Dirt Sensor Control - Canon imagePRESS C1 P Service Manual

3-2) The machine executes an external light search: for main scanning direction, it turns on the xenon lamp to check its light (reflected) at 4 points using the CCD;
for the sub scanning direction, the machine checks the state of the original sensor.
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 of ADF side 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 Dust Detection Control at Stream Reading
imagePRESS C1 / Color Image Reader-H1 / imagePRESS C1+ (Printer) / imagePRESS C1+
At stream reading from the ADF, the presence/absence of dust is detected at the stream reading positions on the copyboard glass. According to the detection result,
the original reading position is changed, or the image correction is executed to avoid dust appeared in the image.
1. Control Timing
(1) When the job is finished
(2) At paper interval (every 1-print reading)
(external
light)
Point of CCD
detection
Original
1 2 3 4
A B A B A B A B sensor 1
F-5-22
25
F-5-23
5
F-5-24
F-5-25
Inch-configuration
Point of CCD
Original detection
1
size
A B
11"x17"
LGL
LTRR
LTR
STMTR
STMT
absent
:unchanged
F-5-26
Original
2 3
sensor 3
A B A B
:changed
Chapter 5
0012-9682
5-11