Automatic beam current control system for television camera

摘要

In an image pickup apparatus or television camera tube in which a signal corresponding to a target current of the television camera tube is supplied to its beam current control electrode to thereby control the beam quantity to become corresponding to the variation of the incident light amount thereon, the present invention is to provide an automatic beam current control system for a television camera in which the signal corresponding to the target current is supplied through a line adder circuit to the beam current control electrode. The line adder circuit may use, for example, a one horizontal period delay line. Since the control signal supplied to the beam current control electrode is an added value or an average value of the target currents obtained over two scanning periods, the stable control signal is always supplied to the beam current control electrode of the television camera tube so that the image picked up signal of high definition without a line crawl component can be obtained.