Abstract: A camera, adapted to function with film speed data, includes structure for introducing the film speed data and for storing that data. Manually set exposure time data is also stored. A determination is made whether the film is advanced to the first effective film frame. The film speed or exposure time data is alternately indicated and the indication is controlled to indicate the film speed data until the film is advanced to the first effective film frame subsequent to which the indication is switched to indicate the exposure time data when the film is advanced to the first effective film frame. The indication may subsequently be manually switched to indicate the film speed data. The film speed data may be read from the film cartridge upon closure of the back lid of the camera and transferred to storage.

Abstract: A flash photography system for a photographic camera and a flash device adapted to be connected thereto with the camera providing an aperture value output for flash light photography and a flash light stop signal obtained from an integrated output of the light reflected from a photographic object to terminate flash light emission when the integrated value reaches a predetermined value. The flash device calculates a maximum photographing distance covered by the flash light for effecting a correct exposure of the photographic object from the maximum flash light value and the aperture value from the camera. The maximum photographing distance is displayed by a suitable display visible to the camera operator.

Abstract: A mount arrangement for a photographic camera which is capable of automatic diaphragm control and automatic focusing includes electrical contacts for transmission of electrical signals between a camera body and an interchangeable lens unit, and mechanical transmission members for the automatic diaphragm control and the automatic focusing and positioning member and recess on and at inner periphery of mount members of the camera body and the lens unit so as not to interfere with each other during the start and the course of the mounting of the lens unit onto the camera body through a bayonet mount device.

Abstract: In a camera functioning with film speed data introduced by a manual operation for setting desired film speed data, exposure time data is set by a manual operation, and one of the film speed data and the exposure time data are alternatively indicated. The first and second indicating means are controlled, in response to first setting means such that the film speed data appears at the first indicating means when the first setting means is manually operated. The exposure time data is selected to appear at the first indicating means when the first setting means is not manually operated. The second indicating means is disabled when the first setting means is manually operated so that the film speed data appears without appearance of the additional data. The second indicating means is enabled so that the additional data appears with the exposure time data when the first setting means is not manually operated.

Abstract: An interchangeable lens unit is detachably attachable to a camera main body through an improved bayonet arrangement which includes three sets of corresponding bayonet claws, one of the corresponding bayonet claws of each set being provided on a mount member of the lens unit and the other on a mount member of the camera main body. The bayonet claws of the three sets are formed, in mutual dimension and dispositions thereof, such that the corresponding bayonet claws of one of the sets engage one another at an upper peripheral part of the mount members immediately above the center of the mount members and the corresponding bayonet claws of the remaining two sets engage one another respectively at lateral side peripheral parts of the mount members diametrically opposite to one another with respect to the center of the mount members in the lateral direction, when the camera main body and the lens unit attached thereto are viewed from their front with the camera main body held in a normal erect state.

Abstract: A camera has an automatic data reading arrangement for reading ISO data provided on a film cartridge. When a main battery is exchanged with an old battery while the film is still loaded in the camera, ISO data is maintained in a memory supported and powered by a back-up battery. If such an ISO data is not available after the exchange of the main battery, ISO data again read from the loaded film cartridge is employed. If the film is not the type that can provide an ISO data, the most widely used ISO data will be automatically set for the further exposure calculation.

Abstract: A mount arrangement for a photographic camera which is capable of automatic diaphragm control and automatic focusing includes electrical contacts for transmission of electrical signals between a camera body and an interchangeable lens unit, and mechanical transmission members for the automatic diaphragm control and the automatic focusing and positioning member and recess on and at inner periphery of mount members of the camera body and the lens unit so as not to interefere with each other during the start and the course of the mounting of the lens unit onto the camera body through a bayonet mount device.

Abstract: A flash photography system for a photographic camera and a flash device adapted to be connected thereto with the camera providing an aperture value output for flash light photography and a flash light stop signal obtained from an integrated output of the light reflected from a photographic object to terminate flash light emission when the integrated value reaches a predetermined value. The flash device calculates a maximum photographing distance covered by the flash light for effecting a correct exposure of the photographic object from the maximum flash light value and the aperture value from the camera. The maximum photographing distance is displayed by a suitable display visible to the camera operator.

Abstract: A flash photography system using a first aperture value output calculated from a desired diaphragm aperture value for flash light photographing with data obtained from ambient light, film sensitivity and the exposure data, a second aperture value output independent of the light value of the ambient light, data selecting circuitry for outputting any one of the first aperture value output and the second aperture value output, an aperture controller for controlling the actual diaphragm aperture size from the output of the data selecting circuitry, and means for producing a stopping signal to stop the emission of the flash light when the flash light emission reaches a predetermined value.

Abstract: A mount arrangement for a photographic camera which is capable of automatic diaphragm control and automatic focusing includes electrical contacts for transmission of electrical signals between a camera body and an interchangeable lens unit, and mechanical transmission members for the automatic diaphragm control and the automatic focusing and positioning member and recess on and at inner periphery of mount members of the camera body and the lens unit so as not to interfere with each other during the start and the course of the mounting of the lens unit onto the camera body through a bayonet mount device.

Abstract: An automatic exposure control camera is of a type capable of controlling both the camera exposure and the flash light amount to be emitted by an electronic flash device. The automatic exposure control camera includes an average light measuring device for measuring an amount of the entire light impinging on an image forming plane and for producing an average signal representing the average light amount, and a spot light measuring device for measuring an amount of light impinging on a spot of the image forming plane and for producing a spot signal representing the light amount at the spot.

Abstract: An exposure system for a camera includes a light emitting apparatus for emitting an artificial light toward an object. The light emitting apparatus is capable of selectively emitting a first type of light which flashes instantaneously, and a second type of light which flashes for a prolonged period of time. The intensity is maintained constant during the prolonged period of time. A camera produces a mode signal for switching the light emitting apparatus between a first mode in which the instantaneous flash light is emitted and a second mode in which the prolonged flash light is emitted.

Abstract: An exposure system for use in a camera includes a light emitting apparatus which is capable of selectively projecting a first type of light which flashes instantaneously with a predetermined light quantity and a second type of light which flashes for a prolonged period of time with a predetermined constant light intensity, and a selecting circuit for selecting the first type of light when a target object to be photographed is located a predetermined distance away from the camera, and the second type of light when the target object is located closer to the camera than the predetermined distance.

Abstract: In a photographic system for flash photography, the firing current of an electronic flash tube is selectively restricted in accordance with the detection of whether or not the flash light amount necessary for a flash photograph is below a predetermined level prior to the firing of the flash tube for a photographic exposure. A selection is made between a first mode of flash firing with flash tube current flowing through a switching element and a second mode of flash firing with a flash tube current flowing through an impedance device serially connected with the flash tube. Alternatively, a selection can be made between higher or lower voltage levels to which the main flash firing capacitor is charged. The amount of light required from a flash device can be preparatorily identified and when less than a predetermined light output the flash device is caused to select the second mode of flash firing, or alternatively to select the lower level of the voltage charged by the main capacitor.

Abstract: In a single lens reflex camera including a camera body provided with a film receptacle, a film transporting mechanism and an operating member for effecting film advancing and shutter cocking; a shutter block in which shutter blades or the like and shutter actuating and controlling mechanism are associated as a unit on a base plate; and a front plate formed with a mount for the camera objective lens and having attached thereto a mirror box which is provided with a reflex mirror, a mirror driving mechanism and a diaphragm driving mechanism, the front plate assembly to which the shutter block is coupled is attached to the camera body, whereby interconnection between the shutter mechanism, the mirror and the diaphragm mechanism is improved.

Abstract: A motor driven camera has a detachable drive unit, and includes a motor drive circuit which is activated for driving a film wind-up and shutter charge motor on receipt of a signal representative of termination of an exposure. The camera also includes a selector capable of being set at a single frame photographing position as well as at a continuous photographing position, and a control mechanism for preventing generation of the signal with the selector set at the single frame photographing position. A signal generating device is associated with a film wind-up stop mechanism for generating the signal when the stop mechanism is disengaged from a film wind-up and shutter charge mechanism in response to termination of an exposure, disengagement of the stop mechanism being prevented or the signal generating device being deactivated by the control mechanism when the selector is set at its single frame photographing position.

Abstract: An electrical drive which includes a motor for actuation of a film wind-up and shutter mechanism subsequent to exposure of a film frame and a mechanism for decoupling drive from the motor at the end of each wind-up and shutter charge action and also during this action if something occurs a fault preventing correct action of the film wind-up and shutter charge mechanism, whereby damage to the mechanism, the motor and film is prevented. The drive is correctly positioned with respect to a camera by a mechanism which also serves to provide electrical connection between a shutter control circuit and a drive control circuit, whereby the number of elements required to be precisely positioned with respect to the camera is less and manufacturing and assembly cost is reduced.

Abstract: In a single lens reflex camera including a camera body provided with a film receptacle, a film transporting mechanism and an operating member for effecting film advancing and shutter cocking; a shutter block in which shutter blades or the like and shutter actuating and controlling mechanism are associated as a unit on a base plate; and a front plate formed with a mount for the camera objective lens and having attached thereto a mirror box which is provided with a reflex mirror, a mirror driving mechanism and a diaphragm driving mechanism, the front plate assembly to which the shutter block is coupled is attached to the camera body, whereby interconnection between the shutter mechanism the mirror and the diaphragm mechanism is improved.

Abstract: A single lens reflex camera includes an electromagnetic release device in which a locking mechanism including an armature is moved to an inoperative position under a spring force to release the locking of a drive member when a solenoid generates a magnetic force to cancel the magnetic attractive force of a permanent magnet, which attractive force attracts the armature to a core, thereby maintaining the locking mechanism in an operative position. The drive member thus released actuates an exposure initiating mechanism of the camera to start exposure operations. In response to the completion of the closing of the shutter, a signal member moves to release a spring loaded resetting member from locking by another locking mechanism.

Abstract: A camera includes a stroke change-over member which is in first position and a second position respectively when a shutter dial is set for electric exposure control mode and for mechanical exposure control mode. The stroke change-over member, when in the first position, restricts the stroke of the movement of a mechanical release initiating member and, when in the second position, allows the movement of the mechanical release initiating member beyond the restricted stroke, the movement being caused by depression of a shutter button. The camera further includes an electromagnetic release initiating member movable from a first to a second position in response to the depression of the shutter button and a locking member for locking the electromagnetic release initiating member at the first position when the shutter dial is set for mechanical exposure control.