Multi-beam scanning optical system and image forming apparatus using it
US6667820B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 23, 2002 |
| Grant date | Dec 23, 2003 |
| Priority date | — |
| Expiry date | Sep 23, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/04786
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Provided are a multi-beam scanning optical system capable of implementing high-quality printing in relatively simple structure and at high speed, and an image forming apparatus using it. The multi-beam scanning optical system has an incidence optical unit for guiding a plurality of beams emitted from a light source unit having a plurality of light-emitting regions spaced apart from each other in a main scanning direction, to a deflector; a scanning optical unit for focusing the plurality of beams deflected by the deflector, on a surface to be scanned; and a synchronism-detecting optical unit for converging part of the plurality of beams deflected by the deflector, via a return mirror on a slit surface by a lens section, thereafter guiding the beams to a synchronism detector, and controlling timing of a scan start position on the surface to be scanned, by use of a signal from the synchronism detector. The elements are set so as to satisfy Condition (A) where &dgr;M is a defocus amount in a main scanning section of the beams guided to the synchronism detector and in a view from the slit surface and &dgr;X is a defocus amount at each image height on the surface to be scanned.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.