Service Manual
5-11
Theory of Operation
5
The drum slowly rotates forward (clockwise, viewed from the left side),
automatically closing the spring-loaded clamp until the paper-clamp sensor 1
detects the paper loaded in the clamp, and then speeds up to draw more of the
paper around the drum. Paper clamp sensor 2 double checks that the paper is
still clamped in the drum as it rotates. The drum rotate for a complete revolution
to clear the paper out of the paper load path. It continues rotating until the
leading edge of the paper (the clamped end) is beneath the thermal head, ready
for printing.
The position of the drum is determined by the drum motor. At this time, the
transfer roll motor is energized to draw the transfer roll to its start position with
the leading edge of its yellow band at the thermal head. The sheet of paper and
the transfer roll are now in position for printing.
Figure 5-5 Clamping the paper
Figure 5-6 Positioning the paper for printing
9015-37
Drum
rotates
forward
to close
clamp
Paper
clamped
to drum
Paper clamped
sensor 1
p
p
sensor 2
9015-38
Drum
rotates
one full
revolution
and continues
to the print
start position
Thermal head is lowered
to top of paper
