Process for searching for a track on a rotating plate-like information support and circuit for performing the process
US4847821A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 24, 1987 |
| Grant date | Jul 11, 1989 |
| Priority date | — |
| Expiry date | Aug 24, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B21/083
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A writing and/or reading head can write and/or read data on the tracks of an information support. The writing and/or reading head can be positioned over each track of the information support by means of a coarse-feed drive (S, G) and by a fine-feed drive (S, F) which is mechanically linked with the coarse-feed drive. When searching for a track, the coarse-feed drive travels fast over the tracks until it stops at the target track. The braking phase of the coarse-feed drive is kept short by a large time-log. At the latest at the beginning of the braking phase of the coarse-feed drive the regulating circuit of the fine-feed drive is disconnected. During the braking phase a control signal is applied to the fine-feed drive which clamps the mechanical oscillations of the fine-feed drive as a result of the inertial forces which arise when the coarse-feed drive is braked. Consequently, after braking of the coarse-feed drive, the regulating circuit of the fine-feed drive can again be connected. The fine-feed drive is then brought precisely over the track sought.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.