Calibration device of the optical power applied to an optical disc for recording of data
US4631713A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 17, 1984 |
| Grant date | Dec 23, 1986 |
| Priority date | — |
| Expiry date | May 17, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B27/36
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The device according to the invention realize the following steps: PA1 (a) recording of binary test words on an optical disc associated to distinct engraving optical powers and comprising monotonous series of "1" and "0" logic bits of equal duration; PA1 (b) reading of these words; PA1 (c) measurement of the durations of these bits in the "1" state and bits in the "0" state, PA1 (d) determination of the optical power for which this ratio is closest to one; PA1 (d) elaboration and putting in memory of a control signal allowing to obtain this power. In a preferred variant, several test words are recorded and an interpolation is carried out between the measurements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.