Method and apparatus for calibrating a linear array scanning system
US4408231A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 1981 |
| Grant date | Oct 4, 1983 |
| Priority date | — |
| Expiry date | Jul 31, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/40056
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A linear image sensor and the video channel associated with the sensor are calibrated to maximize the video signal available. The sensor is limited in output by saturation of the CCD analog shift registers in the sensor. The channel is limited by the range of the analog-to-digital converter in the channel. The useable video signal is maximized by calibrating the sensor relative to its saturation condition and by adjusting the gain of the video channel relative to the range of the analog-to-digital converter. The sensor is calibrated by adjusting its exposure to illumination. The adjustment may be made by adjusting the illumination source or by changing the sampling interval for the sensor. The gain is adjusted by using a variable gain amplifier. A microprocessor monitors the digitized video signal and controls the exposure and gain to calibrate the sensor and channel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.