Light beam scanning apparatus
US6462855B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 2000 |
| Grant date | Oct 8, 2002 |
| Priority date | — |
| Expiry date | Sep 30, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/04794
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A pair of sensor patterns detect a passage position in a sub-scan direction of a light beam scanned over a surface of a photosensitive drum. The sensor patterns have, for example, trapezoidal shapes and are disposed symmetrical at a position equivalent to a position of the surface to be scanned. The sensor patterns are juxtaposed in a scan direction of the light beam at a predetermined interval therebetween. An output integration value from one of the paired photodetector elements successively increases while an output integration value from the other photodetector element successively decreases in relation to a variation of a passage position of the light beam in the sub-scan direction. On the basis of a difference between the output integration values of the paired sensor patterns, the passage position of the light beam in the sub-scan direction is detected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.