Readout circuit for an optical sensing charge injection device facilitating an extended dynamic range
US4734776A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 1986 |
| Grant date | Mar 29, 1988 |
| Priority date | — |
| Expiry date | Aug 15, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/76
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention relates to a charge injection device for optical sensing including a novel readout circuit facilitating an extended dynamic range. The invention has primary application to linear arrays for IR sensing. Sensitive, low-level operation is achieved in a primary readout means by allowing the charge to accumulate in the potential well of the individual sensor elements over the line period with each element being reset at the pixel readout rate and by using a charge injection pulse to clear stored charge from the individual sensor elements. A secondary readout means is also provided in which the charge is allowed to accumulate over a period not exceeding the pixel readout interval for unsaturated large signal operation and by sensing the change in depth of the potential well. The two readout means are combined in the eventual display to provide an improvement of typically three orders of magnitude in the dynamic range of the CID.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.