Abstract: An apparatus for recording information on concentric circular recording tracks on a rotatable magnetic recording medium and/or reproducing the information from the recording tracks comprises a magnetic head provided in opposed relationship with the recording medium, a rotatable member, a driving device for intermittently rotating the rotatable member by a predetermined angle, a lever having a pivot shaft and intermittently pivoting in a predetermined direction about the pivot shaft by a unit pivot angle corresponding to the predetermined angle in response to the rotatable member, and a mechanism for intermittently moving the magnetic head in one direction on a straight line passing through the center of rotation of the recording medium in response to the pivoting lever, the head moving mechanism converting the pivotal displacement of the pivoting lever into rectilinear displacement.

Abstract: An automatic exposure control camera adjusts automatically the lens aperture in accordance with information on shutter speed determined in accordance with the brightness of an object or shutter speed set in accordance with manual setting from outside and information on the brightness of the object. The camera controls automatically the shutter speed in accordance with the information on the adjusted aperture value and the information on the brightness of the object. The camera can display a shutter speed value to which a preset shutter speed is automatically corrected when a proper exposure is not obtained even if the aperture is a fully open aperture.

Abstract: A camera comprising a detecting device capable of mounting an interchangeable lens having a signalling device for transmitting information of the fully open aperture of the lens to the camera and a diaphragm adapted to be controlled from said camera at the picture taking operation and further capable of detecting said information of the fully open aperture, andan exposure control device capable of calculating a combination of a diaphragm aperture and an exposure time for the exposure control at the picture taking operation from information of an object light received through the interchangeable lens and correcting the combination by means of the information obtained from the detecting device, or an exposure control device comprising a calculating circuit for calculating a combination of a diaphragm aperture and an exposure time for the exposure control at the picture taking operation from information of an object light received through said interchangeable lens and the information obtained from the detecting

Abstract: There is disclosed a mechanism for correcting programmed exposure values in a camera, the mechanism including a program exposure control device capable of correcting an exposure program in dependence upon the type of interchangeable lens and the condition of an object to be photographed.

Abstract: A diaphragm control apparatus for camera comprises a correcting circuit for correcting error in aperture stopping-down caused by a time lag from the generation of a signal for blocking the aperture stopping-down motion to the actuation of a blocking device in response to the signal.

Abstract: This invention relates particularly to a phototaking lens having at least a shutter speed priority automatic exposure system. The lens has a mount engageable with a mount of a camera body, which has a signal member operable when the lens is mounted and control means for making a caution and/or for stopping camera operation in response to an output of the signal member. The lens is further equipped with means for presenting the operation of the signal member, this means being disposed on the lens mount facing the signal member as the mount of the lens is engaged with the mount of the camera body. The signal member includes a retractable signal pin projected from the mount of the camera body and the preventing means includes a recess on the mount of the lens which is acceptable to the signal pin.

Abstract: An automatic exposure control camera adjusts automatically the lens aperture in accordance with information on shutter speed determined in accordance with the brightness of an object or shutter speed set in accordance with manual setting from outside and information on the brightness of the object. The camera controls automatically the shutter speed in accordance with the information on the adjusted aperture value and the information on the brightness of the object. The camera can display a shutter speed value to which a preset shutter speed is automatically corrected when a proper exposure is not obtained even if the aperture is a fully open aperture.

Abstract: An improved photographing mode switching mechanism is disclosed which is adapted for a camera provided with a switchover member movable between a first position in which non-diaphragm control mode is selected and a second position in which diaphragm control mode is selected. The improved photographing mode switching mechanism comprises a detection member for detecting the position of preset diaphragm ring of the lens tube and a control means for controlling the switchover member and the detection member. When the detection member detects that the diaphragm ring is in a position for the minimum aperture, the control means allows the switchover member to stay in the second position.

Abstract: An improvement in TTL metering system automatic control camera is disclosed. This type of camera requires a complicate control mechanism. According to the present invention, a substantial simplification of the mechanism is attained by providing the camera with a switch means interlocked with a shutter releasing operation and operable before the diaphragm being conrtrolled by a diaphragm control device, first and second holding circuits, a delay circuit, means for introducing the output of the first holding circuit into the diaphragm control device and means for introducing the output of the second holding circuit into a shutter control device.

Abstract: A spring servo type aperture control device in a camera having mounted thereon a lens comprises: an aperture mechanism including an aperture blade and determining the aperture by varying the position of said aperture blade, an aperture lever connected to said aperture mechanism and displaceable between a first position for rendering said aperture blade to an open aperture and a second position for rendering said aperture blade to a minimum aperture, and a member for biasing said aperture lever toward said second position, said aperture control device comprising: a control member engaged with said aperture lever and movable between a third position and a fourth position corresponding to said first position and said second position, respectively, a spring member storing a drive force by shutter charge and giving forth the stored drive force by shutter release, a cam member disposed between said control member and said spring member and rotatable by the drive force of said spring member upon shutter release to d

Abstract: A mirror driving device for use in a single lens reflex camera comprises a driving lever pivotally mounted to the body of the camera, a mirror pin movable integrally with the mirror, and biasing means provided on the driving lever. The mirror pin is surrounded by a bent portion provided at one end of the driving lever and two springs of the biasing means. One of the two springs has relatively strong biasing force and engages the bent portion, while the other spring has relatively weak biasing force and always biases the mirror pin in such a direction that the mirror may descend. Upon forwarding motion of the driving lever the mirror pin is moved by the end of said lever, thereby raising the mirror. Upon returning motion of said lever the mirror pin is moved by the two springs, thereby lowering the mirror. When the lever is in its original position the mirror is pressed in a viewing-focusing position solely with the biasing force of the other spring.