Mechanism And Operation - Radio Shack TRS-80 Service Manual

All and more about Sharp PC-1500 at http://www.PC-1500.info
2. MECHANISM AND OPERATION
The printer rougltly consists of six blocks - a frame, X.<Jirection drive, Y-Oirection drive, pen drive mechanism, color
change
n1echan.ism~
and pen takc-0ut mechanism sections. An explanation is made per e.ach block.
1. Frame section
The frame section has a sfde plate (right), side plate (left), holding plate, and paper guide. The lower edge oi the frame, bent in
the shape of the letter L, acts as a mounting leg.
2. X Drive Mechanism Section
The principal elements of the X-<lirection drive mechanism are the X stepping motor, idle gear, bobbin gear, pulley support base
(left), puUey support base (right), slider unit and wire.
Bobbin Geer
Pulley
Support
8 - (Leftl
Slide Unit
• Step Angle and Minimum Movement Pitch
Stepping Motor
Figure 1
0
Pulley Supp0ort
8-(R' ht)
The reduction ratio between the stepping motor and bobbin gear is I :9.01, and for each stepping motor pulse (18/360°), the
slider unit, that is, X direction movement of pen is 0.2mm. The motive power is transmitted to the bobbin gear via idle gear
and to the slider unit by a wire. The wire tension is maintained by a coil spring.
3. Y Drive Machanism (Paper Feed Mechanism) Section
llte Y-<lirection drive mechanism consists of the Y stepping motor, idle gear, rubber roller unit, p aper holding roller (right) and
paper holding roller (left). The reduction ratio between the Y stepping motor (called as the
Y motor
hereafter) and rubber
roller gear is I :7.86. As the casa with the X direction, the rubber roller movement per each pulse of the Y motor, that is,
the Y direetion movement of the paper, is 0.2 mm.
Do not sale this PDF !!! -43-