Self-timer circuit and self timer-device incorporating said self timer circuit

Claim 2

A self-timer device for releasing a shutter of a camera comprising a time-constant circuit comprising resistor means having a voltage division point and capacitor, a first switching circuit for switching between two states in response to a voltage across said capacitor, the output terminal of said first switching circuit being coupled to an electromagnet means for releasing the shutter of the camera, and a display circuit means whose input terminal is connected to the voltage division point of said resistor means, said display circuit means comprising a second switching circuit whose input terminal is connected to said voltage division point of said resistor means, and display means connected to the output terminal of said second switching circuit, whereby said display means may give the warning signal before said electromagnet means is energized to release the shutter.

Claim 3

A self-timer device as set forth in claim 1 wherein said resistor means comprises a variable resistor and a divided voltage is derived from its sliding arm.

Claim 4

A self-timer device as set forth in claim 1 wherein said display circuit further comprises an oscillator whose operation is controlled by the output of said second switching circuit so that display means flashes.

Claim 5

A self-timer device as set forth in claim 1 wherein said switching circuit comprises a differential amplifier one of the input terminals of which is coupled to said capacitor and the other terminal of which is coupled to said resistor means, whereby the self-timer time may be set to a desired time in response to the resistance of said resistor means having a voltage division point.

Claim 6

A camera incorporating a self-timer device foR releasing a shutter of said camera comprising resistor means and a photoelectric cell for measuring the brightness of a subject, switching means for selecting either of said resistor means or said photoelectric cell, a capacitor coupled to said switching means for setting a time, a first switching circuit whose input terminal is connected to said resistor means and whose output terminal is connected to electromagnet means for releasing the shutter of said camera, a second switching circuit means whose input terminal is connected to said photoelectric cell and whose output terminal is connected to control means which controls the closure of said shutter, and a display circuit means whose input terminal is connected to the voltage division point of said resistor means and which comprises a third switching circuit whose input is connected to the voltage division point of said resistor means, and display means connected to the output terminal of said third switching circuit.

Claim 7

A camera incorporating a self-timer device foR releasing a shutter of said camera comprising resistor means and a photoelectric cell for measuring the brightness of a subject, switching means for selecting either of said resistor means or said photoelectric cell, a capacitor coupled to said switching means for setting a time, a first switching circuit whose input terminal is connected to said resistor means and whose output terminal is connected to electromagnet means for releasing the shutter of said camera, a second switching circuit means whose input terminal is connected to said photoelectric cell and whose output terminal is connected to control means which controls the closure of said shutter, and a display circuit means whose input terminal is connected to the voltage division point of said resistor means and which comprises a third switching circuit whose input is connected to the voltage division point of said resistor means, and display means connected to the output terminal of said third switching circuit.