II- 1
CHAPTER II THEORY OF OPERATION
2.1
OUTLINE OF MECHANISMS
2.1.1 Print
Mechanism
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Structure of Thermal Head
This machine adopts direct thermal printing system. The thermal head consists of 1296
pieces of heating elements arrayed in vertical single row as shown in the Fig. 2.1-1.
The dimension of each heating element is vertical length 0.0847(0.0847mm pitch) x
horizontal width 0.13mm.
Pitch 0.0847mm
0.13mm
Fig. 2.1-1 Heating Elements of Thermal Head
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Printing Process
A thermal tape is pressed against the thermal head in the printing process by the force
comes from a nip between the cylindrical rubber platen and the thermal head. At this
timing, voltage is applied selectively to 1296 pieces of heating elements arrayed on the
thermal head. By this voltage application, the heating elements generate heat and the
thermal tape develops dots by itself at heat sensing points. After application of voltage the
thermal tape is fed to the next printing position by the platen (0.0847mm).
This printing cycle is repeated and characters and geometries are printed on the tape.
One time travel distance (0.0847mm) is shorter than the width of a heating element
(0.13mm), so that continuous printing cycle can print characters and geometries on a tape
by developing dots with no gap.
