Camera tube having a target formed by an array of phototransistors

摘要

A vidicon camera tube is disclosed. The camera tube includes an electron gun at one end thereof for projecting a beam of electrons over a beam path to a target electrode formed by a photosensitive array of phototransistors. Deflection plates are provided intermediate the electron gun and target for scanning the electron beam over the array of phototransistors to derive an electrical signal in accordance with the photon image which is illuminating the array of phototransistors. The phototransistors each include one exposed terminal facing the scanning electron beam. A capacitor structure is formed on the beam scanned side of the array of phototransistors for providing substantially increased capacitance between the scanned terminals of the phototransistors and a source of stable potential such as ground potential. By providing the capacitance between the scanned terminals and ground the photon gain of the phototransistors is greatly increased above 1, thereby substantially increasing the sensitivity of the camera tube and therefore its resolution.