Document Type and Number:
Japanese Patent JPS5433132
Kind Code:
B1
Abstract:
1363248 Photographic apparatus CANON KK 22 Dec 1971 [28 Dec 1970] 59801/71 Heading G2A An interchangeable photographic lens, intended for use with a single-lens reflex camera, has an electrically-operated iris diaphragm, actuated by a coupling member 5-2 on the lens body or on an extension tube and a switch S1. As a result, the diaphragm of a long telephoto lens can be coupled to the camera body 2 without the necessity for any long mechanical member to be present. A preview button 10 on the camera body may be made to operate a switch S2 in the electric circuitry of the lens, to cause the diaphragm to stop down temporarily to an opening set by a rotatable pre-set ring 13. When the shutter button of the camera is depressed, and coupling lever 4 moved in consequence, the switch S1 is closed, and the diaphragm is stopped down prior to exposure. Alternatively, the switches S1 and S2 may be replaced by a single switch, operable either by the coupling member 5-2 or by a rod actuated by the preview button. A delay means may be incorporated to allow the diaphragm to close fully before the shutter fires.
Application Number:
JP12391770A
Publication Date:
October 18, 1979
Filing Date:
December 28, 1970
Export Citation:
International Classes:
G03B9/02; G03B9/07; G03B19/12; (IPC1-7): G03B9/07