Laser driving device provided with two reference signal sources, and optical information recording apparatus using the same device
US4967417A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 10, 1989 |
| Grant date | Oct 30, 1990 |
| Priority date | — |
| Expiry date | Jul 10, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/06213
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A laser driving device is disclosed. The laser driving device includes a semiconductor laser, a current source for supplying an electric current to the semiconductor laser, a photodetector for monitoring light emitted from the semiconductor laser, a plurality of setting circuits for outputting reference signals of different levels, a switching circuit for selecting one of the outputs of the setting circuits, a comparing circuit for comparing the output selected by the switching circuit with the output of the photodetector, and a control circuit for controlling the electric current supplied to the semiconductor laser on the basis of the output of the comparing circuit so that the two outputs become equal to each other. Also disclosed is an optical information recording apparatus using such a laser driving device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.