Charge amplifier for MOS imaging array
US6351283B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 27, 1996 |
| Grant date | Feb 26, 2002 |
| Priority date | — |
| Expiry date | Nov 27, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/78
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An improved charge amplifier (105) for use in a MOS imaging array is disclosed. The charge amplifier comprises a reference capacitor (Cr), a sense capacitor (Cs), an operational amplifier (107), a first output capacitor (Co1) connected to the output of the operational amplifier, a second output capacitor (Co2) connected to the output of the operational amplifier, and a differential amplifier (109) connected to the first output capacitor and said second output capacitor. In operation, the reference capacitor is charged to a reference voltage. Similarly, the sense capacitor is charged to a reference voltage. Both the sense capacitor and the reference capacitor are formed to be identical. However, the reference capacitor is covered from ambient light and the sense capacitor is exposed to ambient light. As ambient light is incident on the sense capacitor, the voltage carried by the sense capacitor diminishes. After a predetermined exposure time, both the voltage stored across the reference capacitor and the sense capacitor is amplified by the operational amplifier. Next, the differential amplifier operates to provide an output signal that is the difference between said amplified versio…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.