Semiconductor laser driving circuit
US5163063A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Feb 4, 1991 |
| Grant date | Nov 10, 1992 |
| Priority date | — |
| Expiry date | Feb 4, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/06835
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A semiconductor laser driving circuit has a semiconductor laser for emitting a laser beam according to a drive power. A photodetector is provided for effecting photo-electric conversion of the laser beam to output a corresponding electric signal. A monitoring circuit is connected for monitoring the electric signal to output a monitor signal indicative of variation in intensity of the laser beam. A controlling circuit is connected for comparing the monitor signal with a given reference signal to output a control signal according to difference therebetween. A powering circuit is operative according to the control signal to apply to the semiconductor laser a drive power effective to eliminate the difference. An abnormality detecting circuit is provided for comparing the monitor signal with a given limit signal which is set different from the reference signal to detect abnormality to output an abnormality signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.