Canon imageRUNNER 2270 Service Manual page 187

Chapter 5
Main power switch
ON
WMUPR
F-5-22
<Particulars of Control>
-At the End of a Job (dust detection)
The contact image sensor (CIS) checks the light reflected by the surface of the platen roller
of the ADF at the read point for the presence/absence of dust. Presence of dust is detected
at points A, B, and C in this order. The point where least dust is detected will be used as the
read position for the next job.
The point selected here will be used as the read position for the next job.
- For control at the end of a job, if an original is placed in the ADF with dust detected at all
points (A, B, C), the machine will indicate a message on its control panel to prompt
cleaning of the glass surface. The Start key will remain invalid until this message is
cleared.
-At the Start of a Job (dust bypass)
Presence of dust is detected at points A, B, and C in this order in the same manner as at the
end of the job. Read will take place at the point where least dust is detected.
5-22
Start key
ON
STBY
Dust detection control
1st
SCAN
Dust detection control
Dust detection control
2nd
SCAN