Afocal optical system for focus error correction in laser scanning systems
US5257125A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 27, 1991 |
| Grant date | Oct 26, 1993 |
| Priority date | — |
| Expiry date | Nov 27, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/0031
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A raster scanning system is disclosed which utilizes a focus error correction system and a pre-polygon cross-scan cylindrical lens for correcting focus error both in the fast-scan plane and in the cross-scan plane without affecting the scan characteristics of the post polygon optics. The focus error correction system comprises at least two lenses which can be either spherical or fast-scan cylindrical lenses and one of the lenses must be axially adjustable. By adjusting the adjustable lens, a positive or a negative optical power can be added to a beam passing through the focus error correction system in order to correct the focus error in the fast-scan plane. The pre-polygon cross-scan cylindrical lens is also adjustable to correct the focus error in the cross-scan plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.