Electronic flash device


PURPOSE: To permit sure obtaining of a charging completion signal when a main capacitor is charged to a voltage at which a light emitting tube can emit light by providing a circuit means which outputs the charging completion signal when a charging stop signal is inputted thereto. CONSTITUTION: The charging voltage of the main capacitor 27 increases gradually and the current flowing to an element 18 for detecting the charging stop voltage increases to turn on a transistor (TR) 3 when on and off of a release button by a half push thereof are repeated without releasing the shutter of a camera. A TR 2 remains cut off at this time and an oscillation circuit A stops oscillating; therefore, even if the charging voltage of an electronic flash is sufficiently high, the current passing to an element 16 for detecting the charging completion voltage is interrupted and the output of a circuit 28 for detecting the charging completion signal goes to an 'L'. However, the element 18 is directly connected to the capacitor 27 and the output of a circuit 29 for detecting the charging stop signal goes to an 'H', then the output of an OR circuit 34 goes to an 'H' and the charging completion condition is surely decided by a circuit 32 for latching the charging completion signal. COPYRIGHT: (C)1988,JPO&Japio




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Patent Citations (2)

    Publication numberPublication dateAssigneeTitle
    JP-S5423523-AFebruary 22, 1979West Electric CoElectronic flash device having chargee voltage indicator for use in photography
    JP-S60143328-AJuly 29, 1985Ricoh Co LtdPower circuit of strobe incorporated camera

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Cited By (2)

    Publication numberPublication dateAssigneeTitle
    JP-H02105125-AApril 17, 1990Konica CorpStroboscope incorporated camera
    JP-H02193131-AJuly 30, 1990Canon IncFlashing device