Canon CP660 Service Manual page 126

CHAPTER 4 IMAGE FORMATION SYSTEM
2. Color Developing Bias Generation Circuit
This circuit is controlled by three signals (Figure 4-605) from the DC controller PCB,
and generates the color developing DC bias and color developing AC bias for application
to the color developing cylinder.
The color developing AC bias drive signal is used to turn on and off the AC bias
applied to the color developing cylinder, while the color developing DC bias drive signal
is used to turn on and off the DC bias applied to the color developing cylinder.
The color developing bias level control signal, on the other hand, is used to switch the
levels of the color developing DC bias for image areas.
DC controller
PCB
Note:
The color developing DC bias level for image areas is varied in response to the den-
sity command from the printer board*
rection control (p. 4-21).
1
* Rear controller PCB (when making prints with the reader unit installed).
4-28
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Color developing DC bias drive signal
Color developing AC bias drive signal
Color developing bias level control signal
Figure 4-605
1
Color
developing bias
generation
circuit
or based on the result of image density cor-
CANON 660/2100 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Color developing cylinder
AC
+
DC (negative)