Canon SmartBase MPC400 Service Manual page 44

SmartBase MPC600F/MPC400 Chapter 2: Technical Reference
d) Pump
This is a tube pump system consisting of two ink tubes (one for black and one for color) pressurized by
a rotating roller. A negative pressure is thereby created to suck the ink. Inside, there is a valve dedicated
to black ink and one dedicated to color ink. When the valves close or open separately or
simultaneously, only the black ink (color valve open) or color ink (black valve open) can be sucked or
both inks can be sucked (black and color valves closed).
The amount of ink sucked can be high, medium, or low depending on how much the roller rotates.
The pumping operation is executed with the rotation of the roller after the carriage is released from the
capping position and both valves are opened.
The degree of rotation of the pump's roller and the timing of the rotation are controlled by the step
count in accordance with the initial position detected by the pump sensor.
Rotation Direction for
Ink Suction
Valve Open
Valve
Black Ink Tube
Closed
Figure 2-9 Pump Operation
Rotation Direction for
Wire/Capping
Rotating Roller (inside)
Color Ink Tube
2-14
To Waste-Ink
Absorber