Apparatus for selective retrieval of information streams or items
US4321635A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 20, 1979 |
| Grant date | Mar 23, 1982 |
| Priority date | — |
| Expiry date | Apr 20, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/90
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A video disc player for use with a record disc having recorded along a spiral track thereon a succession of information streams to be reproduced and a series of addresses identifying the successive turns of the track. Also recorded on the record disc, prior to the information streams, is an index listing at least the starting addresses of the information streams. An optical pickup assembly reads the record disc by traveling in its radial direction in step with the rotation of the disc. A memory stores the index read from the record disc and, upon actuation of one of information selector switches by the operator, delivers the starting address of the selected information stream to a comparator circuit. During the subsequent process of access to the selected information stream, perhaps with the pickup assembly fed at high speed toward same, the comparator circuit receives another input representing that address on the record disc which corresponds to the position of the pickup assembly relative to the disc. Upon agreement of the two inputs the comparator circuit produces an output for stopping the radial motion of the pickup assembly or for switching its radial motion from high to nor…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.