Semiconductor laser control circuit
US4856011A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 1988 |
| Grant date | Aug 8, 1989 |
| Priority date | — |
| Expiry date | Nov 8, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/0427
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A system for controlling the operation of a semiconductor laser is provided. In one aspect of the present invention, a switching element, which is turned on and off in accordance with a signal modulated with image information, is connected in series with the semiconductor laser for controlling the operation thereof. In another aspect of the present invention, a semiconductor laser control system includes a photodetector for detecting the intensity of a laser beam emitted from the laser, a comparator for comparing the detected intensity with a predetermined refence intensity, an up/down counter which changes its count depending on the result of the comparison at the comparator, and a laser driver which supplies a driving current to the laser as modified by the count of the counter. A reset circuit is provided to reset the counter when at least the laser driver is powered up with a predetermined supply voltage. In addition, the laser driver is so structured that the supply of the driving current to the laser is disconnected for a predetermined time period after the power up thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.