Optical scanning apparatus with controlled sag and ghost
US6104522A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 1997 |
| Grant date | Aug 15, 2000 |
| Priority date | — |
| Expiry date | Sep 11, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B26/125
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical scanning apparatus includes a light source, a first optical system which includes a coupling lens for coupling a beam from the light source, a polygon mirror for deflecting the beam from the first optical system at a constant angular velocity, and a second optical system which includes a scanning and imaging element for converging the deflected beam on a scanned surface so as to scan the scanned surface substantially at a constant velocity, wherein following conditions are satisfied EQU .THETA./2<.alpha.<(4.pi./N)-(.THETA./2) (1) EQU R.multidot.sin(.alpha./2).multidot.1.03<h<R.multidot.sin(.alpha./2).multido t.1.1 (2) where N indicates the number of deflecting and reflecting surfaces of the polygon mirror, R indicates a radius of an inscribed circle in the deflecting and reflecting surface, .alpha. indicates an angle formed by a chief ray of the deflected beam so as to be perpendicular to the scanned surface and an optical axis of the first optical system, .THETA. indicates an angular field of view that corresponds to an effective write width on the scanned surface and h indicates a distance between a center of rotation of the polygon mirror and the optical axis of the f…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.