Space Mechanism And Operation - Atari 1025 Field Service Manual

SPACE MECHANISM AND
OPERATION
SPACING MECHANISM
The
space
mechanism
consists of the following:
• Pulse
motor
with synchro
belt
pulley
•
Synchro
belt
•
Two
guide shafts
•
Carriage
•
Home
sensor
•
Home
sensor plate
Spacing and carriage
return are performed by
driving the
carriage with a pulse motor.
The
carriage
is
guided by two
shafts
mounted
parallel to
the
platen.
SPACING OPERATION
The
carriage with the
print
head mounted
on
it
moves
parallel to
the platen along the
upper and lower guide
shafts (see
Figure
1-2).
One
end
of the carriage
frame
is
fixed
to
the synchro
belt.
As
the
pulse
motor
turns clockwise, the carriage
assembly
is
driven
from
left to right.
The
spacing
mechanism
is
designed
so that
when
the
pulse
motor
turns 4 steps
(30°),
the carriage moves
2.54
mm
(1/10
inch).
CARRIAGE RETURN OPERATION
When
the carriage
return
code (EOL)
is
received, the
pulse
motor
is
driven
counterclockwise by
the
signal
from
the control
circuit.
The
carriage
moves
from
right to
left until the
home
sensor plate enters the opening
in
the
home
sensor.
The
home
sensor consists
of an
LED
photodiode
pair.
When
the
home
sensor plate
enters the
sensor, the
light
is
interrupted and a
signal
is
generated
to stop the motor.
When
the
pulse
motor
stops,
the carriage stays at the
start position
until
the next
line
is
ready
to be printed.
Guide Shaft
(upper)
Figure
1-2. Spacing
Mechanism
Atari 1025 Printer
Field
Service Manual
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