Scanning optical apparatus having focus position detector
US4990771A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1990 |
| Grant date | Feb 5, 1991 |
| Priority date | — |
| Expiry date | May 11, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B26/10
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A scanning optical apparatus comprises a light source unit, an optical system for converging a light beam from the light source unit at a predetermined position, a moving device for moving the converged position of the light beam by the optical system, a deflecting device for deflecting the light beam from the light source unit in a predetermined direction, a light receiving device for receiving the light beam deflected by the deflecting device, a processing device for processing a signal obtained by said light receiving device, and a control device for controlling the moving device corresponding to a signal from the processing device. The light beam emitted from the light source unit is scanned on the light receiving device a plurality of times through the optical system and the deflecting device, while the converged position of the light beam is moved by the moving device. The signal from the light receiving device during each of the plurality of scans is compared or calculated by the processing device to thereby adjust and determine the converged position of the light beam by the optical system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.