Image sensor
US7566876B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 2006 |
| Grant date | Jul 28, 2009 |
| Priority date | — |
| Expiry date | Nov 30, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/191
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Effective sensitivity of a photodetector of an image sensor is controlled by partitioning signal charge from incident photons, thus producing a manageable yield and a consequently higher, photon shot noise limited, signal to noise ratio than in the prior art, when imaging high flux rates of energetic photons or particles, such as produced by x-ray generators. The invention may be applied, for example, to an image sensor with a photosensitive layer coupled to a charge collection/readout structure, e.g. photoconductor or scintillator on CMOS array, or to an intrinsically sensitive charge collection/readout structure, e.g. deep active layer CMOS. A radiation sensor pixel structure 10 for use in the invention includes a photodetector 11, a transfer gate 131 for controlling charge collection from the photodetector and a dump drain 12 controlled by a dump gate 121, arranged for selectively dumping charge to the dump drain means and collecting charge from the photodetector means, in a duty cycle 31, for varying effective sensitivity of the pixel structure. An image sensor containing such pixel structures may selectively be operated in an integration mode or a photon counting mode. Prefera…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.