Epson TM-U950P - B/W Dot-matrix Printer, Technical Manual

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Rev. A Mechanism Configuration and Operating Principles 2-3
TM-U950/U950P Technical Manual
Printing operation
Wire movement for printing a single dot
1. When the drive pulse is sent through the drive coil, a magnetic field is induced in the core,
and the lever plate is pulled in the direction , the dot wire is pushed by the spring
force of the wire towards the lever plate, which moves towards the platen assembly
direction .
2. The pushed-out dot wire contacts the platen via the ink ribbon and paper, so that one dot is
printed.
3. The drive coil current is cut, causing the dot wire and lever plate to return to their original
positions due to the spring action of the wire and the plate.
Forming a character
(9 x 9 dot matrix)
The carriage motor phase switching signal serves as a reference signal for powering the print
solenoids in accordance with the carriage movement, to form a character. One rotation step of
the carriage motor (7.5°) moves the print head unit by approximately 0.339 mm (0.013”).
a
b
Figure 2-3. Dot Wire Operation
CONFIDENTIAL