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©
2001 CANON INC. 2000 2000 2000 2000 CANON iR2200/iR2800/iR3300 REV.0 MAR. 2001
CHAPTER 2 ORIGINAL EXPOSURE SYSTEM
2-5 R
1.3 Enlargement/Reduction (zoom)
[1] When the copyboard cover is used, the ratio may be between 25% and 800% and the
speed of the scanner is controlled.
[2] When the ADF is used, the ratio may be between 25% and 400% and the speed of
moving the originals is controlled.

1.3.1 Changing the Reproduction Ratio in Main Scanning Direction

For main scanning direction, the original is read at 100% (for both copyboard and ADF);
the size is changed by processing data in the main controller unit.
[1] To reduce, data units are skipped when writing image data to the line memory.
[2] To enlarge, data units are read multiple times when reading image data from the line
memory.

1.3.2 Changing the Reproduction Ratio in Sub Scanning Direction

For sub scanning direction, the speed of the scanner/movement of the original is changed.
However, for a reduction between 25% and 49% and enlargement between 401% and 800%,
data processing in the main controller assembly is also used in combination.
[1] For enlargement, the speed of the mirror/original is reduced from that used in Direct:
e.g., at 200%, the speed is 1/2 of the speed used in Direct.
[2] For reduction between 50% and 99%, the speed of the mirror/original is increased;
e.g., at 50%, the speed is twice as high as that used in Direct.
F02-103-01
[3] To reduce to between 25% and 49%, the image data read at 50% and 98% is subjected
to skipping (1/2) in the main controller unit.
[4] For an enlargement between 401% and 800%, image data read at 200% to 400% is
sub-jected to repeating (doubling) in the main controller assembly.
400%200%100%
50%
2
1
1/2
1/4
(speed ratio)
(image ratio)