摘要 |
<p>ELECTROSTATIC X-RAY IMAGE RECORDING DEVICE WITH MESH-BASE PHOTOCATHODE PHOTOELECTRON DISCRIMINATION MEANS An electrostatic X-ray image recording device having pair of spaced electrodes with a gas-filled gap therebetween, and including discrimination means, having a conductive mesh supporting a photocathodic material, positioned in the gasfilled gap between a first electrode having a layer of ultravioletemitting fluorescent material and a second electrode having a plastic sheet adjacent thereto for receiving photoelectrons emitted by the photocathodic material and accelerated to the second electrode by an applied field. The photoconductor-mesh element discriminates against fast electrons, produced by direct impingement of X-rays upon the photocathode to substantially reduce secondary electron production and amplification, thereby increasing both the signal-to-noise and contrast ratios. The electrostatic image formed on the plastic sheet is developed by zerographic techniques after exposure.</p> |