Method and apparatus for retracting head and braking motor of a disc drive device
US4658308A · kind A · utility
48Cited by
5References
16Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 5, 1986 |
| Grant date | Apr 14, 1987 |
| Priority date | — |
| Expiry date | Mar 5, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/54
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The head assembly of a disc drive device is retracted upon the interruption of power to that device by utilizing the emf that is generated by the disc drive spindle motor as a result of the rotation of that motor following power interruption. Then, after a delay sufficient to allow the head assembly time to retract, the spindle motor is dynamically braked. Dynamic braking is achieved by utilizing a voltage to which a capacitor has been charged during normal operation to energize switching elements which effectively short circuit the motor windings.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.