Image sensor utilizing a low FPN high gain capacitive transimpedance amplifier
US6459078B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 4, 2000 |
| Grant date | Oct 1, 2002 |
| Priority date | — |
| Expiry date | Apr 17, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/677
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An imaging element and an imaging array constructed from such elements. The preferred imaging element is constructed from a photodiode having a parasitic capacitance Cpd; and an amplifier for measuring the charge stored on the parasitic capacitor. The amplifier includes an opamp having a signal input, reference input and output; the first terminal of the parasitic capacitor is connected to the signal input. The imaging element includes a reset switch for shorting the signal input and the output of the opamp, and capacitive network. The capacitive network connects the signal input and the output of the opamp, and provides a capacitance of CT between the signal input and the output of the opamp wherein CT<Cpd. The capacitive network is constructed from a plurality of component capacitors. Preferably each component capacitor has a capacitance greater than or equal to Cpd. An imaging array according to the invention includes a plurality of imaging elements, a signal bus, a reset bus, and a reset circuit. Each imaging element also includes a coupling switch for connecting the output of the opamp to the signal bus and a reset coupling switch for connecting the photodiode to the reset bus…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.