Solid-state diode array camera tube having electronic control of light sensitivity

Claim 2

An optical image conversion device comprising a semiconductor substrate of one impurity type having an array of discrete regions of the other impurity type forming an array of semiconducTor detecting junctions on one surface of the substrate, said junctions being arranged to collect photongenerated minority carriers produced by light incident upon the surface of the substrate opposite said one surface, a single thin layer of material being disposed uniformly upon said opposite surface of the substrate to form a single large area uniform semiconductor junction adjacent the portion of said opposite surface upon which the light is incident, and means for reverse biasing the large area uniform junction, said bias means being variable to control the width of the depletion layer formed by the uniform junction so that the variation of the width of said depletion layer controls light sensitivity, the layer acting as a sink for minority carriers generated by photons in the depletion region.

Claim 3

An optical image conversion device as claimed in claim 1 wherein the material forming the thin layer is a semiconductor material of the other impurity type.

Claim 4

An optical image conversion device as claimed in claim 2 wherein said substrate is an N-type material, and said large area uniform junction is formed by diffusing a thin layer of P-type material upon the N-type substrate.

Claim 5

An optical image conversion device as claimed in claim 1 wherein said large area uniform junction is formed by sputtering a metal upon the substrate to form a Schottky barrier type diode junction.

Claim 6

An optical image conversion device as claimed in claim 1 wherein the width of the depletion layer is varied by varying the bias voltage applied to the large area uniform junction, with the means for reverse biasing having only two electrical connections to the target.

Claim 7

In a solid-state video camera target system of the type comprising a bulk semiconductor material having a light incident surface, a portion of the incident surface being an imaging area upon which light from a scene is incident, a diode array arranged on a surface of the bulk material opposite the light incident surface, means including a scanning electron beam for biasing the diode array such that minority carriers generated in the substrate by the incident light are attracted toward the diode array and for removing from said target a video current proportional to the number of attracted carriers, and means for controlling the number of carriers attracted to the diode array characterized in that, said means for controlling includes a single thin layer of material on the light incident side of the target, said layer forming a single large area semiconductor junction formed over the entire imaging area, means for reverse biasing said junction to produce a depletion region in the bulk material adjacent to said large area junction, and means for varying the reverse bias voltage to vary the width of the depletion region so that varying the width of said depletion region controls light sensitivity, the layer acting as a sink for minority carriers generated by photons incident in the depletion region.

Claim 8

In a solid-state video camera target system of the type comprising a bulk semiconductor material having a light incident surface, a portion of the incident surface being an imaging area upon which light from a scene is incident, a diode array arranged on a surface of the bulk material opposite the light incident surface, means including a scanning electron beam for biasing the diode array such that minority carriers generated in the substrate by the incident light are attracted toward the diode array and for removing from said target a video current proportional to the number of attracted carriers, and means for controlling the number of carriers attracted to the diode array characterized in that, said means for controlling includes a single thin layer of material on the light incident side of the target, said layer forming a single large area semiconductor junction formed over the entire imaging area, means for reverse biasing said junction to produce a depletion region in the bulk material adjacent to said large area junction, and means for varying the reverse bias voltage to vary the width of the depletion region so that varying the width of said depletion region controls light sensitivity, the layer acting as a sink for minority carriers generated by photons incident in the depletion region.