Shock resistant winchester disk drive
US4947093A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 25, 1988 |
| Grant date | Aug 7, 1990 |
| Priority date | — |
| Expiry date | Nov 25, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/5582
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A shock resistant hard disk drive system employs a plurality of magnetic disks for recording data, a plurality of magnetic heads for performing input/output operation on the magnetic disks, with at least one of the magnetic heads being used as a servo head, a head-positioning mechanism for controlling the movement of the magnetic heads, a servo control mechanism or servo loop for opposing shifts in the location of the servo head, detecting device for detecting and measuring certain accelerations applied to the system, and filtering device for filtering the output of said detecting device and for providing the signal to the head-positioning mechanism. The detecting device detects and measures the magnitude of internal or external accelerations or shocks applied to the system, and provides the necessary signals to counter such accelerations. The pre-existing phase locked loop includes a voltage controlled oscillator, with the voltage control signal applied to the oscillator indicating instantaneous rotational velocity resulting from accelerations applied to the system; and this control signal is modified and applied to servo loop for the head positioner, to hold the head positioner a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.