Dirt Sensor Control; Stream Reading Dust Detection Control - Canon iR C6800 Series Service Manual

Chapter 5
4. ADF Cover Fully Closed (5 deg or less).
The machine checks for a change in the output levels of the sensors for 2 sec after the ADF open/closed sensor has
identified the ADF as being "closed"; the machine assumes the absence of an original at points without a change.
The machine then identifies the size of the original based on the combination of changes at 5 points.
5. Standby (in wait for a press on the Start key)
No. 1 mirror base: at point of original detection
xenon lamp: off
original sensor: off
AB-Configuration
Original
size
A3
B4
A4R
A4
B5
B5R
A5
B6
absent

5.3.5 Dirt Sensor Control

5.3.5.1 Stream Reading Dust Detection Control

The machine checks the stream reading glass and the ADF platen roller for the presence/absent of dust. It then
changes the point of reading or executes image correction depending on the result of detection, thereby avoiding
reproduction of dust particles in its output images. The machine executes the detection mechanism only when the
ADF is used:
5-16
Point of CCD
detection
1 2 3 4
A B A B A B A B
5
F-5-24
F-5-25
Inch-configuration
Original
Original
1
size
sensor 1 A B
11"x17"
LGL
LTRR
LTR
STMTR
STMT
absent
:unchanged
F-5-26
Point of CCD
detection
Original
2 3
sensor 3
A B A B
:changed
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