Iris controller of camera

Abstract

Abstract PURPOSE: To eliminate iris setting operation at the time of strobo-flash picture taking, by providing preliminary flashing of the strobo at a certain intensity prior to exposure, thereby making it possible to set the specified iris value automatically. CONSTITUTION: Block 30 is an exposure-time formation circuit, which commences integration of currents proportionate to the brightness of the object in synchronization with shutter-opening operation, and outputs signals which reverse from the low to high level when the prescribed integration value is reached. This exposure- time formation circuit 30 consists of logarithmic compander type transistor 31, current integrating capacitor 32, etc. Output terminal 9a of information computation circuit 8 is connected to light-emission stop signal input terminal 40 of strobo 37. Thus strobo 37 gives out light for a certain duration by the making of the preliminary flashing switch 38, thereby obtaining flash light necessary for optimum exposure in synchronization with the full opening of the shutter. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Tokuji Ishida
• 👤 Toshio Kobori

Bibliographic Details