A digital X-ray image sensor device comprising a fibre-optic scintillating layer for converting X-rays into optical radiation and a photoelectric conversion layer for converting the optical radiation into electrical signals, the photoelectric conversion layer comprising an array of CMOS sensor elements, wherein each of the sensor elements has a composite exposure response characteristic comprising a low exposure region characterized by a first gain and a high exposure region characterized by a second gain, wherein the first gain is higher than the second gain.
DIGITAL X-RAY IMAGE SENSOR DRIVE