Canon Color imageCLASS MF9170c Service Manual page 127

Chapter 7
7) The main controller controls a video signal for each color based on the degree of color displacement of each color received, and makes adjustments of the main
scanning start position, main scanning magnification, and sub scanning start position.
Light emitter (LED)
Light receiver (PD)
7-12
Main controller PCB
DC controller PCB
Color displacement/density
sensor (right)
Color displacement/density signal
Color displacement/density LED
drive signal
Color displacement/density sensor (left)
ETB
Pattern image for
color displacement correction
Color displacement signal
F-7-16