Drum Gear Position Sensors - Ricoh B202 Service Manual

PHOTOCONDUCTOR UNIT

6.7.3 DRUM GEAR POSITION SENSORS

[E]
[D]
[C]
[B]
[A]
[F]
[G]
[H]
[I]
B178D539.WMF
Mechanism
The machine uses these sensors to detect if the drum motors rotate. SC440 shows
when it detects that the drum motor is not moving. These sensors also help the
machine to initialize the relative positions of the gears when the main switch is
turned on, and during initializing. This prevents phase fluctuation between
printouts.
There is an interrupter [E] on each of the black [D] and yellow [C] drum gears. The
drum gear position sensors [F][G] detect the positions of these interrupters
respectively. The sensors check that the two interrupters are parallel. This
mechanism makes sure that output quality does not vary. The cyan [B] and
magenta [A] drum gears operate with the yellow drum gear because these three
drum gears are linked through other gears [H][I].
In the ready status, the two interrupters stay in a parallel position. If they are not in
a parallel position (shown in the illustration), the machine adjusts the position of the
black drum gear.
The relative positions of the gears are adjusted every 30 jobs.
SM 6-51 B202/B178/B180