Dirt Sensor Control; Detecting Dust In Stream Reading - Canon ImageRunner iR8500 Series Service Manual

AB-Configuration
Originals
size
A3
B4
A4R
A4
B5
B5R
None

5.3.5 Dirt Sensor Control

5.3.5.1 Detecting Dust in Stream Reading

iR105i/iR105+ / iR9070
In addition to the common points for stream reading, the machine uses an additional 6 points each for small-size and large-size sheets at intervals of 0.5
mm to avoid areas of dust (in total, 7 points for small-size and 7 points for large-size).
If it detects dust, however, it changes the point of reading to prevent dust from appearing in images. The detection of dust is executed at the end of each
single job that uses stream reading; the machine moves the ADF belt idly when stream reading is selected and identifies any black line as an area of dust.
When it detects dust, it resets the current point of stream reading, and uses the point of reference on the leftmost edge for dust detection; if dust is detected,
it moves the point of stream reading to the right by 1 point (0.5 mm) for detection of dust for a second time. If dust is not detected, the machine uses that
point as the point for stream reading. If dust is detected once again, it will use the next point. If dust is detected at all 7 points, the machine will indicate
the message "Copyboard Glass Soiled," which will remain unit the ADF is opened and the copyboard glass is cleaned. The machine will not use stream
reading but use fixed reading as long as the message remains.
Dust
Black line on
output
Advise the user to clean the area where the CCD stops in stream reading if the message has appeared. A label indicating the points for stream reading (for
small-size and large-size) is attached to the rear of the copyboard glass.
If a jam has occurred, the machine will not execute dust detection at the end of a job. If the ongoing job is cancelled, it will execute dust detection at the
end of operation.
Point of CCD detection
Original
1 2 3 4 sensor
yes yes yes yes yes
yes yes yes no yes
yes yes no no yes
yes yes yes yes no
yes yes yes no no
yes no no no yes
no no no no no
T-5-16
Inch-Configuration
Originals Point of CCD
detection
size 1
11"x 7" yes
LGL yes
LTRR yes
LTR yes
None no
yes: Changes no: Does not changes
3 mm (7 points)
F-5-46
Original
2 sensor
yes yes
no yes
no no
yes no
no no
Chapter 5
0006-9651
5-25