Self-servowriting disk drive and method
US5448429A · kind A · utility
Inventors
Key dates
| Filing date | Jul 12, 1994 |
| Grant date | Sep 5, 1995 |
| Priority date | — |
| Expiry date | Jul 12, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59633
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An embodiment of the present invention is a disk drive comprising a rotating disk with a recording surface, a transducer in communication with the surface and swept radially over the surface by a servo-actuator, a variable gain read amplifier connected to the transducer, an analog-to-digital converter (ADC) attached to the variable gain amplifier, an erase frequency oscillator coupled to the transducer for erasing of the disk surface, a memory for storing digital outputs appearing at the ADC, and a controller for signaling the servo-actuator to move to such radial positions that result in transducer read amplitudes that are a percentage of previous read amplitudes represented in the digital memory. Bit-synchronism between tracks is maintained by writing an initial clock track with closure and then writing a next clock track including a regular sequence of clock bursts a half-track space offset such that the initial clock track can be read in between writing clock bursts and the read signal is used to frequency-lock an oscillator which is used as a reference for the writing of clock bursts of the next track. A checkerboard pattern of clock bursts is thus created. All subsequent trac…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.