Optical disc recording and retrieval system
US4433403A · kind A · utility
5Cited by
5References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1981 |
| Grant date | Feb 21, 1984 |
| Priority date | — |
| Expiry date | Apr 15, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B27/30
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical signal recording and reproduction or retrieval system which records a primary signal on a recording track provided on a recording medium by projecting a laser beam which has been modulated by the primary signal onto the recording track, and further records a secondary signal, by superposition, on the recording track by projecting the laser beam which has been modulated by the secondary signal having a frequency band which is different from that of the primary signal onto the recording track for enabling the deleting of the previously recorded primary signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.