Method for controlling laser light power, method for data recording into optical disc, and optical disc recording apparatus
US6407976B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 3, 1998 |
| Grant date | Jun 18, 2002 |
| Priority date | — |
| Expiry date | Apr 3, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/00454
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A laser light power controlling method is provided which comprises the steps of irradiating onto an optical disc a laser light generated by a laser source driven under a data write signal; detecting a reflected portion of the laser light irradiated onto the optical disc; and detecting an undershoot of a detection signal of the reflected laser light and controlling the power of the laser light in accordance with the amount of the detected undershoot. Also, a method for writing data into an optical disc is provided which comprises the steps of irradiating onto an optical disc a laser light generated by a laser source driven under a data write signal; detecting a reflected portion of the laser light irradiated onto the optical disc; and detecting an undershoot of a detection signal of the reflected laser light and discriminating the level of the undershoot with reference to a predetermined threshold. Further, an optical disc recording apparatus is provided which comprises means of irradiating a laser light onto an optical disc correspondingly to a data write signal; a photodetector to detect a reflected portion of the laser light irradiated onto the optical disc; and an undershoot det…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.