Method and system for GMR sensor reset pulse application
US6324029A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 1998 |
| Grant date | Nov 27, 2001 |
| Priority date | — |
| Expiry date | Jun 29, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/3996
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and system are disclosed for controlling the application of a reset voltage pulse to a GMR sensor in a direct-access storage device (DASD), such that existing data is not damaged or altered. Each sensor is positioned or parked at a location reserved for reset pulse application, where no valid data is stored. A complex interrelated set of commands is then initiated, and upon completion of the entire set of interrelated commands, a reset pulse is applied to the GMR sensor. Any variation or interruption in the complex interrelated set of commands will result in a disarming of the reset pulse circuitry, effectively preventing an accidental or inadvertent application of the GMR reset pulse. Alternately, a group of GMR sensors each may be tracked to a reserve track, forming a reserve cylinder. Servo marks on the reserve track are sensed by a selected sensor and utilized to ensure no valid data is present. An alternate sensor is then temporarily selected, and a reset pulse is applied, timed to avoid occurrence over a servo mark.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.