EP0259039A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Magnetic disc apparatus
Assignee: Sony Corp
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Filing: 1987-08-13
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Granted: —
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Expires: 2007-08-13
Abstract
Abstract In a magnetic disc apparatus off-track quantities are stored corresponding to circular reference servo tracks formed in divided data areas on a magnetic disc (1) and, when positioning a magnetic head (3), the head (3) is shifted in dependence on the stored off-track quantity after having first been positioned by a head position detector (2, 5). Gradients of the variation in the off-track quantities with the temperature of the apparatus may be previously stored and, after the actual temperature has been detected by means of a temperature sensor (20), the off-track quantity relative to the reference servo track may then be corrected in accordance with the gradient of the off-track quantity for the relevant track at the detected temperature, whereby accurate tracking is achieved.
Inventors
- 👤 Susumu C/O Patent Division Hoshimi
- 👤 Takayasu C/O Patent Division Muto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 04:59
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/58; G11B5/596; G11B5/59627
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
152 words
A magnetic disc apparatus comprising: a magnetic disc (1) having a plurality of track groups thereon each of which comprises a plurality of data tracks and at least one reference track in which a servo signal is recorded; a transducer (3) for reading and writing data signals from and in said data tracks and for reading said servo signal from said reference track; and actuator means (4, 6) for positioning said transducer (3) over a desired one of said tracks; characterized by: means (8) for computing and generating a tracking error signal according to said servo signal read from said reference track; memory means (8) for storing said tracking error signal with respect to each of said track groups; and controller means (13, 14) for controlling said actuator means (4, 6) according to said stored tracking error signal corresponding to the track group within which said transducer (3) is to be positioned.
Claim 2
Dependent Claim
152 words
A magnetic disc apparatus comprising: a magnetic disc (1) having a plurality of track groups thereon each of which comprises a plurality of data tracks and at least one reference track in which a servo signal is recorded; a transducer (3) for reading and writing data signals from and in said data tracks and for reading said servo signal from said reference track; and actuator means (4, 6) for positioning said transducer (3) over a desired one of said tracks; characterized by: means (8) for computing and generating a tracking error signal according to said servo signal read from said reference track; memory means (8) for storing said tracking error signal with respect to each of said track groups; and controller means (13, 14) for controlling said actuator means (4, 6) according to said stored tracking error signal corresponding to the track group within which said transducer (3) is to be positioned.
Claim 3
Dependent Claim
46 words
Apparatus according to claim 1 further comprising position sensing means (2, 5) for sensing the position of said transducer (3) relative to said magnetic disc (1), and wherein said controller means (13, 14) is further controlled by the output of said position sensing means (2, 5).
Claim 4
Dependent Claim
55 words
Apparatus according to claim 2 wherein said position sensing means (2, 5) generates a pluarlity of periodic signals which are out of phase with each other and the periods of which correspond to a plurality of track pitches, and the number of reference tracks within one track group corresponds to the number of track pitches.
Claim 5
Dependent Claim
22 words
Apparatus according to claim 1 wherein each of said reference tracks is recorded in the centre of a respective said track group.
Claim 6
Dependent Claim
20 words
Apparatus according to claim 3 wherein said reference tracks are recorded in the centre of each of said track groups.
Claim 7
Dependent Claim
65 words
Apparatus according to claim 2 further comprising temperature detecting means (20) for detecting the temperature of said apparatus, and means (21, 2, 8) for compensating said tracking error signal according to the output of said temperature detecting means (20) and for generating a compensated error signal, and wherein said controller means (13, 14) controls said actuator means (4, 6) according to said compensated error signal.
Claim 8
Independent Claim
192 words
A method of positioning a transducer (3) relative to a magnetic disc (1) having a plurality of track groups thereon each of which comprises a plurality of data tracks and at least one reference track in which a servo signal is recorded, said transducer (3) reading and writing data signals from and in said data tracks and reading a servo signal from said reference track, said method being characterized by the steps of: positioning said transducer (3) over said reference track in each of said track groups; reading said servo signal from each of said reference tracks; computing and generating tracking error signals according to said read servo signals; storing said tracking error signals for each of said track groups in a memory means (8); receiving a seek command according to which said transducer (3) is to be positioned over a selected one of said data tracks; reading said tracking error signal corresponding to the track group within which said selected one of said data tracks is included from said memory means(8); and positioning said transducer (3) over said selected one of said data tracks according to said read tracking error signal.
Claim 9
Independent Claim
192 words
A method of positioning a transducer (3) relative to a magnetic disc (1) having a plurality of track groups thereon each of which comprises a plurality of data tracks and at least one reference track in which a servo signal is recorded, said transducer (3) reading and writing data signals from and in said data tracks and reading a servo signal from said reference track, said method being characterized by the steps of: positioning said transducer (3) over said reference track in each of said track groups; reading said servo signal from each of said reference tracks; computing and generating tracking error signals according to said read servo signals; storing said tracking error signals for each of said track groups in a memory means (8); receiving a seek command according to which said transducer (3) is to be positioned over a selected one of said data tracks; reading said tracking error signal corresponding to the track group within which said selected one of said data tracks is included from said memory means(8); and positioning said transducer (3) over said selected one of said data tracks according to said read tracking error signal.
References Cited (Backward Citations)
No citation records indexed.
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