Swecoin TTP 101, Service Manual

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TTP 101 Kiosk Printer Sub-system – Service Manual 0102 12
3.1.1 Paper transport
During paper loading and printing, the paper is transported by the print platen driven by
the paper-feed motor through a gear mechanism. As long as there is no paper detected
by the presenter sensor at the front of the printer, the eject-rolls will slowly rotate counter-
clock-wise as the platen advances the paper. The reason for this is to enable the eject
rolls to catch the leading edge of the paper. The presenter motor stops when the
presenter sensor detects the paper edge.
Figure 6. Paper transport
As the paper advances during printing, the loop-building ribs force the paper to form a
loop of increasing height. The document is thus kept inside the printer until the printing is
completed. This patented function prevents the customer from pulling the paper during
printing, which would otherwise result in distorted printout, paper jam and varying
document length.
After completed printout and separation, the presenter motor ejects the document at high
speed. The presenter sensor reports to the printer firmware when the trailing edge of the
document passes the sensor. This sensor is therefore also used to verify that the
presenter module is cleared after each eject-operation.
It is possible to decide, by software control, whether the document should be completely
or only partially ejected. In the latter case, the customer has to pull the cut document out
of the printer. If very long documents are printed, it is also possible to eject portions of the
document during the printing process.