Color scanner using both variable led exposure time and photo detector output compensation
US5729361A · kind A · utility
17Cited by
10References
32Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1995 |
| Grant date | Mar 17, 1998 |
| Priority date | — |
| Expiry date | Jun 30, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/484
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention provides a combination of first providing a coarse adjustment by varying the emitter power and duration of the emitter/detector exposure time, and then providing a fine adjustment by storing a correction value for each photodetector element. The adjustment for each photodetector corrects not only for the range, but also for the offset, providing two correction values. In a preferred embodiment, the low and high voltage reference levels for an analog to digital converter are adjusted and stored for each photodetector for each color.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.