Direct view imaging tube incorporating velocity selection and a reverse biased diode sensing layer

Claim 1

An image device comprising an input sensing member comprised of a wafer of semiconductive material of a first type of conductivity having an input and an output surface, a plurality of regions of semiconductive material of a second type of conductivity of opposite type conductivity to said first type on the output surface of said wafer and extending into said wafer a discrete distance and forming a plurality of junctions, said input sensing member exhibiting the property of generation of electron-hole pairs in response to incident radiation directed onto said input surface, means for reverse biasing said junction comprising a photoemissive element and means for electrically connecting the photoemissive element with each of said regions and means for illuminating said photoemissive elements, an output screen associateD with said photoemissive elements to generate a light image in response to the photoelectrons emitted from said photoemissive elements striking said output screen, a first grid positioned adjacent to said photo-emissive elements for accelerating the photo-electrons emitted from said photoemissive elements and a second grid positioned between said accelerating grid and said output screen for velocity selection of the photoelectrons emitted from said photoemissive elements and passing through said accelerator grid, said sensing member responsive to said input radiations to modify the potential of said photoemissive elements.