Browse Prior Art Database

On Data Track Servoing

IP.com Disclosure Number: IPCOM000088064D
Original Publication Date: 1977-Apr-01
Included in the Prior Art Database: 2005-Mar-04
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Schneider, J: AUTHOR [+2]

Abstract

In a magnetic disk file (Fig. 1), magnetic disk 1 is rotated about axis 2 so that signals are read from data track 3 by magnetic head unit 4. Head positioning motor 8, via access arm 5, causes magnetic head unit 4 to access a selected data track from which data/servo signals are transferred to data/servo signal read circuits for the data track following of magnetic head unit 4.

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On Data Track Servoing

In a magnetic disk file (Fig. 1), magnetic disk 1 is rotated about axis 2 so that signals are read from data track 3 by magnetic head unit 4. Head positioning motor 8, via access arm 5, causes magnetic head unit 4 to access a selected data track from which data/servo signals are transferred to data/servo signal read circuits for the data track following of magnetic head unit 4.

Magnetic head unit 4 (Fig. 2) carries magnetic read/write head 17 whose pole pieces are arranged orthogonally to the direction of track movement, so that data bits 12 are recorded on both sides of the center line of data track 3. The magnetic disk is coated with anisotropic magnetic material having an easy direction orthogonal to the plane of the disk surface. Magnetic head unit 4 also carries magnetoresistive head 11 which, at the trailing edge of magnetic head 17, is centrally arranged with respect to the magnetic head track line.

During read/write operations of magnetic head 17, magnetoresistive head 11 scans data track 3 for reading servo signals. Waveform 13 (Fig. 2A) represents data signals Ud which are read from data recording bits 12 on data track 3. Waveform 14 (Fig. 2B) is the characteristic of magnetoresistive output signal Rc when magnetic head unit 4 is accurately adjusted to the center line of data track
3. This waveform is derived from data bits which deliver equal amounts of opposite magnetization to magnetoresistive head 11. When the magnetic head deviates from the...