Developing device and developer supply device for the same

摘要

A developing device and a toner supply device for a color copier and others. A toner supply conduit adapted to transport fresh toner from the toner supply device is disposed in a developer chamber of the developing device. The wall of the toner supply conduit is perforated to form inlet openings and outlet openings for a developer which is stored in the developer chamber and contains toner and carrier. The inlet openings of the conduit are located in the vicinity of a predetermined position where the developer is to be separated from a developer conveying member. Provided in the toner supply conduit is a transport member for mixing and transporting the fresh toner and the developer which is introduced through the inlet openings. At least a part of the transport member is made of a magnetic material, and at least a part of the magnetic part is situated within the reach of a magnetic force of a magnet which forms a part of the developer conveying member. The toner supply device comrises a toner tank, and a feed member for feeding the fresh toner out of the toner tank. The frequency of operation of at least one of the toner feed member and other operable members which are associated with the toner feed member is counted. The end of toner is displayed when the frequency counted reaches a predetermined one representative of a decrease of toner in the toner tank to zero or to below a predetermined amount.