Apparatus for brush development including means for detecting toner in the toner bath and means for supplying toner to the toner bath

摘要

A developing apparatus is disclosed which has a toner bath with a magnetic toner placed therein, the toner being supplied via a developing role to a developing gap between an image carrying substance and the developing roll, and a toner supply bath for supplying the magnetic toner to the toner bath, a latent image formed on the image carrying substance being developed with the magnetic toner by means of a magnetic brush development. The developing apparatus has a detector member for generating a signal when the magnetic toner is absent in the toner bath, a drive member which responds to the signal generated from the detector member, and a magnetic field generating device driven by the drive member for magnetically shutting off a supply path provided between the toner supply bath and toner bath when the detector member generates no signal, but magnetically opening the supply path when the detector member generates the signal.