Canon imageRUNNER ADVANCE C3500 III Series, Service Manual, Page: 63 / 1252

■ Control Description
In horizontal scanning direction, sensor level of each original detection position is measured by moving the Scanner Unit to the
detection position shown in the figure in relation to the original setting position. The size in the vertical scanning direction is
determined by using the Original Size Sensor (AB) and Original Size Sensor (Inch).
LTRR
STMT
LTR
LGL
279.4×431.8mm
(11"×17")
Original Size Sensor (Inch)
Inch type
STMTR
CCD original detection position
Original detection
position 1
Original detection
position 2
Original detection
position 3
Original Size Sensor (AB)
B5
A5
A4
B5R
A4R
A5R
B4
A3
K8 K16
AB type
CCD original detection position
Original detection
position 1
Original detection
position 2
Original detection
position 3
Original detection
position 4
Original detection position 5
Original detection position 6
Dust Detection Control
■ Overview
When reading an original, original reading position is changed according to the presence/absence of dust on the Stream Reading
Glass or the Guide Plate of the ADF (on the Platen Roller in case of the reverse model), or image correction is performed to
prevent the dust to be printed on an image. This control is performed only when the ADF is being used and has been closed.
Control timing
Dust evasion control
• At job completion
• At the start of a job (only when one of the following conditions is met)
• At the start of the first job after power ON or recovery from sleep mode
• At the start of the first job after a message prompting cleaning of dust is displayed and then the ADF is opened and then
closed
• At the start of a job when dust evasion control performed at the end of the previous job failed to finish normally
Image correction control
• At paper interval (after each sheet is read)
Main power
switch ON
Start key
ON
Dust detection
control
STBY WMUP
1st
SCAN 2nd
SCAN
Dust detection
control
Dust detection
control
Control description
Dust evasion control
• At job completion
The Reading Sensor detects presence/absence of dust at the reading position A, B, and C in that order, and the position
where dust is least present becomes the reading position for the next job.
• When a job starts
Like the time of completion of a job, presence/absence of dust is detected at all positions (A, B, and C in that order).
The position where dust is least present is used as the reading position and reading starts.
2. Technology
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