Brother PT 1800 - P-Touch 1800 Thermal Transfer Printer, Service Manual

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II - 1
2.1 THEORY OF OPERATION
2.1.1 Print Mechanism
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Structure of Thermal Head
This machine uses thermal transfer printing. The thermal print head has a heat
generator consisting of 128 heating elements (96 out of them are actually used) which
are vertically aligned as shown in Figure 2.1-1. Each heating element is 0.195 mm wide
by 0.141 mm high.
Figure 2.1-1 Heat Generator of Thermal Head
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Printing Process
When the cylindrical rubber platen is pressed against the thermal print head with the
tape* and ink ribbon** sandwiched inbetween, the CPU applies electric power to the
selected ones of those 96 heating elements.
* Laminate tape when using laminated tape cassettes.
Non-laminated tape when using non-laminated tape cassettes.
Instant lettering tape when using instant lettering tape cassettes.
Non-laminated thermal film tape when using non-laminated thermal film tape cassettes.
Iron-on transfer tape when using iron-on transfer tape cassettes.
** When using non-laminated thermal film tape cassettes or stamp tape cassettes, no ink ribbon
is sandwiched.
[ For tape cassettes except non-laminated thermal film tape cassettes and stamp tape
cassettes ]
If the selected heating element(s) generates heat, the ink on the sandwiched ribbon will
be melted and transferred to the tape, producing a dot(s) on the tape. The ink ribbon
and the tape are advanced and then the next heating cycle is repeated, thus forming a
character on the tape.