Control system for single lens reflex camera

Claim 1

An automatic exposure control system for a single lens reflex camera including a camera body and a film, comprising: means manually operable for shutter release; diaphragm means for defining a diaphragm aperture; diaphragm driving means for driving said diaphragm means to change the diaphragm aperture in response to manual release operation; photoelectric means for receiving light from an object to be photographed through the diaphragm aperture; light measuring means including said photoelectric means for generating a first signal as a function of the light received by said photoelectric means, said first signal being dependent on the diaphragm aperture; means for manually setting a shutter speed; means for generating a second signal as a function of the manually set shutter speed; means for timing the shutter closure; selection means for selectively connecting said means for timing to said light measuring means and to said means for generating a second signal; means for setting a film sensitivity; means for generating a third signal as a function of the set film sensitivity; comparison means for comparing said first, second and third signals and generating a fourth signal with said first and third signals reaching a given relationship with said second signal; first electromagnetic means for arresting said diaphragm driving means in response to the generation of said fourth signal; a reflex mirror means movable between a viewing and a photographic position; second electromagnetic means for actuating, in response to the generation of said fourth signal, said reflex mirror means from said viewing to said photographic position, and including a first switch member actuatable with said diaphragm driving means travelling to a terminal position, an electromagnetic member for actuating said mirror, a first switch means for actuating said electromagnetic member in response to said fourth signal, and second switch means for actuating said electromagnetic member in response to the actuation of said first switch member; shutter means actuated, with said reflex mirror reaching said photographic position, to commence exposure and including a focal plane shutter member with light reflection characteristics; and said photoelectric means further includes a first photoelectric member disposed in said camera body to receive the light from the object through the diaphragm aperture with said reflex mirror at said viewing position, and a second photoelectric member disposed in the camera body to receive light from the object through the diaphragm aperture by reflection from said focal plane shutter member and/or film.