Light beam scanning apparatus for use with image forming apparatus
US5995246A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1997 |
| Grant date | Nov 30, 1999 |
| Priority date | — |
| Expiry date | Jun 2, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/04791
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a digital copying mechine using a multi-beam optical system, first light receiving elements of a light beam detector placed on the extension of the surface of a photosensitive drum detects the positions of paths of scanning light beams in the sub-scanning direction. On the basis of the results of this detection, the amount of control for the position of the path of each light beam is calculated. Galvano mirrors, adapted to reflect the light beams onto the surface of the photosensitive drum, are driven accordingly, so that the paths of the light beams are properly positioned in the sub-scanning direction. Second light receiving elements of the light beam detector detect times at which the light beams move across the light beam detector. A sync clock is produced after a delay from when each light beam moves across the light beam detector. The spacing between each second light receiving element is set to an integral multiple of the length of one dot formed by a light beam on the photosensitive drum in the main scanning direction. In synchronism with the sync clocks, pixel clocks and image data are applied to laser oscillators to form an image on the surface of the photosensitive dr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.