EP0213549A2
Expired / Lapsed
EP
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Automatic tracking system for magnetic recording and reproducing apparatus
Assignee: Hitachi Ltd
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Filing: 1986-08-20
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Granted: —
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Expires: 2006-08-20
Abstract
Abstract In an automatic tracking system for a magnetic recording and reproducing apparatus wherein tracking is controlled so as to increase an amplitude of a reproduced signal which is delivered from a rotary head (4, 4') for reproducing a track recorded by a helical scan system, the amplitudes of the reproduced signal are detected at a plurality of points of time within one rotational cycle of the rotary head (4, 4'), and the tracking is controlled so as to increase a minimum value among the detected values at the plurality of points of time.
Inventors
- 👤 Hideo Nishijima
- 👤 Kaneyuki Okamoto
- 👤 Katsuhiko Goto
- 👤 Hiroshi Usami
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 21:02
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/18; G11B15/46; G11B15/467; G11B15/4673; G11B15/4675
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
136 words
An automatic tracking system for a magnetic recording and reproducing apparatus, comprising: tracking adjustment means to change a phase of a scanning locus of a rotary head in a widthwise direction of a track, said rotary head reproducing the track recorded by a helical scan system; a level detector which detects an amplitude of a reproduced signal delivered from said rotary head; and a data processing circuit which controls said tracking adjustment means so as to increase an output of said level detector; said level detector detecting the amplitudes of the reproduced signal at a plurality of points of time within an interval of a predetermined cycle, said data processing circuit controlling said tracking adjustment means so as to increase a minimum value among detected values at the plurality of points of time within the interval.
Claim 2
Dependent Claim
136 words
An automatic tracking system for a magnetic recording and reproducing apparatus, comprising: tracking adjustment means to change a phase of a scanning locus of a rotary head in a widthwise direction of a track, said rotary head reproducing the track recorded by a helical scan system; a level detector which detects an amplitude of a reproduced signal delivered from said rotary head; and a data processing circuit which controls said tracking adjustment means so as to increase an output of said level detector; said level detector detecting the amplitudes of the reproduced signal at a plurality of points of time within an interval of a predetermined cycle, said data processing circuit controlling said tracking adjustment means so as to increase a minimum value among detected values at the plurality of points of time within the interval.
Claim 3
Dependent Claim
23 words
An automatic tracking system according to claim l, wherein the interval of the predetermined cycle is one rotational cycle of said rotary head.
Claim 4
Dependent Claim
68 words
An automatic tracking system according to claim l, wherein said level detector comprises: a first detector which detects a high level of the reproduced signal amplitude delivered from said rotary head; and a second detector which has a time constant greater than that of said first detector and which detects a low level of an output of said first detector over one rotational cycle of said rotary head.
References Cited (Backward Citations)
No citation records indexed.
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