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4.
Scanner
Motor Drive System
Operation
The
scanner
motor
is a 4-phase
stepping
motor, and rotates CW and CCW
depending
on the combination
of pulses (A,
K B, E) to each phase.
a.
Clockwise Rotation
The
scanner
motor
driver
outputs
pulses,
and the motor
rotates
CW. This
moves
the
lens
in
the
direction
for
REDUCTION,
and
the
scanner
moves
forward.
For REDUCTION
copying,
the motor
speed increases to move the scanner faster
(forward).
b.
Counterclockwise
Rotation
The scanner
motor is driven
CCW by
pulses of phase relationship
opposite of that
used to drive it CW. This moves the lens in
the direction
for ENLARGEMENT,
and
moves the scanner in reverse.
c.
Mechanism
The motor-driver
circuit
controls
the
direction
and speed of the scanner
motor
based on the following signals generated
by
the microprocessor
on the DC controller:
l
scanner motor drive commandMD)
A scanner forward command
(SCFW)
*
scanner speed control command'(SCCLK)
--
1
A
J109-1
A
-2
p
M2
Scanner
trotor
B
-3
B
-1
I
Forward
SCMD
SCFW
0
0
I
Reverse
0
I
1
I
1
Braking
1
0
1
l
1
1
Still
1
1
1
If
1
"1' and '0' are reversed from previous states.
"'1'
or '0' is maintained.
Table 3-3
The motor
driver
circuit
operates
as
shown
in
Table
3-3
based
on
the
--
combinations
of SCMD and SCFW.
When the scanner
is moving
forward,
the number
of SCCLK
pulses
is varied
according
to the reproduction
ratio selected;
when
the scanner
is moved
in reverse,
however,
the number remains the same.
E202 is indicated
if the scanner
does
not reach the home position within a specific
time after it has started to move.
Scanner
speed conirol command
Scanner forward
-3
command
(SCFW)
-7
Scanner
motor
-5
drive command
(SCMD)
-9
.
1
AC diver /DC
power
Supply
PCB
Figure 3-15
: controller
P
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