Image sensor apparatus with noise cancellation circuitry
US5231503A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 26, 1991 |
| Grant date | Jul 27, 1993 |
| Priority date | — |
| Expiry date | Jul 26, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/63
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image sensor apparatus includes a matrix array of optical/electrical conversion elements, switching elements for taking out electric charge stored on the conversion elements, and drive circuits for driving the switching elements thereby to take out image signals from the conversion elements in parallel. A matrix array of noise signal retaining circuits is provided on output sides of the conversion elements for temporarily retaining in parallel, as noise signals, signals produced while the optical/electrical conversion elements are not being driven. Subtracting circuits are provided for subtracting from the parallel image signals in parallel the noise signals retained in the noise signal retaining circuits. A multiplexer converts the parallel output signals from the subtracting circuits into a serial signal in a predetermined sequence. Thus, the image sensor apparatus temporarily retains in parallel the parallel noise signals produced as a result of fluctuations in the characteristics of circuit elements, and cancels out with the subtracting circuits substantially the same noise which is contained in the image signals output from the conversion elements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.