Disk drive with off-track write prevention
US6496315B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 24, 1999 |
| Grant date | Dec 17, 2002 |
| Priority date | — |
| Expiry date | Nov 24, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59688
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A disk drive with the capability to prevent off-track writing with reduced false triggering is described. An improved method of predicting the position of a head is used to determine whether the head is on or off-track. A position error signal at an nth servo position Pn and a velocity Vn at the nth servo position (Vn=Pn−Pn−1) are calculated using values read at the nth and n−1 head positions. Based on these Pn and Vn and on the output of the servo controller at the nth servo position Un, the predicted PESn+1 is calculated as:Predicted PESn+1=Pn+Vn+kUnwhere k is a constant.Data is inhibited from being written between the nth servo position and the (n+1) servo position, when absolute values of the calculated Pn, Vn, and predicted PESn+1 meet any condition of the following conditions (1) through (3): (1) |Pn|>C1, (2) |Vn|>C2, and (3) |Predicted PESn+1>C3 where C1, C2, and C3 are constants determined for the embodiment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.