LARGE-AREA AMORPHOUS-SILICON X-RAY IMAGERS

Large two dimensional amorphous silicon imaging arrays are of interest for electronic document input and x-ray imaging. The device is a matr ix-addressed array of light detectors fabricated from hydrogenated amo rphous silicon on a glass substrate. Each imaging pixel consists of a light sensor and a thin film transistor (TFT). X-ray imaging is accomp lished by placing a phosphor in contact with the image sensing surface , or by direct detection with a thick photoconductor. The imager techn ology is now capable of 10 in. arrays with image capture at greater th an 10 frames/sec and with resolution of 4-6 1p/mm. We describe our new high resolution imaging system, comprising the sensor array with an a ctive area of approximately 8 x 10 in. having nearly 3 million pixels, and the accompanying readout electronics. Key technological issues an d alternative array designs are discussed.