Method and apparatus for calibrating the writing power applied to an optical media
US5050156A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 25, 1989 |
| Grant date | Sep 17, 1991 |
| Priority date | — |
| Expiry date | Oct 25, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B27/36
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention automatically performs a series of measurements on an optical media based on writing a power ramp signal of known power levels (amplitudes) on a target sector of the optical media. The amplitudes of the written power levels are measured. A comparison of the measured amplitude of each level of the recorded power ramp signal against reference amplitudes is made to establish a matching factor. The power level having the closest matching factor is selected as the power level to be used for the best recording of data onto the optical media. The procedure may be iterated a number of times to form an average that can then be used as the write power level. The present method also provides a pre-emphasis calibration by writing a pre-emphasis ramp in a target sector which is compared against a desired duty cycle to select the pre-emphasis which yields the desired duty cycle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.