Developing Assembly/Drum Cleaner - Canon GP215 Service Manual

3. OPERATIONS AND TIMING
G. Developing Assembly/Drum Cleaner
1. Outline
The developing assembly is locked manually by operating the locking lever for each developing rail.
The developing cylinder, stirring rod in the developing assembly, and the feeding blade inside the drum
cleaner are rotated by the drive of the main motor.
The level of toner is detected in reference to the toner absent signal (TEP) from the toner level sensor
(TS1) inside the developing assembly.
The waste toner collected by the cleaning bale is collected inside the cleaner case, and the waste toner
sensor (PS10) turns on when the waste toner case becomes full.
2. Detecting the Level of Toner
A toner sensor (TS1) of an oscillator type is provided inside the developing assembly to monitor the
level of toner.
When the toner inside the developing assembly is more than a specific level, the output of the toner
sensor goes '1'. When the toner falls below a specific level, on the other hand, the output of the toner sen-
sor goes '0'.
The CPU on the DC controller PCB reads the output of the toner sensor while the developing clutch
(CL4) remains ON. It then computes the period during which the toner sensor output remained ON to issue
a message to initiate toner supply. See Table 3-502 and Figure 3-510 for how this is done.
Result
Toner absent level 1 is
assumed if the sum of the peri-
ods in which toner is absent is
20 sec or more in the past two
checks.
Toner absent level 2 is
assumed if the sum of the peri-
ods in which toner is absent is
160 sec or more.
3–70
COPYRIGHT © 1996 CANON INC.
Operation
Toner supply is initiated, but
copying operation is prohibited.
(FAX reception and printer out-
put are possible.)
Toner supply is initiated, but
copying operation, FAX output,
and printer operation are all
prohibited.
Table 3-502
CANON GP215/200 REV.0 JULY 1996 PRINTED IN JAPAN (IMPRIME AU JAPON)
Resetting
Resetting occurs when toner
has been stirred by keeping the
developing clutch ON for 6 sec
after the control panel power
switch was tuned ON or the
front door was opened and
closed.
Resetting occurs when toner
has been stirred after keeping
the developing clutch ON for 30
sec and detecting the presence
of toner after the control panel
power switch was turned ON or
the front door was opened and
closed.