Automatic Sheet Feeder (Asf) - Epson Stylus COLOR 440 Service Manual

EPSON Stylus COLOR 440, 640, and 740 Chapter 2 Operating Principles

Automatic Sheet Feeder (ASF)

When the user sets a stack of paper in the printer, it rests on top of the
upper ledge of the pad , shown in Figure 2-8. The stack remains on the
pad while individual sheets are fed into the paper path. Sometimes,
however, more than one sheet of paper slips into the paper path during
printing. If this is not corrected, it can cause paper to jam when the
printer tries to load the next sheet of paper. To prevent this, the PF
motor rotates backwards at the beginning of each paper feed cycle.
This causes the cam to rotate counterclockwise, catch the paper return
lever, and lift it upward, as shown in the figure at right. At the same
time, the hopper and the pad are pushed backwards, away from the D-
cut paper loading roller, leaving a gap to prevent friction with the paper.
As the cam continues to rotate, any paper that has slipped into the
paper path is caught by the return lever and returned to its proper
position on top of the pad.
Figure 2-8. ASF Unit Operation
When the PF motor resumes normal forward motion, the cam and the
D-cut roller rotate clockwise, allowing the paper return lever to move
downward and clear the paper path. At the same time, the hopper and
the pad move forward and press the paper against the D-cut roller. As
the D-cut roller continues to turn, it draws the top sheet of paper off the
stack and feeds it into the printer, until the roller has turned so that its
flat side is parallel to the paper. At this point, the paper is fully loaded
and only the paper pinch roller remains in contact with the paper. This
is the ASF's home position. A sensor detects this position and causes
the printer to disengage power from the ASF.
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