A device for enhancing video reception from a silicon target vidicon by rction of smeared images. Conventional television scanning parameters are used to display images of the scene being viewed. Light rays from the scene are impinged upon a silicon target of photodiodes within the vidicon. A circuit is provided for grounding the target electrode between successive vertical scans of the electron beam thus reducing the time during which smearing of the image occurs.
A black-white or color television camera has a pick-up tube having a signal electrode comprising separate strips. Before a line scanning operation to be performed by an electron beam takes place, the signal electrode strips are coupled to a reference potential. After the line scan, the strips which are coupled separately to parallel inputs of a switching circuit which is provided with switches coupled to the parallel inputs, are coupled for supplying video information. This results in a separation between electron beam scanning and picture signal supply by the pick-up tube, which has the advantage that the beam scanning does not affect the picture quality in the direction of line scan. Furthermore, the construction with strips yield an improved signal-to-noise ratio. The switching circuit may, possibly together with a shift register, be integrated in a semiconductor body, which is provided near the signal electrode in the pick-up tube or outside the pick-tube.
This camera comprises an electron tube with a photosensitive target (6) made of single-crystalline semiconducting material, lens (10) for forming the image of a scene on the target, an electron gun (14) to supply an electron beam to read the target, and scanning and focusing portion (18) designed to force the target to be scanned by this electron beam and to focus this electron beam on the target. The target then outputs a signal representative of this image. The camera also includes an electronic processing circuit (20) for controlling the electron gun and scanning and focusing of the camera and receiving and storing circuits (22) for receiving and storing the signal. Application to the analysis of very fast movements.
The target of a television camera tube comprises photoconductive material in the form of a regularly interrupted structure so that both the photoconductive material and parts of the signal electrode are accessible to the electron beam. The potential difference between the signal electrode and the cathode is adjusted so that during scanning, the signal electrode accepts a proportion of the beam current dependent on the local potential of the photoconductor surface, and the photoconductor is stabilized only during fly-back. The camera tube thus has an adjustable inherent amplification without increased inertia.
