Extended correlated double sampling for charge transfer devices
US4035629A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1975 |
| Grant date | Jul 12, 1977 |
| Priority date | — |
| Expiry date | Oct 24, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/891
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Extended correlated double sampling (ECDS) for charge transfer devices (CTD) corrects for errors arising in components of the CTD system from the input to the output thereof. Sources of error include bias variations and non-uniformity of thresholds and leakage currents. While applicable to any type of CTD system, for a TDI (time delay integration) application, precise error correction is achieved. Alternate signal level samples and reference level samples, the latter preferably AC zero, are propagated down the CTD channel as a related pair. At the CTD output, the signal and reference level samples of each pair are differenced, thereby correcting the resultant output signal for the noted types of errors. ECDS is compatible with CDS as taught in U.S. Pat. No. 3,781,574 and the two may be used jointly. An application of ECDS in the TDI mode for enhancement of signal outputs from a sensor array is disclosed, along with special parallel signal injection structure and operation for the requisite parallel signal injection into the channel, and special techniques of stabilized charged injection (SCI).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.