Scanning optical system for use in a laser beam printer
US4953926A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 13, 1989 |
| Grant date | Sep 4, 1990 |
| Priority date | — |
| Expiry date | Mar 13, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/0031
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical scanning system for use in a laser beam printer is disclosed which comprises a cylindrical lens for imaging laser light in an auxiliary scanning cross section at a point in front of a deflector and an anamorphic scanning lens unit which converges the light rays deflected by the deflector at a point on a scanning surface. The scanning lens unit has, in order from the deflector side, a first lens which is a negative lens element having a concave toric surface with a stronger curvature in the auxiliary scanning cross section and a second lens having a convex toric surface with a stronger curvature in the auxiliary scanning cross section. The optical system further satisfying the following condition: EQU 0.015f<l<0.160f where f is the focal length of the scanning lens unit in a main scanning cross section, and l is the distance between the position at which laser light is imaged with the cylindrical lens and the point at which the laser light is deflected with the deflector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.