EP0353767A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Detecting sector servo information in a disk system
Assignee: Fujitsu Ltd
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Filing: 1989-08-04
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Granted: —
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Expires: 2009-08-04
Abstract
Abstract A sector servo method of detecting sector servo information in a disk system, wherein the sector servo information comprises at least one auxiliary confirming code pattern in addition to conventionally used sector mark, track address and servo position information. Generation of a group of timing signals to detect a selected portion of the sector servo information is adjusted, such that the timing signal is synchronous with the selected portion of the sector servo information, by detecting the auxiliary confirming code pattern. Synchronisation is performed by loading a predetermined number into counter circuit means when the auxiliary confirming code pattern is detected. Disk system apparatus operable under this method is provided.
Inventors
- 👤 Teruaki C/O Fujitsu Limited Emori
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 11:54
CPC Classifications
G; G11; G11B; G11B20/00; G11B5/00; G11B5/48; G11B5/58; G11B5/596; G11B5/59633; G11B5/59655
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
97 words
A method of detecting sector servo information from a signal reproduced by a magnetic head in a disk system, wherein the sector servo information is recorded in servo sectors interspersed with data sectors on the same tracks on a disk surface, the sector servo information comprising a sector mark, a track address, and servo position information, and wherein means for detecting the sector mark are provided, said method comprising:- providing at least one auxiliary confirming code pattern in the servo sector, detecting said auxiliary confirming code pattern from the reproduced signal, and detecting the sector servo information.
Claim 2
Independent Claim
97 words
A method of detecting sector servo information from a signal reproduced by a magnetic head in a disk system, wherein the sector servo information is recorded in servo sectors interspersed with data sectors on the same tracks on a disk surface, the sector servo information comprising a sector mark, a track address, and servo position information, and wherein means for detecting the sector mark are provided, said method comprising:- providing at least one auxiliary confirming code pattern in the servo sector, detecting said auxiliary confirming code pattern from the reproduced signal, and detecting the sector servo information.
Claim 3
Dependent Claim
88 words
A method as claimed in claim 1, wherein means are provided for generating a group of timing signals, said timing signals at least comprising a timing signal synchronous with detection of the sector mark, and said method comprising:- adjusting timing of the generation of members of said group of timing signals when the auxiliary confirming code pattern is detected, whereby the synchronous condition of a timing signal with a selected portion of the sector servo information is obtained, the sector servo information being detected utilising said timing signals.
Claim 4
Dependent Claim
76 words
A method as claimed in claim 2, comprising:- detecting the sector mark and said auxiliary confirming code pattern from the reproduced signal, adjusting timing of the generation of members of said group of timing signals when the sector mark and/or auxiliary confirming code pattern are detected, whereby the synchronous condition of a timing signal with a selected portion of the sector servo information is obtained, and the sector servo information being detected utilising said timing signals.
Claim 5
Dependent Claim
19 words
A method as claimed in claim 1, 2 or 3, comprising providing a plurality of auxiliary confirming code patterns.
Claim 6
Dependent Claim
58 words
A method as claimed in claim 4, wherein two auxiliary confirming code patterns are provided, a first auxiliary confirming code pattern comprising a plurality of track address codes, a plurality of supplementary codes interspersed among the track address codes, and check bits, and a second auxiliary confirming code pattern comprising a plurality of AGC codes and timing bits.
Claim 7
Dependent Claim
25 words
A method as claimed in claim 4, wherein each of said auxiliary confirming code patterns is formed separated from each other in the servo sector.
Claim 8
Dependent Claim
80 words
A method as claimed in claim 2 or 3, or claim 4, 5 or 6 when read as appended to claim 2 or 3, wherein said means of generating a group of timing signals comprises a counter circuit and a timing signal generator circuit, and wherein said timing adjustment of the generation of said group of timing signals is performed by loading a predetermined number to the counter circuit at a time when the auxiliary confirming code pattern is detected.
Claim 9
Dependent Claim
56 words
A method as claimed in claim 7 when read as appended to claim 3, directly or indirectly, wherein said timing adjustment of the generation of said group of timing signals is performed by loading a predetermined number to the counter circuit at each time when the sector mark and the auxiliary confirming code pattern are detected.
Claim 10
Dependent Claim
46 words
A method as claimed in claim 8, wherein said timing adjustment comprises first timing adjustment when the sector mark and the auxiliary confirming code pattern are detected and second timing adjustment when either one of the sector mark and the auxiliary confirming code pattern is detected.
Claim 11
Dependent Claim
50 words
A method as claimed in claim 9, wherein said first timing adjustment, performed by loading the predetermined number into the counter circuit, further comprises subsequent identification of each of the sector mark and the auxiliary confirming code pattern at a time when the counter circuit counts said respective predetermined number.
Claim 12
Independent Claim
45 words
A method as claimed in any preceding claim, wherein said track address is encoded in a Gray code sequence and said auxiliary confirming code pattern includes a plurality of supplementary codes, for example of value "1", interspersed among the codes of the Gray code sequence.
Claim 13
Dependent Claim
89 words
Disk system apparatus having a disk on a disk surface of which sector servo information is recorded in servo sectors interspersed between data sectors on the same tracks, and having a magnetic head for reproducing information recorded on said disk surface, the sector servo information comprising a sector mark, a track address, and servo position information, and having means for detecting the sector mark, wherein at least one auxiliary confirming code pattern is provided in the servo sector and means are provided for detecting said auxiliary confirming code pattern.
Claim 14
Dependent Claim
89 words
Disk system apparatus having a disk on a disk surface of which sector servo information is recorded in servo sectors interspersed between data sectors on the same tracks, and having a magnetic head for reproducing information recorded on said disk surface, the sector servo information comprising a sector mark, a track address, and servo position information, and having means for detecting the sector mark, wherein at least one auxiliary confirming code pattern is provided in the servo sector and means are provided for detecting said auxiliary confirming code pattern.
Claim 15
Dependent Claim
72 words
Apparatus as claimed in claim 12, further comprising means for generating a group of timing signals, and for generating at least one of those timing signals synchronously with detection of the sector mark, and means for adjusting timing of generation of members of said group when the auxiliary confirming code pattern is detected, whereby the synchronous condition of a timing signal with a selected portion of the sector servo information is obtained.
Claim 16
Dependent Claim
26 words
Apparatus as claimed in claim 13, wherein the means for adjusting timing are operable when the sector mark and/or the auxiliary confirming code pattern is detected.
Claim 17
Dependent Claim
22 words
Apparatus as claimed in claim 12, 13 or 14, having features providing operation in accordance with any of claims 4 to 11.
References Cited (Backward Citations)
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