Canon CLC 1120 Service Manual page 196

CHAPTER 6 IMAGE FORMATION SYSTEM
d. Flow of Control Using the Black Toner Concentration Sensor at Power-On and
Its Related Detail Code
Flow at power-on
1. Turning on the
power switch
2. Detecting dirt on
window
2.1Reading SGNK-D
2.2Making a
comparison and
computation
6-44
COPYRIGHT © 1999 CANON INC.
Flow of operation
(during initial rotation)
Black tone sensor LED
on; uses PS1 and PS2 to
check light; converts
light into voltage.
Compares 'SGNK-D' and
'REF-D' effective at time
of initial setting and
'SGNK-D' and 'REF-D'
read in 2.1 to compute
the window soiling
correction value for the
black toner sensor.
Photosensitive drum
Photosensor (PS1)
figure 6-411
CANON CLC1120/1130/1150 REV.0 MAR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Detail code
0465 The level of soiling of the
0475 window is 130 or higher.
The level of soiling of the
widow is 70 or less.
Black toner
concentration sensor
Photosensor (PS2)
Item of detection