US4075667A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for aligning read/write heads in a disc recorder
Assignee: Unisys Corp
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Filing: 1975-12-17
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Granted: 1978-02-21
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Expires: 1995-12-17
Abstract
Abstract In a magnetic disc recorder utilizing a servo head to generate a feedback signal for the positioning of the heads on the recording disc, a method for aligning the read/write heads with the servo heads by eliminating substantially all of the effects of head movement occurring during the head alignment procedure.
Inventors
- 👤 Andrew M. Rose
- 👤 Brian Paul Tremaine
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:21
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/56
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
155 words
In a recording device for recording data on a medium and having a plurality of read/write heads and a servo head mounted for simultaneous movement on a carriage effected by energization of an actuator acting responsive to a servo signal detected by the servo head, and wherein the read/write heads are mounted in a manner to allow fine position adjustment relative to the servo head; the method of aligning the read/write heads relative to the servo head comprising the steps of: placing on the recording device a medium having prerecorded aligned signals positioned to be detected by the read/write heads and servo head simultaneously to indicate track positions; detecting the signals read by the servo head and the read/write heads; subtracting the signals of one read/write head from the signal of the servo head to generate a differential signal; and manually fine adjusting the position of said one read/write head to minimize said differential signal.
Claim 2
Dependent Claim
155 words
In a recording device for recording data on a medium and having a plurality of read/write heads and a servo head mounted for simultaneous movement on a carriage effected by energization of an actuator acting responsive to a servo signal detected by the servo head, and wherein the read/write heads are mounted in a manner to allow fine position adjustment relative to the servo head; the method of aligning the read/write heads relative to the servo head comprising the steps of: placing on the recording device a medium having prerecorded aligned signals positioned to be detected by the read/write heads and servo head simultaneously to indicate track positions; detecting the signals read by the servo head and the read/write heads; subtracting the signals of one read/write head from the signal of the servo head to generate a differential signal; and manually fine adjusting the position of said one read/write head to minimize said differential signal.
Claim 3
Dependent Claim
67 words
In the method of aligning the read/write heads as defined in claim 1 including providing means for supplying only the low frequency servo signals to the actuator to thereby make said actuator more resistant to movement resulting from external forces acting on said carriage; and energizing said means to make the actuator more resistant to movement when the position of said one read/write head is being adjusted.
Claim 4
Dependent Claim
62 words
In the method as defined in claim 2, said means to make said actuator more resistant to movement comprising a circuit for receiving and storing the servo signal when said servo signal is in the lower frequency ranges and for supplying said lower frequency signals to control energization of said actuator when the position of said one read/write head is being adjusted.
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) | 1981-02-20 | 1981-08-22 | 1982-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-20 | 1985-08-22 | 1986-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-20 | 1989-08-22 | 1990-02-21 | $7700.00 | Window Closed / Lapsed |