Disk drive with capacitance sensing of disk vibration and feedforward control for removal of read/write head track misregistration
US7012777B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 2004 |
| Grant date | Mar 14, 2006 |
| Priority date | — |
| Expiry date | Sep 30, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59627
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A data recording disk drive has a plurality of capacitive sensors, each sensor facing a surface of an associated disk, a capacitance sensing circuit for converting the sensed capacitance to a voltage representative of the distance between the sensor and the disk surface, and a feedforward controller that receives the voltage signal. The feedforward controller has a transfer function with gain and phase characteristics designed to match the transfer function from the out-of-plane disk vibration to the position of the read/write head while accounting for the effects of the sensor dynamics and the dynamics of the actuator. The output from the feedforward controller is combined with the output from the disk drive's servo feedback controller so that the effects of disk vibration on track misregistration of the head are removed from the control signal to the actuator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.