Target track position retrieval device
US5216647A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 18, 1990 |
| Grant date | Jun 1, 1993 |
| Priority date | — |
| Expiry date | Dec 18, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B21/083
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
This invention is directed to a target track retrieval device comprising a signal playback apparatus for playing back signals from information tracks recorded on a rotary disc rotatably driven at constant linear velocity, a movement circuit for moving the playback apparatus in a direction traversing the information tracks, a counter responsive to the signals from the playback apparatus to count the number of information tracks traversed by the playback apparatus, and a control circuit for comparing target position information indicating a target track position and a count value of the counter to stop movement of the playback apparatus when the target position information and the count value are in correspondence with each other. The number of tracks [M] from a present track position to the target track is determined as a function of the number of tracks [n] to be traversed by the playback apparatus during a playback time [t.sub.n ] from a reference track to the target track, in accordance with: ##EQU1## where [v.sub.o ] is the linear velocity, [p] is the track pitch and [r.sub.o ] is the radius of the reference track; and the rotational velocity of the rotary disc when the target t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.