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DISPERSED SERVO TRACK COUNTING SCHEME

IP.com Disclosure Number: IPCOM000024812D
Original Publication Date: 1982-Apr-30
Included in the Prior Art Database: 2004-Apr-04
Document File: 2 page(s) / 100K

Publishing Venue

Xerox Disclosure Journal

Abstract

This disclosure takes advantage of the embedded sector servo scheme which does not use a dedicated servo surface for counting track crossings, thereby gaining more data recording capacity. It overcomes the inability of that scheme to count track crossings by having a full circumference servo track placed after each ten or twenty data tracks. In this way, positive location of the recording heads is known for the longer seeks. A counter can be set up to count track crossings. Those dispersed servo tracks may be recorded with a frequency not within the normal frequency spectrum of the data recording or the sector servo recording, thus making the identification of these dispersed servo tracks easier.

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Page 1 of 2

XEROX DISCLOSURE JOURNAL

DISPERSED SERVO TRACK COUNTING SCHEME US. C1. 346/137 Richard J. Elliott

Proposed Classification

Int. Cl. Gold 15/24

/SERVO SECTOR, TYP

DATA TRACK tl1

WTA TRACK #2

ETC.

DISPERSED SERVO TRACK WITH GREATER
AREAL EFFICIENCY

"X" DATA TRACKS

SERVO SECTOR, TYP.

DATA TRACK, TYP.

DISPERSED, FULL CIRCUMFERENTIAL SERVO TRACK, REPEATED EVERY "X" NUMBER OF WTA TRACKS

FIG 2

Volume 7 Number 2 March/April 1982 91

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Page 2 of 2

DISPERSED SERVO TRACK COUNTING SCHEME (Cont'd)

This disclosure takes advantage of the embedded sector servo scheme which does not use a dedicated servo surface for counting track crossings, thereby gaining more data recording capacity. It overcomes the inability of that scheme to count track crossings by having a full circumference servo track placed after each ten or twenty data tracks. In this way, positive location of the recording heads is known for the longer seeks. A counter can be set up to count track crossings. Those dispersed servo tracks may be recorded with a frequency not within the normal frequency spectrum of the data recording or the sector servo recording, thus making the identification of these dispersed servo tracks easier.

The dispersement of these full circumference servo tracks would relate to the number of tracks remaining away from the desired track when the recording transducers had slowed down to point that a sector servo is encountered at every data t...