Epson TM U200D - B/W Dot-matrix Printer, Technical Manual

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Rev. B Mechanism Configuration and Operating Principles
TM-U200D/U200PD Technical Manual
Print head unit movement
When the Motor, carriage is driven and the Gear, carriage motor is moved in the direction of
arrow B (forward rotation), the rotational power is conveyed to the Pulley, belt drive, then
the belt. Next the Carriage sub-ass’y, which is fixed to the belt, is moved in the direction of
arrow B.
When the Gear, carriage motor is rotated in the direction of arrow A (reverse rotation), the
Carriage sub-ass’y is moved in the direction of arrow A.
Wire movement when a single dot is printed
When the specified print head drive pulse is input to the drive coil, the iron core is magnetized,
and the actuating plate is pulled in the direction of arrow A. This action pushes the wire toward
the platen. When the wire strikes the ink ribbon and paper against the platen(*), a single dot is
printed.
When the energizing of the drive coil is completed, the wire and actuating plate are returned to
the standby position by the wire return spring and actuating plate spring.
(*) The “platen” is the portion of the Frame, paper feed being struck by the wires during
printing.
Figure 2-3 Print head unit movement
Figure 2-4 Printing
B
B
B
A
A
A
Gear, carriage motor
Pulley, belt drive
Belt
Carriage sub-ass’y
A B
B
A
Actuating
Paper roll
Ink ribbon Wire return
Drive coil
plate
spring
Wire
Wire guide
Iron core
Platen