Head positioning system for a disk drive during a power down condition
US6560057B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1999 |
| Grant date | May 6, 2003 |
| Priority date | — |
| Expiry date | Apr 30, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B21/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A disk drive includes a read/write head mounted on an actuator, a disk having an inner diameter region and an outer diameter region, the head being radially movable by the actuator between the inner diameter region and the outer diameter region. An unload ramp is positioned at the outer diameter region. A controller outputs control signals upon sensing a power down condition. A feedback circuit is adapted to sense a back emf generated by the actuator and to use the back emf to apply a counter-acting voltage to the actuator that tends to bring the actuator to a stop. A switch is responsive to the control signals to (i) connect the feedback circuit to the actuator to enable the actuator to be brought to a stop while the disk continues to rotate and (ii) for then causing the actuator to move the head to the unload ramp. The switch further applies a voltage which causes the actuator to bring the head to the inner diameter region of the disk, before causing the actuator to move the head to the unload ramp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.