Browse Prior Art Database

Constant Length Sector Servo

IP.com Disclosure Number: IPCOM000087046D
Original Publication Date: 1976-Dec-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Aziz, RA: AUTHOR

Abstract

Some record storage apparatus of the rotating disk type employ sector servoing for locating record tracks and for track-following purposes. The term "sector servoing" means that servo signals are circumferentially interleaved with data signals, for example, in 100 circumferential positions around the disk. Such sector servos have a radial extent equal to the recording area between concentric circles Di and Do. In disk storage apparatus a single-gap transducer is often employed.

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Constant Length Sector Servo

Some record storage apparatus of the rotating disk type employ sector servoing for locating record tracks and for track-following purposes. The term "sector servoing" means that servo signals are circumferentially interleaved with data signals, for example, in 100 circumferential positions around the disk. Such sector servos have a radial extent equal to the recording area between concentric circles Di and Do. In disk storage apparatus a single-gap transducer is often employed.

However, in certain applications a dual-gap head has certain advantages. Such dual-gap head can include an erase gap E in an upstream position, followed by a read/write gap R/W in a trailing position'. The distance between the gaps is termed the intergap distance, which is represented on the illustrated disk as the spacing between the E line and the R/W line. As in single-gap disk storage apparatus, the dual-gap head H moves along a radial motion line from an access of rotation toward the outer circumference of the disk. The radial motion line in a preferred form of this invention disects the space between the E line and R/W line.

The usual sector servo is defined by radial lines R1 and R2. This enables a constant frequency servo signal to be employed in the sector servoing operation. However, certain control functions with respect to the E gap and the R/W gap arise when such sector servoing is employed. For simplifying switching and enabling the erasing while writing, the sector servo is designed to have a ...