Amorphous selenium flat-panel detection technology -- direct imaging technology:
It is composed of amorphous selenium layer and TFT(Thin Film Transistor).
The amorphous selenium layer absorbs the incident X-ray radiation and coverts it to electron-hole pairs, which are separated by the applied electric field to opposite direction. Charges are collected by the pixel storage and the quantity represents the signal is read out by switching TFT at that pixel. Digital signals read out from a large size of pixel array form the X-ray image.
Direct converting technology iminated visible light conversion produces high a resolution image.