Abstract: In a diaphragm actuator of a lens of a camera comprising a stationary support ring, a blade ring which is rotatable in the support ring and which has pivotable diaphragm blades movably connected to the support ring so that the rotational movement of the blade ring causes the diaphragm blades to open and close, and a limiting member which comes into contact with the blade ring to limit the movement of the blade ring when the diaphragm blades are closed, the improvement comprising an additional ring rotatable relative to the support ring for preventing the blade ring from bounding when the blade ring contacts with the limiting member, which additional ring comes into contact with the balde ring to brake the movement of the blade ring immediately before the blade ring contacts with the limiting member.

Abstract: A camera has first and second displaceable actuators and a diaphragm adjustable between a maximum aperture value and a minimum aperture value responsive to displacement of the second actuator. A first signal is generated that is representative of the displacement of the first actuator. A second signal is generated that is representative of a desired aperture value of the diaphragm for correct exposure. A first and second signal are compared. The first actuator is displaced upon shutter release, but the second actuator remains stationary during an initial portion of the displacement of the first actuator and is displaced as a unit with the first actuator during the remainder of the displacement of the first actuator. When the first and second signals assume a predetermined relationship as indicated by the comparison, displacement of the actuators is arrested and the proper aperture value is provided.

Abstract: An automatic aperture presetting device for a camera lens having a crank lever pivotally mounted on a preset ring which is rotatable around the optical axis of the lens. The end of one arm of the lever is in abutment against the edge of a cam which is mounted on a stationary lens barrel while the end of the other arm of the lever is operatively coupled to a stop member of an aperture operation ring which is driven from a corresponding member on the camera body side to thereby obtain an automatic aperture value corresponding to a set position of the preset ring.

Abstract: A camera body having a camera body and an interchangeable lens engageable with the camera body has an improved contact arrangement between camera body and lens. A lens mount has a first flat surface, a camera mount engages a lens mount to join the lens to the camera body, and the camera mount has a second flat surface abutting the first flat surface when the lens mount engages the camera mount. One or more first electrical contacts in the lens mount are movable normal to the first surface between a retracted position approximately flush with the first surface and an extended position projecting from the first surface. A spring urges the one or more first contacts toward the extended position.

Abstract: An automatic aperture control device adapted to be fitted in a lens barrel of an automatic aperture control camera in which the aperture value is controlled in accordance with the stop position of the camera. Pairs of aperture blades and intermediate levers are pivotally mounted on a support ring with a first drive shaft of each intermediate lever mounted in a corresponding aperture of an opening and closing ring and a second drive shaft of each intermediate levers slidably mounted in an elongated groove formed in a corresponding aperture plate. The elongated groove is formed such that the amount of variation of an outer radius of the aperture blade is minimized with a result that smooth and precise aperture control is achieved over the entire range of aperture values.

Abstract: A photographic lens mount has a tripod portion that is rotatable about the optical axis of the lens. A rack and pinion type of focussing mechanism is used and the pinion is fixed with respect to the tripod mounting seat irrespective of the rotational position of the lens support and the camera body. The ring portion of the gear mechanism is formed on a ring that is rotatable with respect to the camera support around the optical axis.

Abstract: A camera lens barrel suitable for flash photography, wherein flash guide numbers are marked either on the distance adjusting ring or the diaphragm value adjusting ring, is disclosed. The distance adjusting ring and the diaphragm value adjusting ring are so arranged that the rotational angle of the distance adjusting ring required to increase the distance gradation value by the .sqroot.2 is equal to the rotational angle of the diaphragm value adjusting ring at that time. A clutch mechanism is mounted in the camera lens barrel and arranged so that the distance adjusting ring and the diaphragm value adjusting ring are coupled together during flash photography. The coupling is such that the distance adjusting ring and the diaphragm value adjusting ring are connected together at a relative angular position corresponding to a flash guide number.