| 摘要 |
A charge and bias control system for a liquid-developer electrophotographic copier in which a sensing electrode is disposed in the developing station just upstream of the developing electrodes. Developer liquid fills the space between the sensing electrode and the photoconductor to provide a direct coupling between the two elements. The charge level is adjusted at the beginning of each copy cycle by supplying the control input for the charge-corona power supply with a ramp derived by periodically indexing a counter concurrently with the movement of the photoconductor. When the photoconductor surface potential, as measured by the sensing electrode, reaches a predetermined level, further indexing of the counter is inhibited. The same sensing electrode is used during the scanning phase of the copy cycle to regulate the biasing potential applied to the developing electrodes. Opposite-polarity cleaning potentials are applied to the developing electrodes between successive scans over respective time intervals which are staggered in accordance with the displacement of the developing electrodes along the path of movement of the photoconductor.
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