Canon iPF825, Service Manual

Page: 117 / 316

Chapter 2
2-47
Printhead contact detection
The printhead contact detects the status of printhead installation by electrical means.
The contact detects the status of contact from voltage changes in the flexible cables on the carriage side that come into contact with two terminals of the printhead
with remote contact surfaces, the power terminals and GND terminal.
Multi sensor
The photo-reflection-type multi sensor is composed of four LEDs (red, blue, green and infrared) and two light-sensitive sensors. It detects the leading edge, skewing,
and width of media and is used for adjustment of the registration, head height, and color calibration.
During head adjustment, the light reflected by the infrared LED and green LED is detected by two light-sensitive sensors to calculate the head height from the
difference between the measurements.
F-2-40
- Service mode: After SERVICE MODE > ADJUST > GAP CALIB. has been carried out, pass paper to make sure that it is detected properly.
Platen
Media
Infrared LED
LED(red) LED(green) LED(blue)
Infrared sensor