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.

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.

Abstract: An X-ray examination apparatus and method that provides fast and accurate control of the X-ray dose by combining a fast and inaccurate sensor dose signal for an X-ray sensor and a slow and accurate detector dose signal from an X-ray detector. The combination of the signals takes into account the delay between the two signals so that they are measured at essentially the same time.