Controlling Toner Level Detection - Canon GP335 Service Manual

CHAPTER 6 IMAGE FORMATION SYSTEM
C. Controlling Toner Level Detection
A toner sensor of a piezoelectric oscillation type (TS1) is mounted inside the developing
assembly to monitor the level of toner.
When toner exists inside the developing assembly, the output of the toner sensor goes '1'; when
the level of toner drops below a specific value, the output will go '0'.
The DC-CPU on the image processor PCB reads the output of the toner sensor while the
developing clutch (CL4) remains on. It then computes the 0's (most recent two cases) of the toner
sensor output, and indicates the Add Toner message in the touch panel as needed.
Toner absent level 1
If the most recent toner absent
periods add up to 10 sec or more,
Copying No
Fax receive Yes
Fax send Yes
Yes
Printer output
Check
Developing clutch (CL4)
Toner sensor (TS1)
6-20
NG
OK
(11 sec)
(9 sec)
5 sec
3 sec
6 sec
When the power switch is turned on/off,
recovery is made after stirring
the toner for 6 sec.
Figure 6-202
COPYRIGHT © 1999 CANON INC. CANON 405/335 REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Toner absent level 2
If the toner absent periods
add up to 80 sec or more,
No
Copying
Fax receive Yes
Fax output No
No
Printer output
OK
(7 sec)
82 sec
2 sec
When the power switch is turned on,
recovery is made after stirring
the toner for another 30 sec.
NG
(82 sec)