Theory Of Operation; Print Mechanism - Brother PT-2500PC Service Manual

2.1 THEORY OF OPERATION

2.1.1

Print Mechanism

n Structure of Thermal Head
This machine uses thermal transfer printing.
generator consisting of 128 heating elements which are vertically aligned as shown in
Fig. 2.1-1. Each heating element is 0.195 mm wide by 0.141 mm high.
n 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.
Porous-stamp tape when using stamp 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.
Fig. 2.1-1 Heat Generator of Thermal Head
II - 1
The thermal print head has a heat