Automatic diaphragm control device of variable photometry type used in objective for television camera

摘要

An automatic diaphragm control device for the objective of a television camera, utilizing a video signal coming from the television camera to effect the diaphragm control The present invention provides a device including a fixed photometric circuit of a drastic peak characteristic in a part of a variable photometric circuit so as to be readily switched to perform a drastic peak photometric adjustment, in addition to an ordinary variable photometric adjustment, and also provides an automatic diaphragm control device of variable photometry type used in a television camera in which the variable photometric circuit is also arranged so as to be switched between the variable peak mode and the variable average mode so that a simple operation of changing over on one and the same circuit permits the variable photometry of both types to be selectively performed in order to obtain not only the drastic peak photometric characteristic but also versatile photometric characteristics optimized for various requirements.