Scanning lens and scanning apparatus using scanning lens
US5128795A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 1990 |
| Grant date | Jul 7, 1992 |
| Priority date | — |
| Expiry date | Aug 10, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/1135
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A scanning apparatus comprises a light source for emitting a light along an optical axis, a focusing lens for converting the light emitted from the light source into a convergent light, a deflector for deflecting the convergent light from the focusing lens so that a deflected light is scanned at a substantially uniform angular velocity on an image surface, the deflector having a deflection surface on which the convergent light is deflected, and a scanning lens for focusing the deflected light from the deflector so that a focused light is scanned on the image surface in a main scanning direction to form scanning spots thereon at a substantially uniform scanning rate, the scanning lens being made of a material with a refractive index n and constructed as a single lens having a focal length f. The scanning lens according to the present invention provides a well corrected curvature of field in the main scanning direction and at the same time a good scanning linearity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.