Abstract: A strobe device includes: a battery case configured to hold a plurality of batteries; a main capacitor charged by the batteries; a flash discharge tube to which a voltage is applied by the main capacitor; a voltage detecting unit configured to detect a voltage of each of the batteries, respectively; and a charging control unit configured to control charging of the main capacitor such that the main capacitor is charged with a first electric current that is suitable for lithium batteries in a case where a total voltage of the batteries detected by the voltage detecting unit is more than a prescribed first value, and control charging of the main capacitor such that the main capacitor is charged with a second electric current that is greater than the first electric current in a case where the total voltage is equal to or less than the first value.

Abstract: A lighting control circuit for a flash discharge tube can include an IGBT drive circuit and a timer circuit provided in parallel to each other to output a drive voltage to an IGBT device. An OR circuit can be provided for delivering an output to the IGBT device based on the outputs from both the IGBT driver circuit and the timer circuit. Therefore, the IGBT device can be subject to a voltage output obtained by performing the logical sum of the outputs from the IGBT drive circuit and the timer circuit. This can ensure a necessary and sufficient voltage to the gate of the IGBT device.

Abstract: A uniform flash-emission controller which controls an intensity of a light emission of a flashtube, the uniform flash-emission controller includes an IGBT which causes the flashtube to emit a rapid series of short flash pulses; an IGBT controller which switches the IGBT ON and OFF so as to maintain the intensity at a substantially constant level; and a latch for holding an ON state and an OFF state of the IGBT until a predetermined period of time elapses from a time the IGBT controller switches the IGBT ON and OFF, respectively.

Abstract: An electronic flash device includes: a flash light emission circuit that performs a flash light emission; a light emission control circuit that supplies power for light emission to the flash light emission circuit in response to an input of a light emission start signal and cuts off the power to the flash light emission circuit in response to an input of a light emission stop signal; and a protective circuit that detects a state that will induce power supply to the flash light emission circuit in response to an anomalous signal based upon a circuit operation of the light emission control circuit and prevents the power supply to the flash light emission circuit.

Abstract: A lens-fitted film unit incorporating a strobe device, comprises: a main body; a photographic film loaded in advance in said main body; a shutter; a photographic lens; and a strobe circuit included in said strobe device, said strobe circuit comprising, a boosting-up circuit including a DC power source, an oscillation transistor, an oscillation transformer having a primary winding and a secondary winding, and a rectifying element for rectifying an electronic current induced by said oscillation transformer, an oscillation controlling circuit for controlling a base potential of said oscillation transistor, and a strobe lighting circuit including a main-capacitor charged by said electronic current rectified by said rectifying element, and a strobe-lighting tube driven by an electronic charge charged in said main-capacitor, wherein a collector and an emitter of said oscillation transistor are serially coupled between said DC power source and said primary winding of said oscillation transformer, and a base of said

Abstract: The present invention relates to an electronic flash device which, even if the charged voltage of a main capacitor is low, can securely effect a trigger operation by making a trigger voltage higher than the charged voltage of the main capacitor.

Abstract: A flash device comprising a power source; a main capacitor adapted to be charged by the power source; a flash firing unit operable to consume charge stored in the main capacitor to emit a flash light; a switching unit disposed in a discharge loop for the main capacitor through the flash firing unit; a trigger circuit for exciting the flash firing unit in response to a flash firing command; a pulse output unit, which is operable to output some kinds of pulses, the duty factors of the pulses being different from each other, for inputting a selecting command and For outputting one of the pulses in accordance with the selecting command; and a control unit for causing the switching unit to be switched on and off repeatedly in response to the pulse outputted from the pulse output unit.

Abstract: An electronic flashing device includes a booster circuit for boosting a power supply voltage to a predetermined voltage, a main capacitor charged via the booster circuit, a light emission tube for emitting light according to a charge charged on the main capacitor, a semiconductor element connected in series with the light emission tube, and including a thyristor element and a MOSFET which are cascade-connected to each other, and are formed on a single chip, a trigger circuit for applying a trigger voltage to the light emission tube in response to a light emission start signal for causing the light emission tube to start light emission, a gate voltage applying circuit for applying a voltage to the gate of the semiconductor element in response to the light emission start signal, and a gate voltage disappearing circuit for causing the voltage at the gate of the semiconductor element to disappear in response to a light emission stop signal for causing the light emission tube to stop light emission.

Abstract: A power supply circuit includes a booster circuit for boosting an output voltage from a power supply battery to predetermined positive and negative voltages, respectively. A main capacitor is charged by the predetermined positive or negative voltage boosted by the power supply circuit. In a discharge tube, a discharge current flows on the basis of the charge built up on the main capacitor, so that flash light emission is performed. A MOS controlled thyristor (MCT) is inserted in the loop of the discharge current from the main capacitor. A control circuit ON/OFF-controls the MCT by selectively applying the predetermined positive or negative voltage from the power supply circuit to the gate terminal of the MCT.

Abstract: The oscillating switching element of step-up transformer comprises a dedicated high-frequency FET and is placed between center tap of the primary coil and the ground of the primary circuit. Terminal of the primary coil on the side of the ground is connected to the connection point between xenon tube and the light emission controlling switching element, i.e., an IGBT, via diode. Charge voltage of main capacitor is detected by voltage detection circuit, and when charge voltage is below threshold voltage, controller drives the IGBT at a low frequency, while when charge voltage has exceeded threshold voltage, it drives the FET at a high frequency to charge main capacitor. The charging of main capacitor is made faster and more efficient by changing the switching frequency and by switching the switching element between the IGBT and the FET as charge voltage increases.

Abstract: With an electronic flash device that utilizes an IGBT, circuit construction can be simplified using a single condenser as both the trigger condenser of a trigger circuit and the voltage doubling condenser. In addition, because the recharging of the multi-purpose condenser is accomplished through the radiation current that flows through the light emitting tube directly after the collector/emitter gap of the IGBT becomes nonconductive, the device allows flash radiations to be repeated at high speed.