Canon iR C6800 Series Service Manual page 192

Chapter 5
Reader controller
PCB
CPU
1 Scanner motor control signal
F-5-13
a. Moving the Scanner in Reverse After an Image Scan
After an image scan, the No. 1 mirror base is moved in reverse to shading position at 234 mm/sec regardless of the
selected color mode.
b. Moving the Scanner Forward for an Image Scan
When making an image scan, the No. 1 mirror base unit is moved by controlling the motor as follows:
Start position
Shift
speed
1. Acceleration Zone: accelerates to suit the selected mode
2. Approach Zone: moves for speed stabilization.
3. Image Read Zone: reads the image at a specific speed.
4. Deceleration Zone: past the image trailing edge, immediately decelerates and stops.
The machine uses the following scanning speeds to suit different modes;
Function
Copier
SEND
5-10
Interface PCB
J202 J308
J203 J307
[1]
Motor
driver
Image leading edge
Acceleration
[1] [2]
Shift length
(if black-and-white/SEND mode, twice as fast as in full-color mode)
Mode
black and white
full color
black and white
full color
Scanner
+24V/15V
motor
J306
A M501
3
1
A*
4
B
5
2
B*
6
Image trailing edge
Normal speed
[3]
F-5-14
T-5-5
Scanning speed
234 mm/sec
234 mm/sec
468 mm/sec
234 mm/sec
Stop
Deceleration
[4]