Various Control; Magnification Change In Horizontal Scan Direction; Dirt Sensor Control; Outline - Canon imageRUNNER 1019J Service Manual

Chapter 4

4.3 Various Control

4.3.1 Enlargement/Reduction
4.3.1.1 Magnification Change in Vertical Scan Direction
In the Book mode or when the ADF is used
In the vertical scan direction, the image is read at 100%. Magnification is changed by processing data on the
image processor PCB.

4.3.1.2 Magnification Change in Horizontal Scan Direction

In the horizontal scan direction, magnification is changed as follows depending on the selected magnification
rate:
1) When magnification is reduced to 50-99%
Data is processed on the image processor PCB with the original scan speed held at 118 mm/sec.
2) When magnification is increased to 100-200%
The original scan speed (in the Book mode)/original feed speed (when the ADF is used) is changed within the
range of 118 mm/sec to 59 mm/sec depending on the selected magnification rate. Data is not processed on the
image processor PCB.

4.3.2 Dirt Sensor Control

4.3.2.1 Outline

The machine changes the original read position or corrects the read image depending on the presence/absence
of dust on the stream reading glass or ADF platen guide, thus preventing dust from showing up in the image.
This control is performed only when the ADF is used and it is closed.
[Control Timing]
- At job end
- Immediately before scanning (one sheet at a time)
Main power
switch
ON
WAIT
[Description of Control]
- At job end (Dust detection)
The contact sensor (CS) checks the light reflected by the ADF platen guide surface at the read position for
presence/absence of dust. After completion of a job, dust detection is performed three times. First, dust detection
is performed once at position A. If no dust is detected at position A, dust detection is performed
twice there. If no dust is detected, the original is scanned at position A. If dust is detected at position A, move
to position B and dust detection is performed twice at position B. If no dust is detected at position B, the original
is scanned at position B. If dust is also detected at position B, move to position C and dust dete ction is performed
once at position C. If dust is also detected at position C, a relevant message is displayed on the operation panel.
Start key
ON
STBY
1st
SCAN
Dust detection control
F-4-8
2nd
SCAN
Dust detection control
Dust detection control
0013-1093
0013-1094
0013-1096