摘要 |
An automatic toner supplying device applicable to an developing apparatus for use in an electrophotographic copying machine which is based on the physical property that the amount of toner powder consumed for developing is proportional to the potential variations of magnetic brush bristles which contact the photoreceptor surface during rotation of a photoreceptor drum and a developing roller with the potential variations utilized as a toner replenishing signal for applying a bias voltage corresponding to the toner replenishing signal, through an electrical control unit, to the brush bristles formed on a toner supply roller rotatably disposed in a toner supply tank.
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