Paper Path System; Others - Canon iPF720 Service Manual

The printhead temperature is transmitted to the main controller via the carriage relay PCB.
The printhead temperature is used to help control the head drive and detect abnormal printhead temperatures.
Printhead contact sensor
The printhead contact sensor detects the status of printhead installation by electrical means.
The sensor 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.

2.5.4 Paper path system

Media sensor
The photoreflector-based media sensor detects the presence or absence of paper on the platen.
The sensor detects the presence of paper when it receives sensor light reflected upon the paper.
Feed roller HP sensor
The feed roller HP sensor sets an LF eccentricity correction home position by detecting transitions from black (shielded) to white (transmitted), or a reference, in
the scale in the code wheel.
Feed roller encoder sensor
The feed roller encoder sensor detects the carriage position from slits in the feed roller pulley as it is driven.

2.5.5 Others

Temperature/humidity sensor
The temperature/humidity sensor detects the temperature and relative humidity around the printer to implement head height adjustment, maintenance jet control,
waste ink evaporation calculation and suction fan control on the basis of the temperature and relative humidity thus measured.
Feed roller HP sensor
Feed roller
encoder sensor
F-2-39
Temperature/humidity
detection sensor
F-2-40
Media sensor
Chapter 2
0012-6327
0019-6559
2-41