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The RAM on the DC controller PCB keeps count of copies being made; when it has
detected the hopper toner level detection signal (
=1) for 1 sec or more, it will assume
the presence of toner, thereby cleaning the counter and turning off the Add Toner
message on the control panel.
Reference:
The inside of both the developing assembly and the hopper assembly is each
equipped with a piezoelectric oscillator.
In the absence of toner, the oscillator oscillates at several kHz, and the output of
the sensor goes ‘0’. In the presence of toner, on the other hand, the weight of the
toner stops the oscillation, and the output of the sensor goes ‘1’.
Figure 4-203
If the developing assembly is not set inside the copier, do not install the developing
assembly locking assembly. Otherwise, the toner collecting in the path from the
hopper to the developing assembly can pour out because of the vibrations caused
by inspection/repair work.
AMP
Piezoelectric oscillator
Integration
circuit
Output
TEP
TEP
COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 4 IMAGE FORMATION SYSTEM
4-31
Caution: