Imaging assembly for imaging radiation

摘要

A semiconductor radiation imaging assembly comprises a semiconductor imaging device including at least one image element detector which receives a bias for forming the element detector and bias monitoring means (20) for monitoring the bias to determine radiation incident on the image element detector. Preferably there are a plurality of detectors and the bias of all of the detectors is monitored to produce a trigger signal when the bias current or a derivative thereof transgresses a threshold. An X-ray image of part of the human body may be formed on a 2D array of detectors. The trigger signal may cause an image frame forming a single exposure to be stored. A derivative of the bias current may be formed by differentiating and/or integrating the current using high and low pass filters (124, 126) and fed to a threshold comparator (132). A quiescent bias value may be stored and subtracted from the exposure bias value.