Service manual

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 detects the paper loaded in
the clamp, and then speeds up to draw more of the paper around the drum. This
continues 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
8699-12
Drum
rotates
forward
to close
clamp
Paper
clamped
to drum
Paper clamped
sensor
8699-13A
Drum
rotates
to print
start
position
Thermal head is lowered
to top of paper