Light beam scanning apparatus and image forming apparatus
US6411321B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 1998 |
| Grant date | Jun 25, 2002 |
| Priority date | — |
| Expiry date | Sep 10, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4005
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a digital copying machine using a multi-beam optical system, a sensor pattern SH for sensing the power of each of the light beams a to d scanning the surface of a photosensitive drum and sensor patterns SB1 to SF1, SB2 to SF2 for sensing the passing positions of the beams are provided in a light beam position sensing unit. The sensor patterns SB1 to SF1, SB2 to SF2 are arranged linearly in the sub-scanning direction at intervals corresponding to two resolutions. The power of each light beam on the surface to be scanned is controlled so as to be in a specific range. Even when the light beams are scanned with different resolutions, they can be controlled with high accuracy so as to constantly have an ideal positional relationship between them. This always assures high picture quality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.