Scanning image forming lens and optical scanning apparatus
US6130768A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 11, 1998 |
| Grant date | Oct 10, 2000 |
| Priority date | — |
| Expiry date | Aug 11, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B26/125
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A scanning image forming lens in an optical scanning apparatus for optically scanning a surface to be scanned at a constant velocity by deflecting a luminous flux formed as a linear image in a direction corresponding to a main scanning direction by an optical deflector having a deflecting reflective plane in the vicinity of the linear image so as to collect the deflected luminous flux on the surface to be scanned as a light spot with a scanning image forming lens, includes two lenses. The first lens provided at the optical deflector side is a positive meniscus lens with a concave surface facing toward the optical deflector side and has a co-axial aspherical shape at both sides. The second lens provided at the surface to be scanned side is symmetrical relative to an optical axis thereof and has a non-arc shape in the deflected plane at least at one surface, and the non-arc surface is shaped such that the radius of curvature in the sub scanning cross-section changes in the direction corresponding to the main scanning direction in a manner such that the curvature center line plotting the curvature center in the sub scanning cross-section of the lens surface in the direction correspond…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.