Abstract: A transfer type electrophotographic copying apparatus of scanning system compact in size and efficient in copying operation and maintenance which is equipped with an improved copying sequence control arrangement through which an exposure lamp for an original to be copied, corona charger for a photoreceptor and also copy paper feeding device are adapted to be simultaneously turned ON by signal from one detecting means, while the number of detecting switches for operating various components of the copying apparatus in association with the copying operation is reduced to minimum by disposing such components at predetermined distances from each other, with the circuit for the control being also extremely simplified.

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: Carbon black and liquid rubber are blended to form a dispersion by mixing 60 to 150 parts by weight of the carbon black with 100 parts by weight of the liquid rubber to form an initial dispersion of the carbon black in the liquid rubber and diluting the dispersion with additional liquid rubber to prepare a composition having the required carbon black content.

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.

Abstract: A printing paper cutting device for use in an electrophotographic copying apparatus employing a roll of printing paper which comprises a control device for cut length associated with a paper feeding and cutting device. The paper feeding and cutting device includes a pair of first rollers, a pair of second rollers, a cutting device disposed between the first and the second rollers and a pair of third rollers, and is adapted to cut the printing paper in a stretched state between the first and the second rollers with a loop of printing paper formed between the second and the third rollers, while the control device has contraction scale marks corresponding to the length of the original to be copied for compact size and easy operation of the cutting device.

Abstract: In a transfer type electrophotographic copying apparatus which comprises a reciprocating platform for supporting an original to be copied, a rotatable photoreceptor drum of a small diameter, and processing devices of small size disposed around the photoreceptor drum for compact size of the copying apparatus, an improved transfer device and a transferred image disturbance prevention device are further included for efficient copying operations.

Abstract: A transfer type electrophotographic copying apparatus with a reciprocating platform to place an original to be copied thereon, which comprises a rotatable photoreceptor drum of a small diameter, and processing devices of small size disposed around the photoreceptor drum with minimum spaces necessary between the processing devices, so that the size and weight of the copying apparatus can be reduced to a large extent. The housing of the apparatus can be divided into an upper frame and a lower frame with the upper frame pivotally connected to the lower frame for easy access to the internal mechanisms in maintenance and replacing of the parts.