Soft sensor for operating shock in a disc drive
US7349174B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 9, 2002 |
| Grant date | Mar 25, 2008 |
| Priority date | — |
| Expiry date | Feb 20, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/20
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of preventing a write operation to a disc in a disc drive during a shock event without the use of a separate shock sensor comprises steps of monitoring an actuator voice coil motor (VCM) control plant output signal, generating an actuator voice coil motor (VCM) plant model module output signal, comparing the VCM plant model module output signal to the VCM control plant module output signal to produce a difference signal, and triggering a write protect gate if the difference signal exceeds a predetermined threshold value. The system comprises a voice coil motor (VCM) control plant module sensitive to a shock event providing a VCM control plant module output, a voice coil motor (VCM) plant model module initially insensitive to the shock event producing a VCM plant model module output, a first comparator module coupled to receive the VCM control plant module output and the VCM plant model module output, operable to generate a difference signal between the model plant module output and the VCM control plant module output, and a triggering module receiving the difference signal for generating a write protect gate signal if the difference signal exceeds a predetermined shock thr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.