Brother PT-2420PC, Service Manual

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II-1
CHAPTER II GENERAL MECHANISM
2.1 MAIN MECHANISM
2.1.1 Print Mechanism
(1) Structure of Thermal Head
This machine uses thermal transfer printing. The thermal print head has a heat generator
consisting of 128 heating elements which are vertically aligned as shown in Fig. 2.1-1.
Out of those 128 heating elements. Each heating element is 0.195 mm wide by 0.141 mm
high.
Fig. 2.1-1 Heat Generator of Thermal Head
(2) 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 128 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.
Iron-on transfer tape when using iron-on transfer tape cassettes.
** When using non-laminated thermal film tape cassettes, no ink ribbon is sandwiched.
[For tape cassettes except non-laminated thermal film 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.
[For non-laminated thermal film tape cassettes]
If the selected heating element(s) generates heat, the thermal film tape develops itself to
produce a dot(s) on the tape. The tape is advanced and the next heating cycle is repeated,
thus forming a character on the tape.