Lens system for deflected light beam
US4712884A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 1986 |
| Grant date | Dec 15, 1987 |
| Priority date | — |
| Expiry date | Jan 27, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B13/0005
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A lens system for use in a light beam scanner for deflecting a monochromatic or quasi-monochromatic light beam, the lens system being disposed between a deflection point about which the light beam is deflected and a surface to be scanned in the light beam scanner. The lens system comprises an f.theta. lens and a corrective lens. The f.theta. lens comprises two positive-meniscus lenses with their concave surfaces directed toward the deflection point, the f.theta. lens having an effective deflection angle of at least 50 degrees. The corrective lens cooperates with the f.theta. lens in constituting a surface irregularity correcting optical system and is disposed between the f.theta. lens and the surface to be scanned. The corrective lens comprises a toroidal lens capable of correcting surface irregularity and curvature of field.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.