Flat panel detector and image sensor with means for columating and focusing electron beams

A flat panel image sensor is provided by combining the photoconductive imaging electrode of a vidicon with a two dimensional array of cold cathode field emitters commonly used for flat panel Field Emission Display (FED) systems. The FED operates normally to emit electrons which are accelerated in prior art displays towards a luminescent phosphor to generate light output proportional to the cathode emission. Rather than accelerating towards a phosphor, electrons, in accordance with the principles of this invention, are accelerated towards a photoconductor layer to replace charge removed from the layer by an incident radiation pattern directed at the photoconductor layer through a layer of transparant, electrically-conducting material which serves as a radiation window. A large area, low cost, small, flat panel sensor is realized. The transparant, electrically-conducting layer may be partitioned to reduce stray capacitance for large area sensors and the partitioned, electrically-conducting layer permits a parallel readout mode of operation. The sensor includes a means for collimating and focusing the electron beams and may be used with infra red and ultra violet photoconductor materials.