Led Intensity Adjustment; Enlargement/Reduction; Enlargement/Reduction In Main Scanning Direction - Canon iR1600 Service Manual

CHAPTER 3 IMAGE READING/PROCESSING SYSTEM

4.7 LED Intensity Adjustment

So that the image data read by the CS unit will always be optimum, the length of time
during which the LEDs are ON when reading a single line is controlled.
In LED intensity adjustment, the light of the LEDs is directed to the standard white
plate during pre-scanning, and the image data thus collected is evaluated to see if it is
within a specific range; if, for instance, it is outside the range, the length of time is de-
creased.

4.8 Enlargement/Reduction

The machine allows enlargement/reduction between 50% and 200%, set in increments of
1%.

4.8.1 Enlargement/Reduction in Main Scanning Direction

The ratio in main scanning direction (drum axial direction) is changed as follows: in book
mode and ADF mode, the original is read at 100%; thereafter, the collected data is subjected
to processing by the image processor PCB to suit the selected reproduction ratio.
The machine varies the ratio based on a linear correction method.
3-14
COPYRIGHT© 2002 CANON INC. 2000 CANON iR1600/iR2000 REV.1 JAN. 2002