Abstract: An electrophotographic copying apparatus is equipped with an indication device for the maximum area to be covered by copying, i.e. the area available for copying or copying coverage. The copying coverage indication device which includes a micro-computer is arranged to indicate the area to be covered by copying according to the sizes of copy paper sheets and copying magnifications for preventing use of copy paper sheets of unnecessarily large or small sizes, and is capable of warning an operator of the necessity for exchanging sizes of copy paper sheets.

Abstract: A lighting device in which an amount of light emitted by a lamp is detected by a light receiving element for controlling the input voltage of the lamp commensurate with the detected amount of light. By utilizing a pre-illumination system in conjunction with the lighting device, it is possible to improve the sensitivity characteristics of the light receiving element as the lamp is being charged up to a desired level of illuminescence and to prevent the input of an excessive voltage to the lamp.

Abstract: A copying apparatus which is equipped with a scanning system control device including means for judging sizes of copy paper sheets employed, means for detecting copying magnifications, and means for controlling movement of the scanning system of the copying apparatus so as to correspond to the area available for copying or copying coverage to be determined by the judged size and detected copying magnification. The movement of the scanning system is not controlled by the size of the original or copy paper sheet itself, but is regulated to correspond to the area available for the copying on an original platform to be determined by the copy paper size and copying magnification.

Abstract: The power regulator of the present disclosure is operated by a source of D.C. power for controlling the A.C. power to be supplied to an exposing device and to a fixing device. It comprises a first circuit for operating the exposing device, a second circuit for operating the fixing device, a switching circuit for alternately operating the first and second circuits and a third circuit for operating the fixing device independently of the operation of the switching circuit so that the fixing device may be warmed up by the operation of third circuit during the operation of the exposing device.

Abstract: The present invention is an electrophotographic copying apparatus which includes a group of switches disposed along the path of the copy paper. These switches are so arranged as to control the functions of corona charging, exposure and aligning the forward edge of the image formed on the photoreceptor with the leading edge of the copy paper, while the starting of the transfer device and the function of the copy paper separation device are controlled through a control cam which is driven by actuating signals produced by one of these switches. Since the developing and transfer functions are arranged to be suspended by a drum cam rotating as one unit with the photoreceptor drum, the possibility of copy paper jamming is decreased to a large extent through reduction of the number of switches employed, while undesirable developing and transfer at the slot portion or seam portion of the photoreceptor are advantageously eliminated.

Abstract: Presetting counter device for control of single or repeated actuation of a piece of equipment permits stopping of equipment action during continuous repeat action thereof if required, and always resets a display means for an indication of the number of times the device is required to be actuated to "1" when the equipment is thus stopped and after single or repeated actuation of the equipment, whereby manual resetting action by a user is unnecessary. As the device requires manual actuation only of a resetting switch, an initial count means for specifying a required number of actions during actuation of the equipment, and a start switch, equipment control with the device is extremely simple.

Abstract: An electrophotographic copying apparatus incorporating therein an improved developing material supplying device which supplying device includes a copy paper detecting unit for detecting the length of the copy paper, an integrating circuit for integrating the length of the copy paper detected by the detecting unit and a supply tank driving unit which operates the supply tank to supply a concentrated developing material into the developing tank through a valve, upon receipt of a signal from the integrating circuit, by which arrangement, the concentrated developing material can be supplied to the developing tank every time after a predetermined length of the copy paper is fed through the developing tank.

Abstract: In operating an apparatus provided with a plurality of various component devices incorporated therein, it is necessary to provide some type of sequential controller when the plurality of the devices are required to be operated sequentially for predetermined periods, independently of each other. The improved type of sequential controller of the present disclosure has a plurality of cam plates each of which is provided with switch units for controlling the operating periods of the various component devices, and which are rotated by a driving means, a lock claw for engaging with the cam plates and a controller for controlling the movement of the lock claw, so that the predetermined rotation of the cam plates controls the operating periods of the various devices.

Abstract: A temperature control device in which electric power to be supplied to a heating element is controlled correspondingly to pulse intervals applied to a switch circuit with the pulse intervals adapted to vary according to the temperature of the portion to be heated by the heating element, which temperature control device is further provided with a sensor for detecting the pulse intervals when the temperature of the portion to be heated has reached a predetermined level with the signal from the sensor being utilized as the signal for the completion of warming-up of the portion to be heated.

Abstract: In an electric safety switch circuit for use in apparatus having at least one safety switch for detecting at least one abnormal condition of the apparatus, switching elements are connected between a power source and the apparatus. The voltage of the main power source is transformed to a lower voltage and the switching elements are opened or closed by control circuitry in the low voltage circuit. The at least one safety switch is connected to the voltage transformer and the control circuitry such that the actuation of the at least one safety switch upon detection thereof of an abnormal condition actuates the control circuitry to open the switching elements and disconnect the apparatus from the power source.In one embodiment a primary switch is interconnected between the power source and the electric safety switch circuit, and in a modified embodiment the primary switch is connected in the electric safety switch circuit itself.