Controlling The Scanner Motor - Canon iR8500 Service Manual

3.6.2 Controlling the Scanner Motor

The system used to control the scanner motor is constructed as follows:
The motor driver turns on/off the scanner motor and controls its direction and speed of
rotation in keeping with the signals from the CPU, IPC, and speed control circuit.
Reader controller PCB
a. Controlling the Motor When Scanning an Image
When scanning an image, the motor is controlled as follows, thereby controlling the
movement of the No. 1 mirror base unit:
Stream reading position
(start position)
Travel
speed
[1] Acceleration: Used to accelerate until the speed most appropriate to the read ratio is
attained.
[2] Approach run: Used to ensure that speed stabilizes.
[3] Image read: Used to read the image at a specific speed suited to the read ratio.
[4] Deceleration: Used to enable the scanner to speed down and stop promptly, starting at
the end of the image.
COPYRIGHT © 2001 CANON INC.
CPU
IPC
Speed control
circuit
F02-306-02
HP Image leading edge
Accelerate
[1] [2]
F02-306-03
2000 2000 2000 2000 CANON iR8500/7200 REV.1 AUG. 2001
CHAPTER 2 NEW FUNCTIONS
+24V
J5011
A
1
5
Motor
A*
2
driver
B
3
6
B*
4
Maintain
[3]
Travel distance
Scanner motor
M3
Image end Stop
Decelerate
[4]
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