Head mechanism control apparatus, disk drive unit, and method of controlling head unload
US6141173A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 1998 |
| Grant date | Oct 31, 2000 |
| Priority date | — |
| Expiry date | Jun 10, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B21/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention is an apparatus and method to reliably unload a head slider from a recording medium. Transistor Tr5 is on. If the main power supply Vdd is turned off at time t1, Tr1, Tr2, and D1 are turned off and the level of the control signal Ret becomes higher than the threshold voltage Vth of Tr3 and Tr4, turning on Tr3 and Tr4. C1 also starts to discharge. The control signal InRet changes to a "L"-level, and the control signal OutRet remains to be at the "L"-level. This allows the IR driver to feed a negative-polarity VCM current through the voice coil to preliminarily move the head arm in the direction opposite to the unload direction. Then, at time t2 when the level of Ret becomes equal to or lower than Vth, both InRet and OutRet change to a "H"-level, the IR driver becomes inoperative, and the OR driver feeds a positive-polarity VCM current through the voice coil to reverse the moving direction of the head arm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.