Watson, Cole, Grindle & Watson
Indicating device for single lens reflex camera
 An exposure indicating device for single lens reflex cameras which are selectively settable to automatic aperture control or automatic shutter speed control modes includes an exchangeable lens which has first and second information transmitting members, and a diaphragm setting member settable to one of a number of manually set aperture positions. The first transmitting member transmits to a first information receiving member, first information of the step-difference from a minimum to a preset f-number of the lens independently of the set position of the diaphragm setting member. The second transmitting member transmits to a second information receiving member, second information of a maximum f-number only when the diaphragm setting member is set to select a maximum f-number. A camera body is provided with a modes selecting member which switches the camera either into the automatic aperture control mode or into the automatic shutter speed control mode and enables observation of either an aperture scale or a shutter speed scale within a finder view field. The first information thus received enables automatic shutter speed control, and indication of an automatically controlled shutter speed prior to a stopping-down operation. The first and second information thus received are composed with each other, only in the automatic aperture control mode, to generate information of the minimum f-number of the lens, which enables indication of an f-number corresponding to an automatically controlled aperture prior to the stopping-down operation. 
Minolta Camera Kabushiki Kaisha
G
G03B
inventional
Keiji Horoshi Kunio
Yamazaki Ueda Kawamura