Service manual

7-2. Physical Characteristics of the printer
The PTMPG printer is composed of five parts: a frame unit ,
an X~irection drive unit. a Y~irection drive unit, a pen
drive m ec hanism & color-chan ge mechanism, and a pen
take-o ut mechanism_ Each part is described below.
1. The Frame unit
The frame un it consists of a right side·plate, a left side-
plate, support plate and paper guide. The lower end of the
frame is used for mounting.
2. Th e X·Direction Drive unit
The X ~irection drive unit con\ists of an X stepping motor,
an idler gear, a pulley gear, a pu ll ey suppo rt rest (left)
u
nit, a p ull ey support rest (r ight) unit, a slider unit, and a
wi re. The gear reduction ratio of the stepp ing moto r and
pulley gear is 1 :13.9. A sing le pulse of the stepping motor
(18 degrees/360) moves the slider unit or pen by O.2mm in
the X direction. Power transmission from the pulley gear
to the slider unit is made by the wire, which is tensioned
by a coil spring.
I
dler Gear X Stepping Motor
Pulley Support
Rest lIeft) Unit
Slider Unit
3. The Y·Direction Drive unit
Wi re
Pull ey Support
Rest ( rig h t) Unit
The Y~i r ection drive unit is th e paper·feed mechanism.
It consists of a Y stepping motor, an idler gear, a platen
roller unit, a paper holder installing plate (left), and a
paper holder installing plate (right). The reduction ratio
between the Y steppi ng motor (Y motor) and the platen
gear is 1:.7.88. One pulse of the Y motor mo v es the platen
ro li er, or recordi ng paper, by O.2mm in the Y direction.
P
laten Roller unit
\
Paper Hol der
~~~~~ I nstalli ng
"- Plate (r ight)
~
4. The Pen Drive Mechanism & Color~han98 Mechanism
This part consisu of two main blocks: the pen drive
mechanism a nd the co lor -c hange mechanism, each of which
is desc ribed below.
- 73 -
PC- lGOO
1) The Pe n Dri ve Mecha ni sm
The
pe n drive mechanism consists of a Z-motor unit, a
Z·cam gear, an ejection lever shaft unit, a roller lever
and a ball point pen.
The
pe n's up/down movements are performed by the
rotat io n of the cam gear, whose motive power is tra ns-
ferred to the ejection
leve r through a pin. Considering
the
E point below as an origin, the pen comes down
when the cam gear rotates three (3) steps along Z
(+)
direction, and the pen CXlmes up when the cam gear
rotates three
(3) steps from the pen-down position
along Z
(-) direction.
®
® . ~~©
(1) View of the Z -Ca m Gear
®
® @
15 Jt9ps
(2) Z·Cam Gear s tep s
2) The Color·Chan
ge Mechan ism
The color change mechanism is composed of a Z-motor
unit, a Z·cam gear unit, an ejection
lever shaft unit, a
r
ot ary holder which is in th e slider unit, and a color-
chan
ge lev er.
The color-change is performed by the movement of the
Z-cam gear gram from E poi
nt to 0 point a nd then the
reciprocat io n of it between 0 and A points. The gear
of the rotary holder has
32 teeth, and e ig ht (8) reci-
procations of the 15·step movement make for a color
change once.
5_ The Pen Take-Out Mechanism
Th e pen take-out mechan ism is a lev er which is attached to
the slider unit. To replace the pen with a new one, fi rst
press down the pen take-out lever. Then, p
id< up the pen
from the rotary holder and replace it. A pen can be r
e-
palced at any position on the sl ide r unit.