Light intensity controlling device
US5892219A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 1996 |
| Grant date | Apr 6, 1999 |
| Priority date | — |
| Expiry date | May 29, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/4025
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A light intensity controlling device has a beam splitter which splits light fluxes emitted from a plurality of independently controlled semiconductor lasers, guided by optical fibers, into monitor light fluxes and main light fluxes. A gain adjusting circuit corrects the changes of output of light receiving elements depending on the polarization states of the light fluxes incident into the beam splitter. The changes result from the polarization characteristics of the optical fibers and/or the beam splitter. Alternatively, a filter is provided at one of the light receiving elements to compensate for the changes, thus providing a corrected output signal. Laser control circuits control the light emitting intensity of each semiconductor laser based on corrected output signals. The light receiving elements are set at an angle to the incoming light as so to avoid directing reflected light back toward an imaging system or the lasers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.