Canon WS8400 Service Manual page 68

Chapter 2
d) Lift unit
The lift unit raises the cap and wiper units by reverse rotation of the pump motor when the carriage returns to the home position for capping, wiping, and
cleaning. Also, during scan, the lift unit is kept lowered to enable back and forth movement of the carriage on the purge unit. The up/down movement
timing is detected by the PG position H sensor and the rotation is controlled by the pump motor (stepping motor).
d) Sensors
Sensors are located in the purge unit for detecting the status of the printer components.
For more information, see Technical Reference > Detection Functions Based Sensors.
2-18
Push rollers
to Maintenance cartridge
Cap
Pumps
Pump home
position sensor
F-2-18
Lift unit
F-2-19
Cap
Ink tubes
Pump motor
PG position H sensor
Pump motor