High dynamic range X-ray detector with improved signal to noise ratio
US8546765B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 2009 |
| Grant date | Oct 1, 2013 |
| Priority date | — |
| Expiry date | Jul 7, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/771
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An x-ray detector and its pixel circuit are described, that allow to cover a large dynamic range with automatic selection of the sensitivity setting in each pixel, thus providing improved signal to noise ratio with all exposure levels. X-ray detectors are required to cover a large dynamic range. The largest exposure determines the required pixel capacitance. However, a large pixel capacitance gives a bad signal to noise ratio with small exposures e.g. in the dark parts of the image. This invention disclosure describes several approaches to provide automatic sensitivity selection in the pixels. This ensures that low signals are stored in a small capacitor or read out with a high sensitivity with corresponding good signal to noise ratio, while larger signals are stored in larger capacitors or are read out with lower sensitivity so that no information is lost.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.