Measuring The Concentration Of Color Toner On The Developing Cylinder Assembly - Canon CLC 1120 Service Manual

CHAPTER 6 IMAGE FORMATION SYSTEM
2. Measuring the Concentration of Color Toner on the Developing Cylinder
Assembly
The following shows the flow of operations used to measure and control the concentration of
color toner on the developing cylinder assembly:
Photo diode for
generation of
reference signal
6-32
COPYRIGHT © 1999 CANON INC.
Determines the initial developer concentration signal
(SGNL-M/C/Y) and initial reference signal (REF-M/C/Y)
(at time of installation, replacement of developer,
replacement of toner concentration sensor)
Copy Start key ON
Developing bias ON, developing cylinder ON (rotates)
LED ON (shines on developing cylinder)
Meaures the concentration of developer during copying
operation (SGNL-M/C/Y) and for reference (REF-M/C/Y)
during copying operation
Compares the initial data and the copy data to
compute the change in toner concentration.
Developing cylinder
LED
Reflecting
mirror
Figure 6-403
CANON CLC1120/1130/1150 REV.0 MAR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Photodiode for
measurement of
reflected light
X-SGNL
XLAON
X-REF
(M, C, Y into X)
DC driver PCB
RAM
SGNL initial
value
REF initial value
Rate of
amplification