in the position of said read/write head relative to the target track location and for providing an output when said read/write head has arrived at the target track location; (d) tracking control means for providing tracking control signals without phase switching to said coils for maintaining said read/write head in the target track location during said tracking mode; and (e) switching means for switching the energizing of said coils from said phase switching means to said tracking control means in response to said output of said position error detecting means.
Claim 2
Dependent Claim
221 words
A drive system for use in an optical disk file device having a read/write head for reading and writing information from and onto a track of an optical disk, comprising: (a) a multipolar motor having a plurality of coils each selectively energizable by a current signal of a selected phase direction, the phase directions of the current signals for said coils being switched in order to drive said read/write head to a target track location during a positioning mode, the phase switching of said coils being prevented when said read/write head is to be maintained at the target track location during a tracking mode; (b) phase switching means for providing a phase switching signal for energizing said coils during said positioning mode; (c) position error detecting means for detecting a difference in the position of said read/write head relative to the target track location and for providing an output when said read/write head has arrived at the target track location; (d) tracking control means for providing tracking control signals without phase switching to said coils for maintaining said read/write head in the target track location during said tracking mode; and (e) switching means for switching the energizing of said coils from said phase switching means to said tracking control means in response to said output of said position error detecting means.
Claim 3
Dependent Claim
49 words
A drive system according to claim 1, further comprising latching means for preventing said phase switching signal from being provided to said coils for phase switching of said coils, said latching means being enabled by said switching means in response to said output of said position error detecting means.
Claim 4
Dependent Claim
168 words
A drive system according to claim 2, wherein said motor is a linear motor having a linear array of permanent magnets arranged for addressing the tracks of the optical disk and said coils are mounted on a carriage carrying said read/write head and adapted to be driven relative to said permanent magnets, said drive system further comprising a position detector for providing a signal indicating the position of said read/write head as it is driven across the tracks of the optical disk, said phase switching means including a phase switching reversible counter for maintaining an address count of the position of said read/write head based upon the output of said position detector and providing said phase switching signal for phase switching said coils in correspondence to the position of said read/write head as it is driven during the positioning mode, and a phase switching encoder for receiving said phase switching signal through said latching means and providing respective current signals of the corresponding phase directions to said coils.
Claim 5
Dependent Claim
111 words
A drive device according to claim 3, further comprising speed control means including a speed signal generator for converting said signal of said position detector into a speed voltage signal proportional to the speed of movement of said read/write head, a D/A converter for converting the output of said position error detecting means to a difference voltage signal corresponding to the detected position difference from the target track location, and a comparator for subtracting said speed voltage signal from said difference voltage signal to provide an output voltage level to said coils, so that said read/write head is driven at a progressively reduced speed as it approaches the target track location.
Claim 6
Dependent Claim
61 words
A drive device according to claim 4, further comprising second switching means for switching off said speed control means and switching on said signal of said position detector to energize said coils in a fine adjustment so as to bring said read/write head to an exact position in the target track location during a position control mode of a predetermined duration.
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) | 1989-08-18 | 1990-02-17 | 1990-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-18 | 1994-02-17 | 1994-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-18 | 1998-02-17 | 1998-08-19 | $7700.00 | Window Closed / Lapsed |