Synchronizing signal generating system for laser scanner
US4962431A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 1989 |
| Grant date | Oct 9, 1990 |
| Priority date | — |
| Expiry date | Feb 17, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/04798
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A synchronizing signal generating system for a laser scanner includes a source for emitting a first laser beam for scanning and a second laser beam for synchronization of scans by the first laser beam, a polygonal mirror for causing the first laser beam to scan a medium and for causing the second laser beam to scan a grating which has bright portions and dark portions alternately arranged along a scanning direction of the second laser beam, a converging optical system for converging the second laser beam transmitted through the grating, a light receiving system for receiving the second laser beam converged by the converting optical system and for generating a synchronizing signal and a circuit for controlling the source responsive to the synchronizing signal so as to synchronize a scan timing of the first laser beam. A scan length of the second laser beam measured on the grating is set longer than a scan length of the first laser beam measured on the same plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.