Canon ImageRunner iR8500 Series, Service Manual, Page: 265 / 1122

Chapter 5
5-13
5.3.1.4 Outline
0008-7401
/ iR8070
The following parts are associated with the scanner drive system.
F-5-17
[1] Scanner Motor (M101) Control Signal
Used to turn on/off the motor and to control its direction and speed of rotation.
[2] Scanner HP Sensor (PS102) Detection Signal
Used to make sure that the No. 1 mirror base is at home position.
[3] Copyboard Cover Sensor (PS103) Detection Signal
Used to detect the state (open or close) of the copyboard cover.
5.3.1.5 Controlling the Scanner Motor
0008-7402
/ iR8070
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.
F-5-18
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:
F-5-19
[1] Acceleration. Used to accelerate until the speed most appropriate to the read ratio is attained.
Drive signal
Reader
controller
PCB
[1]
[2]
[3]
No. 2 mirror base
Copyboard
cover sensor
(PS103)
Scanner motor (M101)
(forward)
(reverse)
Light-blocking
plate
No. 1 mirror base
Scanner HP
sensor (PS102)
IPC
Scanner motor
Reader controller PCB
J5011
M3
1
5
2
3
6
4
A
A*
B
B*
+24V
Motor
driver
CPU
Speed control
circuit
HP Image leading edge Image end
Stream reading position
(start position)
Stop
Accelerate Maintain
Travel
speed
Travel distance
[1] [2] [3] [4]
Decelerate