Printer Mechanism; Thermal Printhead; Paper-Feed Mechanism - Star Micronics TSP200 Series Technical Manual

PRINCIPLES OF OPERATION
3.

Printer Mechanism

3-1. Thermal Printhead

The TSP400 printers utilize thermal line printing. The thermal printhead consists of a horizontal line of 576 heat elements.
These elements print one line of dots at a time as the paper passes over the head. The printhead is fixed in position; only
the paper moves.
The printer prints a dot by heating the corresponding heat element. The heated element generates a chemical reaction in
the coloring layer of the thermal paper, resulting in the formation of a visible dot.
Thermal head
Heat element
Coloring layer
Thermal paper
Printed point
Platen
Fig. 2-16 Principle of Thermal Printing

3-2. Paper-Feed Mechanism

The paper-feed mechanism is comprised of paper-feed motor, gear train, platen, and thermal printhead. The paper-feed
motor drives the gear train, which in turn rotates the platen. The platen carries the thermal paper past the printhead.
The paper-feed motor is a PM (permanent magnet) type, 4-phase 48-pole step motor. 3 steps feed the paper approximately
0.125mm.
Thermal paper
Gear train
Platen
Paper-feed motor
Thermal head
Fig. 2-17 Paper-Feed Machanism
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