Optical scanner and image forming apparatus
US8253994B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 14, 2008 |
| Grant date | Aug 28, 2012 |
| Priority date | — |
| Expiry date | Jun 26, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/02495
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image forming optical equipment is disposed between a polygon mirror and the surface of a photoreceptor drum to form an image on the surface of the photoreceptor drum with scanning light, while at the same time, keeping its scanning speed nearly-constant, comprises a first scanning light lens, which has a positive power in the main scanning direction and a negative power in the sub-scanning direction, a second scanning light lens, which has a negative power in the main scanning direction and a positive power in the sub-scanning direction and is disposed in the side closer to the photoreceptor drum than the first scanning light lens, and a diffraction optical element, which is provided on the surface of the cylindrical lens in the beam light advancing path between a light source and a polygon mirror.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.