Abstract: An electric power supply control circuit is designed to interrupt the power supply to at least either one of a calculating circuit or an analog-digital converting circuit during the interval between two succeeding sample operations in order to reduce power consumption.

Abstract: A motor drive apparatus comprises phase switches adapted to assume a first state upon shutter release of a camera, to cause the film advancement to be started upon receipt of an exposure completion signal from the camera in the first state and to assume a second state upon completion of the film advancement to enable succeeding shutter release. A timer circuit is adapted to start counting time upon receipt of the exposure completion signal from the camera and to release a timer signal upon completion of counting after the lapse of a predetermined period. Release apparatus is adapted to generate a release signal during the second state of the phase switches and upon release of the timer signal from the timer circuit thereby causing the shutter release of camera to be started. The motor drive apparatus can avoid the influence of variation in the film advancing period in continuous photographing and achieve an always constant actual interval.

Abstract: A metering device comprises a photoelectric converter circuit for generating a first voltage corresponding to the brightness of a subject to be photographed. The converter circuit includes a photoelectric converter element and a first conductor element for logarithmically converting the output of the photoelectric converter element. The device further comprises a voltage generating circuit including a second semiconductor element and a current source for flowing a current proportional to an absolute temperature to a resistor connected in series to the second semiconductor element. The voltage generating circuit is effective to generate a second voltage comprising the sum of the voltages generated in the resistor and the second conductor element. The difference beween the first and the second voltage is put out by a differential amplifier.

Abstract: A drive circuit for pulse synchronized motor has a circuit for generating an output signal corresponding to the frequency of synchronizing pulse signals and a voltage setting circuit for automatically setting, according to the output of the output circuit, the voltage to be applied to the motor within a synchronizable voltage range of frequency of the synchronizing pulse signals for synchronizing the motor. The drive circuit is capable of automatically maintaining synchronized state over a wide frequency range.

Abstract: An electromagnetic trigger device in a motor-driven camera capable of selection of continuous single-frame or time exposure mode. A latching lever latches a shutter driving mechanism in a shutter closed position in which a shutter is completely closed and in a shutter open position in which the shutter is fully opened. A preventing member prevents the latching lever from latching the shutter driving mechanism in the shutter open position when the continuous or single-frame exposure mode is selected.

Abstract: A booster circuit applies a high voltage to a load for starting or energizing the load which is operated at a steady voltage once it has started. The booster circuit comprises a power source, a diode or a resistor provided in forward direction with respect to the power source, a first switch and a load. The booster circuit further comprises a capacitor which is charged by said power source through said diode when said first switch is opened and a second switch which is actuated upon closure of said first switch to connect said capacitor in parallel to said diode so that said diode is reversely biased by said capacitor.

Abstract: This invention relates to an electromagnetic trigger device in a motor-driven camera for effecting bulb exposure in which the shutter is kept open during depression of the shutter release button. By depression of the shutter release button, discharge current from a first capacitor directly or indirectly energizes a electromagnet to drive a shutter driving mechanism. A latching lever stops the shutter driving mechanism in an open shutter position. By release of the button, discharge current from a second capacitor directly or indirectly energizes the electromagnet to drive the shutter driving mechanism. The latching lever stops the shutter driving mechanism in a closed shutter position, thus accomplishing the bulb exposure.

Abstract: An electromagnetic trigger device for use with camera capable of automatic time exposure, comprises: a power supply; a motor; a trigger switch; shutter driving means driven by said motor for driving a shutter and movable between a fully closed position and a fully open position, said shutter driving means fully opening the shutter when it is at the fully open position and fully closing the shutter when it is at the fully closing position; engaging means movable between a latching position and a non-latching position, said engaging means being adapted, when moved to said latching position, to latch said shutter driving means which occupies one of the fully open and closing positions; a motor switch which is closed for electrically connecting said motor to said power supply, when said engaging means is in said non-latching position; a starting coil for attracting said engaging means, when energized, to move said engaging means to said non-latching position; a switching circuit for connecting said starting coil

Abstract: In an electromagnetic trigger device in a camera capable of effecting time photography, and having a trigger switch, a power source and a motor for driving a shutter driving mechanism, there is provided a restraining lever movable between a restraining position and a non-restraining position. The lever, when in the restraining position, restrains the shutter driving mechanism in fully closed shutter position. A motor switch is adapted to be closed to energize the motor when the restraining lever is in the non-restraining position. A phase switch is parallel-connected to the motor switch and operatively associated with the shutter driving mechanism to be opened in the fully open and the fully closed position of the shutter. An actuating coil is responsive to closing of the trigger switch to be connected to the power source for a predetermined time and thereby energized to attract the restraining lever to the non-restraining position.

Abstract: Remote control apparatus for cameras having an automatic exposure control circuit and a mechanaism for operating the shutter and advancing the film in the camera comprises a first circuit responsive to a remotely generated photography signal for generating a first control signal to actuate the automatic exposure circuit and a delay circuit for generating a second control signal delayed relative to the first control signal to actuate the shutter-operating and film-advancing mechanism.

Abstract: A capacitor-energized electromagnetic trigger device controls the energization of a camera motor which drives a film transport and shutter mechanism. For one-frame photography the motor is de-energized after a predetermined number of revolutions and then the transport and shutter mechanism is immobilized by a restraining device. For continuous photography the motor continues to operate and the restraining device is maintained ineffective. For repetitive one-frame photography, the capacitor is recharged after a one-frame cycle and the cycle is repeated. Embodiments are disclosed having different types of switching circuits, including different arrangements of transistor switches, SCR switches, mode selection switches, reset switches, and starting and holding coils.

Abstract: For the purpose of assuring the holding latching relay in a nonconductive situation whenever an operator turns off a power switch, this invention provides a circuit for generating a signal for a predetermined time interval after the power switch is opened. The circuit includes a power switch, a capacitor charge only when the power switch is closed, a transistor and means for applying a terminal voltage of the capacitor to the transistor in order to render it conductive when the power switch is opened. A rectifier may be provided to prevent a reverse current and the capacitor maybe charged through the rectifier.