Patent US4314291A successfully refreshed from Google Patents.
US4314291A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-compensating device for a magnetic disc apparatus
Assignee: Toshiba Corp
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Filing: 1979-11-01
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Granted: 1982-02-02
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Expires: 1999-11-01
Abstract
Abstract Disclosed is a self-compensating device for a magnetic disc apparatus with a velocity servo system in which a change of the characteristic of an actuator for positioning a read/write transducer is automatically compensated by the combination of a control means and a compensator. While supplying a given velocity command signal to the velocity servo system, the control means measures the motion of the transducer by using a track detector and adjusts the compensator on the basis of the result of the measurement.
Inventors
- 👤 Yasutaka Oda
- 👤 Hiromi Hamaoka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:28
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/5526; G11B5/553
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
249 words
Self-compensating apparatus for a magnetic disc apparatus comprising: (a) magnetic disc means with a number of data tracks and a number of servo tracks, said data tracks being concentrically arranged on a surface of the magnetic disc means and said servo tracks being concentrically arranged on a surface of said magnetic disc means; (b) read/write transducer means for reading out data from or writing data into said data tracks; (c) servo transducer means for reading out servo data from said servo tracks; (d) actuator means for reciprocally moving said read/write and servo transducer means across said data and servo tracks; (e) track detector means responsive to an output signal of said servo transducer means to produce a pulse each time said servo transducer means crosses a servo track; (f) velocity detecting means which detects the velocity of said servo transducer means to produce a velocity signal; (g) velocity error detector means responsive to said velocity signal and a velocity command signal to produce a velocity error signal; (h) compensator means responsive to said velocity error signal to produce a compensated velocity error signal, thereby compensating a characteristic of said actuator means; (i) drive means responsive to said compensated velocity error signal to accelerate or decelerate said actuator means so as to make compensated velocity error signal small; and (j) control means for supplying said velocity command signal, and for adjusting said compensator means responsive to said output pulses of said track detector means and a given velocity command signal.
Claim 2
Dependent Claim
249 words
Self-compensating apparatus for a magnetic disc apparatus comprising: (a) magnetic disc means with a number of data tracks and a number of servo tracks, said data tracks being concentrically arranged on a surface of the magnetic disc means and said servo tracks being concentrically arranged on a surface of said magnetic disc means; (b) read/write transducer means for reading out data from or writing data into said data tracks; (c) servo transducer means for reading out servo data from said servo tracks; (d) actuator means for reciprocally moving said read/write and servo transducer means across said data and servo tracks; (e) track detector means responsive to an output signal of said servo transducer means to produce a pulse each time said servo transducer means crosses a servo track; (f) velocity detecting means which detects the velocity of said servo transducer means to produce a velocity signal; (g) velocity error detector means responsive to said velocity signal and a velocity command signal to produce a velocity error signal; (h) compensator means responsive to said velocity error signal to produce a compensated velocity error signal, thereby compensating a characteristic of said actuator means; (i) drive means responsive to said compensated velocity error signal to accelerate or decelerate said actuator means so as to make compensated velocity error signal small; and (j) control means for supplying said velocity command signal, and for adjusting said compensator means responsive to said output pulses of said track detector means and a given velocity command signal.
Claim 3
Dependent Claim
213 words
In a magnetic disc apparatus comprising magnetic disc means with a number of data tracks concentrically arranged on a surface thereof, read/write transducer means for reading out data from or writing data into said data tracks, actuator means for reciprocally moving said read/write transducer means across said data tracks, velocity detecting means for detecting the velocity of said transducer means to produce a velocity signal, velocity error detector means responsive to said velocity signal and a velocity command signal to produce a velocity error signal and drive means responsive to said velocity error signal to accelerate or decelerate said actuator means so as to make said velocity error signal small; self-compensating apparatus for compensating for a characteristic of said actuator means, wherein said velocity error detector means is responsive to said velocity signal and a velocity command signal to produce said velocity error signal, and comprising compensator means responsive to said velocity error signal to produce a compensated velocity error signal, said drive means being responsive to said compensated velocity error signal, means for detecting the position of the transducer means relative to the data tracks, and control means for supplying said velocity command signal, and for adjusting said compensator means responsive to said means for detecting and a given velocity command signal.
Claim 4
Dependent Claim
213 words
In a magnetic disc apparatus comprising magnetic disc means with a number of data tracks concentrically arranged on a surface thereof, read/write transducer means for reading out data from or writing data into said data tracks, actuator means for reciprocally moving said read/write transducer means across said data tracks, velocity detecting means for detecting the velocity of said transducer means to produce a velocity signal, velocity error detector means responsive to said velocity signal and a velocity command signal to produce a velocity error signal and drive means responsive to said velocity error signal to accelerate or decelerate said actuator means so as to make said velocity error signal small; self-compensating apparatus for compensating for a characteristic of said actuator means, wherein said velocity error detector means is responsive to said velocity signal and a velocity command signal to produce said velocity error signal, and comprising compensator means responsive to said velocity error signal to produce a compensated velocity error signal, said drive means being responsive to said compensated velocity error signal, means for detecting the position of the transducer means relative to the data tracks, and control means for supplying said velocity command signal, and for adjusting said compensator means responsive to said means for detecting and a given velocity command signal.
Claim 5
Dependent Claim
87 words
A self-compensating apparatus according to claim 2, wherein said magnetic disc means includes a number of servo tracks on a surface thereof, said self-compensating apparatus comprising servo transducer means for reading out servo data from said servo tracks, said means for detecting being responsive to an output signal of said servo transducer means to produce a pulse each time said servo transducer means crosses a servo track, said control means being responsive to said output pulses and said given velocity command signal for adjusting said compensator means.
Claim 6
Dependent Claim
35 words
A self-compensating apparatus according to claim 1 or 3, wherein said drive means feeds a fixed current to said actuator means during a period in which said compensated velocity error signal exceeds a given value.
Claim 7
Dependent Claim
18 words
A self-compensating apparatus according to claim 1 or 3, wherein said control means includes a programmed data processor.
Claim 8
Dependent Claim
28 words
A self-compensating apparatus according to claim 1 or 3, wherein said compensator means includes a variable gain amplifier of which the gain is controlled by said control means.
Claim 9
Dependent Claim
56 words
A self-compensating apparatus according to claim 6, wherein said control means responsive to said output pulses of said position detector means measures the time taken for said transducer means to move a given distance and adjusts the gain of said variable gain amplifier in accordance with a difference between the measured value and a pregiven value.
Claim 10
Dependent Claim
31 words
A self-compensating apparatus according to claim 7, wherein the acceleration of said transducer means is kept substantially at a fixed value during passage of said transducer means over said given distance.
Claim 11
Dependent Claim
29 words
A self-compensating apparatus according to claim 6, wherein said control means adjusts the gain of said variable gain amplifier each time power is supplied to said magnetic disc apparatus.
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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) | 1985-02-01 | 1985-08-03 | 1986-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-02-01 | 1989-08-03 | 1990-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-02-01 | 1993-08-03 | 1994-02-02 | $7700.00 | Window Closed / Lapsed |