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AssigneeSeiko Koki Kabushiki Kaisha
InventorsYuzuru Takazawa, Shinji Nagaoka
Estimating the term…
In a program shutter of the type in which the aperture opening gradually increases with the lapse of time, informations such as sensitivity of the film and the object distance are introduced by an electric circuit. The system has a switching circuit for exposure control. The trigger level of the switching circuit is determined in proportion to the film sensitivity and the object distance to vary the exposure control time corresponding to the informations to automatically determine a proper aperture for flash photography. The system is capable of providing a warning indication prior to the shutter operation if the exposure control time thus obtained is longer than the time during which the aperture is fully opened.
In a program shutter control circuit having a switching circuit connected to the output of a time constant integrating circuit comprised of a condenser and a photoconductive element, and an electromagnet connected to the output of said switching circuit for controlling the closing operation of the shutter:
In an electric shutter control circuit operable in a flash photography mode and having an energizeable electromagnet for controlling the closing operation of the shutter, a switching circuit switchable between two switching states to control the energization of said electromagnet, and means for setting film sensitivity information and object distance information:
Dependencies are inferred from the claim text.