Oce 3121, Technical & Service Manual

Page: 249 / 908

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ed.1 05 Developing 503
2 The cleaner in the developing unit
Outline
The developing unit is locked mechanically by the locking levers on each of
the developing rails.
The drive from the main motor rotates the following:
■
the developing roller,
■
the stirring rod in the developing unit,
■
the rotary blade inside the drum cleaner.
The level of toner is detected via the toner absent signal (TEP), from the toner
level sensor (TS1) inside the developing unit
The waste toner is collected by the rotary blade. The waste toner sensor (PS10)
turns on when the waste container is full.
Detecting the level of toner
A toner sensor (TS1) of an oscillator type is provided to monitor the level of
toner. The sensor is located inside the developing unit.
When the level of toner in the unit is above a specific level, the output of the
toner sensor is ‘1’. When the toner falls below that level, the output of the toner
sensor is ‘0’.
When the developing clutch (CL4) is energised, the CPU on the DC control
PBA reads the output of the toner sensor. It then computes the period during
which the toner sensor output remained ON to issue a message to supply toner.