Abstract: An exposure control device in which the output of a light measuring circuit which produces an electrical signal corresponding to the brightness of an object is compared with an output of a level signal circuit which produces an electrical signal of a predetermined level. When the compared value reaches a predetermined value, a flash circuit is made ready to flash, whereby the shutter time is changed over to a predetermined time suited for a flash photography and the flash circuit is made to flash in association with the shutter operation and the shutter is controlled with a constant time.

Abstract: A selector circuit interrupted by an electrical signal from an attachment selectively mounted on the camera body and is connected in the light receiving circuit as well as the exposure determining circuit provided in the camera. When the above mentioned unit is mounted on the camera the exposure determining circuit provided in the camera is automatically connected from the light receiving circuit to the output terminal of the unit by means of the selector circuit, so as to receive the exposure value signal on the unit and set the exposure value corresponding to the exposure value signal.

Abstract: The present invention relates to various kinds of the flash light photographic systems consisting of a combination of either of the below mentioned cameras with either of the below mentioned flash light device;A camera CD presenting an input terminal of the information for controlling the diaphragm and the output terminal of the information for the set aperture,A flash light device SD presenting the output terminal of the information for controlling the diaphragm and the input terminal of the information of the set aperture,A camera CT presenting an input terminal of the information for controlling the diaphragm,A camera CA presenting an output terminal of the information of the set aperture,A flash light device ST presenting an output terminal of the information for controlling the diaphragm,A flash light device AS presenting an input terminal of the information of the set aperture.

Abstract: A flash exposure control system comprising a flash lighting unit, a battery circuit connected to said flash lighting unit to energize said flash lighting unit during an exposure, a switching arrangement connected to said flash lighting unit to control the termination of energization of said flash lighting unit, a timer for controlling the conduction of said switching arrangement, the timer having an adjustable circuit for adjusting the duration of conducting time as a function of the camera-to-object distance and the adjustable circuit being responsive to the camera focus adjustment, and an aperture adjusting unit responsive to the focus adjustment for defining an exposure aperture.

Abstract: A camera system is composed of a flash and a camera in which the diaphragm and shutter time control as well as the indicating mechanism are automatically switched into a flash mode in response to the charge accumulation completion signal from the electronic flash discharge device.

Abstract: The present invention refers to an apparatus for taking photographs of an object in close proximity by means of a flash. A proper exposure is obtained for the object in close proximity with the use of flash equipment with variable illumination intensity, in accordance with the equation ##EQU1## L: Distance to the object M: Photographic magnificationa: ConstantN: Film sensitivityPe: Effective lighting quantityF: Aperture of diaphragmThe flash equipment is designed in such a manner that the flash light part of the flash equipment can nearly be brought in alignment with the optical axis of the objective of the photographic camera while the illumination intensity of the flash light can be varied.

Abstract: The present invention relates to the flash photographic system for camera which is characterized in that the system presents a safety device for preventing various misoperations generally apt to take place at the time of taking a photograph by using a flash light device. By means of the operation of this device, the shutter time is set at a certain determined time for taking a photograph under flash light with the shutter time setting means at the camera side whereby the flash light photographic mode setting signal can be obtained only when the light device is set at the state ready for flash lighting in such a manner that the camera is capable of taking a photograph under flash light only when this signal is obtained.

Abstract: A flash photographic exposure control system for a camera having an electrically timed shutter is provided with an additional electronic or mechanical timing device in combination with an electronic changeover switch responsive to attainment of the threshold level of the flash unit associated therewith. This is done to switch the camera from an automatic daylight exposure range to an automatic flash exposure range in which a particular timed interval suited for flash photography is made by the timing device which is brought into cooperation with the shutter operating means when the changeover switch is actuated, while the intrinsic timing device for the shutter being cut off from the control means for the shutter.

Abstract: The time period necessary to charge a current-to-light convertible energy storing capacitor to a certain voltage is reduced as compared with prior art devices. The energy storing capacitor is connected across a flash tube and switching element series-connected with each other. The switching element is provided with a control circuit, responsive to the voltage of the storage capacitor decreasing to a level at which the flash tube is stopped from producing flash light, for producing a terminating signal by which the switching element is brought into the open or non conducting state. With this arrangement, it is made possible to prevent complete discharge of the electric charge stored in the storage capacitor from occurring, thereby providing the advantage of saving a good fraction of the charging time period which would be otherwise necessary when the storage capacitor is completely discharged to zero voltage.

Abstract: A device for automatic control of the quantity of light from an electronic flash tube including a silicon controlled rectifier connected in series with the flash tube, a circuit for applying a reverse voltage between the main electrodes of said silicon controlled rectifier so as to open said rectifier, and a switching element connected between said reverse voltage applying circuit and said silicon controlled rectifier. Responsive to the output signal from the reverse voltage applying circuit, the switching element short-circuits the gate electrode and cathode of the rectifier. With this arrangement, it is possible to decrease the capacity of a commutation capacitor constituting part of the reverse voltage applying circuit.

Abstract: A photographic flash exposure control system for a camera associated with a flash device. In conformance with a preselected shutter interval, an effective exposure aperture of a diaphragm device is computed by a computing circuit of the system. The total flash energy available from the flash device is automatically controlled in accordance with the luminance of the subject being photographed, to thereby provide correct exposure for complex lighting situations.