Imaging array having variable conversion gain
US7268338B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 6, 2005 |
| Grant date | Sep 11, 2007 |
| Priority date | — |
| Expiry date | Aug 12, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/78
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A CCD imaging array and a charge measurement amplifier for use in such imaging arrays is disclosed. The array includes a plurality of pixels that accumulate charge when exposed to light, a readout amplifier having input and output ports. The readout amplifier has a variable gain that is set by a gain control signal. The readout amplifier also includes a reset path between the input and output ports, the path having an impedance controlled by a reset signal. A controller generates the gain control signal and the reset signal during a charge measurement cycle. Initially the gain is set to a first value after generating the reset signal. The gain is changed to a second value during the charge measurement cycle if the output signal exceeds a first threshold value. The readout amplifier can be constructed from an operational amplifier having a capacitive feedback loop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.