Specifications

10-6. Scanner Motor M11 Control
<Overview>
•
A DC servomotor is used for Scanner Motor M11. The pulse width
modulation, or PWM, control is employed in which the average voltage is
controlled by varying the width of the Scanner drive pulse which is the
voltage input to M11.
•
M11 has a built-in photosensor and pulse disk. Their function is to
convert the Motor shaft speed into a corresponding series of pulses.
This pulse signal is input to Scanner Control Processor Board PWB-J.
•
PWB-J then calculates the Motor speed using the period of the pulse
signal applied to it and controls the Scanner drive pulse which is to be
applied to the Motor. This effectively stabilizes the Motor speed.
•
The pulse signal applied to PWB-J is also used to determine the
distance over which the Scanner should travel. This distance is
represented by the number of pulses corresponding to each paper size
and zoom ratio.
<Scan/Return Switching and Braking of M11>
•
M11 is turned forward to move the Scanner in the scan direction, turned
backward to move the Scanner in the return direction, or braked by the
Motor Forward and Backward signals input to PWB-J. Details are as
follows.
Motor Forward Signal
(Pin 13 of IC3J)
Motor Backward Signal
(Pin 15 of IC3J)
Turns Forward
H L
Turns Backward
L H
Braked (in Scan Motion)
L H
Braked (in Return Motion)
H L
•
The brake control in the return motion is provided as follows, since M11
builds up its speed to the maximum level during the return motion. The
Motor Backward signal is first alternated between HIGH and LOW states
to reduce the input voltage to M11 to a low level. After M11 is
decelerated to a given speed through this operation, the above brake
control is performed.
Motor Forward Signal
Braking
Scanner Motor M11
1075T98MCA
Motor Backward Signal
L
H
L
H
Forward Rotation (Scan)
Backward Rotation (Return)
Deceleration Braking
M-45