Abstract: A detecting device for detecting when the amount of toner in a dual component developing material is less than a predetermined level includes a hopper for supplying the toner, a stirring roller for stirring a carrier and the toner from the hopper, and a detector for detecting the amount of developing material provided near the stirring roller to mix the toner supplied from the hopper with the carrier. A discriminator discriminates an output signal from the detector for a predetermined interval during the rotational period of the stirring roller. An indicating element operates in response to the output signal from the discriminator to indicate when the amount of the toner in the developing material is less than the predetermined level. Since it is indicated when the toner in the developing material is less than the predetermined level, the toner is supplied according to such indication, and therefore, an undesirable deterioration of copy density is prevented.

Abstract: The present invention relates to a developing material supplying control device for an electrostatic copying apparatus which includes an oscillator circuit composed of an oscillation coil provided along a toner supplying passage, a timer, a counter for counting the output signal from the oscillation circuit at every interval predetermined by the timer to supply a discriminating output signal when the counted value is equal to a predetermined value for each of the intervals. A toner supply acts in response to the discriminating output signal from the counter for supplying toner to the toner supplying passage. Since this invention employs the oscillation coil and does not employ a mechanical switch having a movable contact for detecting toner in the toner supplying passage, the toner supplying operation is achieved precisely.

Abstract: A supporting mechanism of a document cover lid to be used for a copying apparatus includes a base of a supporting member mounted to the upper portion of an apparatus housing so as to swing about a horizontal axis. A positioning member is mounted on one of either the apparatus housing or the supporting member has a first frictional surface which is a circular periphery in a vertical plane with respect to the horizontal axis. A contact member is mounted on the other of either the apparatus housing or the supporting member and, has a second frictional surface, which is a circular periphery in a vertical plane with respect to the horizontal axis and is elastically pushed against the first frictional surface. By this mechanism, it is possible to support the document cover lid in an opened position upwardly at an angle sufficient to replace an original document.

Abstract: A transfer type electrostatic copying apparatus in which the area of a photosensitive member cleaned by a cleaning device reaches an exposure zone simultaneously or prior to the arrival of a movable portion of an optical system or an original carrier at an exposure starting position from a home position thereof. This results in clear and definite copied images being obtained. At the earlier stage at which the movable portion of the optical system or the original carrier starts moving, the photosensitive member is subjected to the cleaning process, and then the exposure process is effected when the movable portion or the original carrier is running stably. Thus, the electrostatic latent image obtained by the exposure are clear and definite and free from undesirable blurs. The photosensitive member is a rotary drum having bosses connected at opposite axial ends thereof which are removably mounted in holder members on the sidewalls of the copying apparatus.

Abstract: A developing device in an electrostatic copying apparatus. The developing device includes a developer container, a developer applicator for holding on its surface a pair of a developer present in the developer container and applying toner particles to a latent electrostatic image to be developed, and a toner particle dispenser for dispensing toner particles therein to the developer container. The toner particle dispenser is controlled such that it performs a toner particle dispensing action in response to the performance of a copying process by the electrostatic copying apparatus. The developing device is provided with a device for inhibiting the dispensing of toner particles which makes the toner particle dispenser unable to start a toner particle dispensing action when a sufficient amount of the developer is present in the developer container.

Abstract: An electrostatic photographic copying machine includes a device for automatically exchanging used master paper with fresh master paper on a master holding body, and for indicating when such an exchange should be initiated. The machine includes an apparatus for cleaning the fixing roller, an apparatus for adjusting the amount of toner supplied to the developer, a transfer device whereby improper discharge is prevented, a transfer paper jam detector, and a device for improved mixing of developer.