Epson Stylus COLOR 1520 Service Manual page 55

3. Pump Mechanism Operation
The pump mechanism absorbs ink inside the printhead and drains the ink to the waste ink drain pads
via the cap. Since this printer has black and color heads, the pump mechanism functions for the both
heads by alternating rotational directions of the PF motor. When the PF motor rotates forward (the
direction for feeding paper), the pump is used for the black head. The PF motor rotates backward
(the direction for feeding back paper) to use the pump for the color head. The pump mechanism is
composed of the 2 rollers: tube, and pulley. To draw the ink, the pulley rotates the rollers squeezing
the tube to produce the negative pressure, which absorbs the ink and drains it into the waste ink drain
pad.
Pulley
Ink Draining
Ink Drawing
PF Motor (Backward):Color Ink Drawing
Pulley
No Ink Drawing
No Ink Draining
PF Motor (Backward):No Black Ink Drawing
Rev. A
Ink Drawing
Ink Draining
No Ink Draining
No Ink Drawing
Figure 2-14. Pump Operation
Operating Principles
PF Motor (Forward):Black Ink Drawing
PF Motor (Forward):No Color Ink Drawing
2-13