REAL TIME, LIGHT WEIGHT X-RAY IMAGER

A COMPACT, LIGHT WEIGHT, LARGE AREA, HIGH RESOLUTION TWO-DIMENSIONAL REAL-TIME DIGITAL X-RAY IMAGING SYSTEM, BASED ON THE DEVELOPMENT OF AN INTEGRATED A-SI:H PHOTODIODE ARRAY AS IMAGE SENSOR IS PROPOSED. THE FIRST PROTOTYPE IMAGE SENSOR WILL HAVE A SENSITIVE AREA 8" X 10" WITH 1024 X 1280 PIXELS COUPLED TO AN OPTIMIZED SCINTILLATOR SUCH AS GD2O2S:TB AS AN X-RAY CONVERTER. EACH DIODE ELEMENT IS CONNECTED THROUGH A INTEGRATED POLY-SILICON NMOS THIN FILM TRANSISTOR TO A COLUNM AND A ROW ANALOG SHIFT REGISTERS WHICH IS CONTROLLED BY 13 MHZ CLOCK PULSES. THE INTEGRATION TIME IS CONTROLLABLE THROUGH A COMPUTER. WITH A DATA TRANSFER TIME 0.1 SEC/FRAME, AND WITH A DISPLAY TIME LESS THAN 1 SEC., THE OUTPUT DATA IS FURTHER DIGITIZED BY A FRAME GRABBER SUD DISPLAYED OR FURTHER PROCESSED BY COMPUTER. THE DIGITAL IMAGE SYSTEM HAS A SENSITIVE AREA AND A IMAGE RESOLUTION COMPARABLE TO THE TRADITIONAL SCREEN FILM COMBINATION; THE SYSTEM CAN HAVE A MUCH HIGHER SENSITIVITY AND DYNAMIC RANGE THAN THE EXISTING SCREEN FILM COMBINATION.