Start
1) Because the grid potential is at a low level, the drum poten-
tial is at about –400V. (Carrier may not be attracted though
the carrier is pulled towards the drum by the electrostatic
force of –400V.
2) Developing bias ( –400V) is applied when the photoconduc-
tor potential is switched from LOW to HIGH.
3) Once developing bias (–400V) is applied and the photo con-
ductor potential rises to HIGH, toner will not be attracted to
the drum.
Stop
The reverse sequence takes place.
Retaining developing bias at an abnormal occurrence
Function
The developing bias will be lost if the power supply was
removed during print process. In this event, the drum potential
slightly abates and the carrier makes deposits on the drum be-
cause of strong static power. To prevent this, the machine in-
corporates a function to retain the developing bias for a certain
period and decrease the voltage gradually against possible
power loss.
Basic function
Normally, the developing bias voltage is retained for a certain
time before the drum comes to a complete stop if the machine
should stop before completing the normal print cycle. The
developing bias can be added before resuming the operation
after an abnormal interruption. Therfore, carrier will not make a
deposit on the drum surface.
AL-1000/1010
6-4
