Abstract: A means is provided for use with a camera of the type having an electrical shutter and which is adapted to utilize a strobo unit. The said means comprises a first circuit including a capacitor and a resistor connected in series across the X contacts of said camera and a second circuit connected with said first circuit and producing a shutter closing signal. The capacitor is charged by power means in the strobo unit. The X contacts close to cause the strobo unit flash means to operate and, at the same time, discharging said first circuit means and triggering the second circuit means to produce a shutter closing signal for closing the shutter at that time unless the shutter has already been closed. Additional circuit means may be provided between said first and second means for delaying operation of said second circuit means.

Abstract: A camera includes a sliding case, which is movable between a first position in which it covers a region of the camera including at least a taking lens thereof and a second position in which the taking lens is exposed. The case is operatively connected with other mechanisms such as a film winding mechanism, a shutter charging mechanism or the like, and is also operatively connected with a power switch for an electrical circuit such as a photometric device or a strobo unit. A reciprocating movement of the case between the two above-mentioned positions establishes a photographable condition of the camera in which the taking lens is exposed.

Abstract: A strobo unit is disclosed for use in association with a camera provided with a changeover switch operating between an automatic exposure mode and a flashlight mode and normally placed in the automatic exposure mode, and with an accessory shoe connected with the X contacts internally housed within the camera, the switch and the shoe being located on adjacent exterior surfaces of the camera.

Abstract: A single lens reflex camera of compact construction provided with high and low speed controlling mechanisms for a shutter blind wherein the high speed controlling mechanism is received in a space defined by the bottom end of the winding shaft of the shutter, the base of a reflector body and the bottom wall of the camera body.

Abstract: A photometric apparatus for single lens reflex camera and of the type in which an exposure value is determined by photometry of light which is transmitted through a photographic optical system and is reflected by at least one of the surfaces of a shutter blind and a film, said apparatus comprising a photoelectric transducer element for receiving light reflected by at least one of the surfaces of a shutter blind and a film, and an operational amplifier for biasing the photoelectric transducer element to maintain the voltage applied thereacross substantially null, thereby enabling a photometric output of the photoelectric transducer element to be effectively derived even when the amount of light received is minimal.

Abstract: An exposure indicator for a camera having an electrical shutter capable of taking pictures under both automatic exposure and manual exposure.

Abstract: A data display for use in a strobo unit which includes a manual controlling device for manually controlling the illumination, an automatic controlling device for controlling the illumination by means of a light receiving element which serves as means for determining an external light, and a TTL controlling device for controlling the illumination by means of a second light receiving element disposed within the camera for determining reflected light from a shutter blade or a film surface. The data display comprises a first stationary display panel carrying a diaphragm aperture dial and a guide number dial for use in a manual control mode, a diaphragm aperture dial and a range dial for use in an automatic control mode, and a plurality of indicia for selection of the manual, automatic and TTL controlling devices, all disposed in interrelated and concentric relationship.

Abstract: An apparatus for activating an electronic flash by operating an X contact when the first blind of a focal plane shutter has terminated its movement to fully open an exposure light path, irrespective of an exposure period establishing operation. Where an electronic focal plane shutter is combined with an auto-strobo, a photometric circuit within the electronic circuit is used to measure the radiation from the auto-strobo, and to control the amount of exposure to a proper value. Where a proper amount of exposure is available by natural light when the shutter is opened, a closing movement of the shutter is utilized to cause the trigger capacitor of the electronic flash to be discharged, thereby disabling the illumination of the electronic flash.

Abstract: A photometric apparatus for single lens reflex camera and of the type in which an exposure value is determined by photometry of light which is transmitted through a photographic optical system and is reflected by at least one of the surfaces of a shutter blind and a film, said apparatus comprising a photoelectric transducer element for receiving light reflected by at least one of the surfaces of a shutter blind and a film, and an operational amplifier for biasing the photoelectric transducer element to maintain the voltage applied thereacross substantially null, thereby enabling a photometric output of the photoelectric transducer element to be effectively derived even when the amount of light received is minimal. The shutter blind is provided with a surface upon which at least two portions thereof have different coefficients of reflectivity to reduce adverse effects of reflected light upon the desired exposure period.

Abstract: A photometric apparatus for single lens reflex camera and of the type in which an exposure value is determined by photometry of light which is transmitted through a photographic optical system and is reflected by at least one of the surfaces of a shutter blind and a film, said apparatus comprising a photoelectric transducer element for receiving light reflected by at least one of the surfaces of a shutter blind and a film, and an operational amplifier for biasing the photoelectric transducer element to maintain the voltage applied thereacross substantially null, thereby enabling a photometric output of the photoelectric transducer element to be effectively derived even when the amount of light received is minimal. The photometric apparatus, including a photoelectric transducer element, a photometry switch and associated circuitry are mounted upon a printed circuit board mounted within the camera to position the transducer element to receive reflected light from the film or the shutter.

Abstract: An electrical focal plane shutter is provided of a type in which subsequent to a running of a first blind of the shutter, a second blind of the shutter is constrained from movement by an electromagnet until a desired exposure period passes, whereupon the electromagnet is deenergized to permit a running of the second blind. The electromagnet is controlled by an electromagnet control device including a light receiving element which is used for photometry. The shutter includes a shutter detent mechanism for preventing a shutter release operation when an electric storage battery contained in an associated camera is exhausted. The shutter further includes a high speed shutter operation control mechanism which assures against the instability of the operation of the electromagnet when the shutter is operating at a high speed, and also includes a manual shutter control mechanism for establishing a shutter operation period of a given length in a purely mechanical manner.

Abstract: An electrical shutter circuit for a camera includes a photoelectric transducer element which is responsive to light from an object being photographed to determine a proper exposure period in accordance with the brightness thereof, thus automatically controlling the operation of a shutter assembly which opens or closes an exposure light path. In the open position of the shutter assembly, the photoelectric transducer element is irradiated with light of a fixed, relatively low intensity emitted by a luminescent element so that the electrical shutter circuit is automatically operated for the closing operation after a period of time determined by the light from the luminescent element even if the incident light from the object being photographed is extremely weak or completely absent.

Abstract: A photometric apparatus for single lens reflex camera and of the type in which an exposure value is determined by photometry of light which is transmitted through a photographic optical system and is reflected by at least one of the surfaces of a shutter blind and a film, said apparatus comprising a photoelectric transducer element for receiving light reflected by at least one of the surfaces of a shutter blind and a film, and an operational amplifier for biasing the photoelectric transducer element to maintain the voltage applied thereacross substantially null, thereby enabling a photometric output of the photoelectric transducer element to be effectively derived even when the amount of light received is minimal.

Abstract: An apparatus for activating an electronic flash by operating an X contact when the first blind of a focal plane shutter has terminated its movement to fully open an exposure light path, irrespective of an exposure period establishing operation. Where an electronic focal plane shutter is combined with an auto-strobo, a photometric circuit within the electronic circuit is used to measure the radiation from the auto-strobo, and to control the amount of exposure to a proper value. Where a proper amount of exposure is available by natural light when the shutter is opened, a closing movement of the shutter is utilized to cause the trigger capacitor of the electronic flash to be discharged, thereby disabling the illumination of the electronic flash.