Minolta Di620, Manual, Page: 59 / 466

M-40
1155SBM0807A
8-7. Scanner Motor Drive Control
<Overview>
•
The Scanner Motor is a DC server motor. The motor is controlled by PWM (pulse
width modulation); that is, the speed controlled by varying the average width of
the motor drive pulse.
•
The motor incorporates a built-in photosensor and pulse disk that generate a
“monitor” pulse with each rotation of the shaft. This signal is transmitted to the
Image Processing Board, which uses it to detect the motor’s speed and travel dis-
tance.
•
The Processing board determines the current motor speed based on the rate of
the incoming monitor pulse, and adjusts the scanner drive pulse as necessary to
maintain stable motor speed.
•
At the same time, the SCP uses the monitor-pulse count to control the scanner’s
travel distance, where the pulse count required for a full motion varies according
to the paper size and the magnification.
Control Signal Scan Stop WIRING DIAGRAM
M31
(Scan Signal)
PJ9IB-10B D-17
Control Signal UNBLOCKED BLOCKED WIRING DIAGRAM
PC55 PJ9IB-2A D-18
L H
H L