Abstract: An electronic flash apparatus for flash photographing comprises flash discharge means, means for supplying a voltage to the flash discharge means, first light emission control means comprising first trigger means for triggering the flash discharge means to cause a discharge therein, for the purpose of the flash photographing and second light emission control means. The second light emission control means comprises oscillator means for generating periodic output signals, second trigger means for periodically triggering the flash discharge means in response to the periodic output signals thereby periodically initiating the discharge in the flash discharge means, detecting mean for generating an output signal upon detection of the initiation of the discharge in the flash discharge means and means for terminating the discharge in the flash discharge means in response to the output signal of the detecting means.

Abstract: An electronic flash device of a camera comprises first flash means for emitting a flashlight, second flash means for emitting a flashlight, means for detecting that the first flash means has started to emit a flashlight and for producing a detection signal, and means responsive to the detection signal to cause the second flash means to start to emit a flashlight.

Abstract: An electronic flash unit for emitting flashlight toward an object to be photographed in order that a camera may obtain proper exposure comprises flash means having a flash tube which emits flashlight, means for driving the flash tube in order that the flash tube may emit flashlight, and means for applying light to the interior of the flash tube prior to the driving means causing the flash tube to emit flashlight.

Abstract: An automatic control type electronic flash apparatus comprises means for emitting flashlight and flashlight emission stopping means. The stopping means receives the flashlight emitted by the flashlight emitting means and reflected by an object to be photographed and stops the emission of the flashlight by the flashlight emitting means when a quantity of the flashlight received reaches a predetermined value. The flash unit includes integrating means for integrating a current corresponding to the flashlight emitted by the flashlight emitting means in place of the flashlight reflected by the object and comparing means. The comparing means compares an integrated value from the integrating means with a reference value and generates a first output when the integrated value is smaller than the reference value and a second output when the integrated value is greater than the reference value. The flash unit includes indicating means for showing an over-exposure in response to the first output.

Abstract: In an electronic flash apparatus, electric power is alternately supplied by a same power source to the voltage elevating circuit for charging the main capacitor for flash emission and to other circuits provided in the flash unit or in the camera, such as a light emission control circuit for controlling the quantity of emitted light, an indicator circuit for indicating the completion of the charging of the main capacitor, an indicator circuit for indicating whether the light emission control is in operation, an alarm circuit for indicating an inadequate setting of the flash unit etc.

Abstract: In a flashlight emission system, apparatus for lighting a flash tube to illuminate an object and for controlling the quantity of emitted light from the flash tube, the apparatus being cooperative with a camera having structure for presetting ASA speed of film and aperture value of a taking lens prior to taking, there is provided a device for displaying the limit of object distance for providing an optimum exposure to the film comprising; apparatus for receiving information of the ASA speed and aperture value from the camera to make up first data corresponding to the received information; apparatus for making second data indicative of the limit of the quantity of emitted light controllable by the control apparatus; a device for calculating the limit of object distance from the first and second data and generating an output corresponding to the limit found out by the calculation; and apparatus for making a visual display of the limit of object distance in response to the output of the calculation device.

Abstract: A photographic system including a flash unit wirelessly controlled. The system comprises a controller interlocked with the photographic camera and a flash unit operable in response to the controller to illuminate object. Start and stop of flashing of the flash unit are controlled by control means in a particularly determined manner so as to prevent maloperation of the unit.

Abstract: In a camera having a flash unit for object and a data photographing device, the flash unit including means for detecting the light emission capable condition of a flash tube, the data photographing device having an optical system for imaging onto a film the light beam from information display means including a light source, there are provided drive means for turning on the light source for the data photographing device in synchronism with the output of the detecting means of the flash unit, and means for directing the light from the light source to the outside of the camera so that said light can be observed.

Abstract: A data recording device for a camera comprises a time signal generator for generating time-sequential time signals, display means changing the content of display in response to said time signal, a recording signal generator for generating a recording signal of a determined duration for causing the exposure of the display of said display means onto a photographic film and delay means for delaying the entry of said time signal into said display means until the termination of said recording signal in case said time signal is released during the continuation of said recording signal.

Abstract: A distance information judging circuit for focus detecting apparatus comprises memory means for storing a distance information signal obtained from the focus detecting apparatus for each scan of an optical system,, and coincidence signal generating means adapted for comparing the distance information signal obtained from the focus detecting apparatus in a succeeding scan of the optical system with the distance information signal stored in the memory means and for generating a coincidence signal when the distance information signals coincide each other.