Abstract: An electric camera shutter of the type having a digital recording and reproducing system has a self-timer mode and has a counter circuit for counting and memorizing pulses produced by a pulse generator. In one mode of operation, the exposure time is controlled in accordance with the memorized content of the counter circuit and when in the self-timer mode, the output of the counter circuit controls the energization of a self-timer operation indicator circuit which indicates operation in the self-timer mode.

Abstract: A digital exposure time control circuit including a standard pulse generating circuit for developing standard rate pulses which are applied under control of a brightness-time conversion circuit to a dividing circuit, and subsequently counted in a reversible counter operating in a counting mode. The number of standard pulses counted are controlled by the brightness-time conversion circuit to be proportional to an exposure time, and the counted pulses are subsequently read-out from the counter to control exposure time. The exposure time control circuit also includes a self-timer control circuit which is responsive to a predetermined number of counted pulses to clear the reversible counter, and enable the brightness-time conversion circuit when the number of counted pulses exceeds the predetermined number in order to develop a delay time, determined by the predetermined number of pulses to which the self-timer is responsive, before the start of counting the pulses for controlling exposure time.

Abstract: An alarming device for a clock comprises a manual selector for setting the desired alarm time. An alarm time setting detecting mechanism coacts with the rotationally driven time wheels of the clock for detecting the preset alarm time and thereafter actuates an audible alarm. An alarm time indicating mechanism provides a visual indication of the preset alarm time and includes a notifying mechanism which provides a visual indication indicative of the operative or inoperative state of the alarming device thereby notifying the user as to whether or not the device is set to detect an alarm time. The notifying mechanism comprises ON and OFF indicia which may be selectively illuminated or which may be selectively covered by a masking plate to provide the visual indication.

Abstract: An alarming device for a clock comprises a rotationally driven minute time wheel having plural sets of shift teeth, a rotatable 10-minutes time wheel which intermittently meshes with the shift teeth of the minute time wheel to be driven thereby, and a rotatable hour time wheel which intermittently meshes with the 10-minutes time wheel and is driven thereby. First and second detection devices respectively detect when the 10-minutes and hour time wheels are in predetermined angular positions, and setting means enables setting of the detection devices in predetermined positions. An audible alarm is rendered operative and provides an audible alarm only when the 10-minutes time wheel and the hour time wheel have respectively conformed in phase with said first and second detection devices thereby providing notification of the alarm time.

Abstract: An electronic camera shutter control circuit having an indicator for indicating when the camera shutter is open. A circuit responsive to a control signal controls a current flow through an electromagnet which is energized during the opening of the camera shutter to prevent the shutter release mechanism from closing the shutters. An indicating element indicates that current is flowing through the electromagnet and therefore indicates that the shutter is open. A control circuit having a photoresponsive element develops a control signal determined by the brightness of the scene to be photograhed and applies the control signal to the circuit responsive to the control signal. The control circuit includes a capacitor which is charged at a rate determined by the conductivity of the photoresponsive element which varies according to the light sensed.

Abstract: An exposure time control circuit for a camera shutter having a light-responsive element that controls charging of a capacitor as a function of the intensity of the light from a scene to be photographed. The charge of the capacitor at a certain level activates a switching circuit that initiates closing of the camera shutter. A light-intensity indicating circuit is directly connected to the light-responsive element for indicating the intensity of the light received from a scene to be photographed so that the camera shutter speed may be set accordingly. Photographic exposure and light readings are taken independently with control switches that need not make use of a change-over switch for connecting and disconnecting the light-intensity indicating circuit to the light-responsive element.

Abstract: An electric shutter with a positive motion device that insures positive action of the shutter. The shutter has a depressable release member that is restored by a spring when pressure thereon is released so that the release member is reset when the shutter is opened. When the shutter is cocked the mechanical positive motion device is mechanically releasably locked maintaining the shutter blade or blades against biasing springs. When the release member is depressed the shutter is opened and an electromagnet of an exposure control circuit is energized and an attractable lever in the positive motion device is held attracted by the energized electromagnet releasably controlling the release of members that release the shutter blade or blades for actuation to a shutter-closing position. A mechanical locking member in conjunction with a press lever in the positive control device positively locks the attractable lever in the same position as when attracted when the shutter is cocked.

Abstract: An electric shutter having a shutter release stop device that detects the absence of cocking of the shutter and that an electromagnet in the exposure control circuit of the shutter is not properly energized either because the battery is ineffective because it is expended or improperly connected in the circuit or not in the circuit. Detecting means initiates the action of a lock lever or bar that engages the camera shutter release lever and locks it so that it cannot be completely depressed for taking of an exposure. The taking of a photographic exposure is accordingly precluded and the waste of power and film is avoided.