Image scanner with automatic signal compensation
US6522432B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 16, 1996 |
| Grant date | Feb 18, 2003 |
| Priority date | — |
| Expiry date | Mar 1, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4076
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to an image scanner with automatic signal compensation function for compensating the instability of a light source of the image scanner. The image scanner comprises a test region, a light source for illuminating the document and the test region, optical means for conveying the light reflected from the document and the test region, a line image sensor for receiving the light from the optical means and generating an image signal corresponding to the light reflected from the document and a brightness signal corresponding to the light reflected from the test region, and a signal compensation circuit for amplifying the image signal according to the brightness signal to compensate the instability in the brightness of the light source.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.