COPYRIGHT © 1999 CANON INC. CANON imageRUNNER 400/330 REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
4-7
CHAPTER 4 IMAGE FORMATION SYSTEM
III. DIGITAL IMAGE PROCESSING
A. Outline
The digital image processing block processes image signals from the analog image processing
block or from the various extension boards. Figure 4-300 is a block diagram showing the items of
processing.
In the case of making a single copy (a single copy from a signal original), the image data is
converted to 12000-dpi (equivalent) images by smoothing after binary processing, and is sent to the
laser driver PCB (direct copying). In other cases, image data is stored in memory first and then
transferred to the laser driver PCB (memory copying).
Figure 4-300
CCD PCB
600x600 dpi
Shading correction
Total processing
• Enlargement/reduction
• Shift
• Image composition
enlargement/reduction
• Edge emphasis
• Sharpness
• Nega/posit reversal
Image synthesis
(overlay processing)
Density processing
System motherboard
laser driver PCB
Analog image processing block
Digital image processing
Laser exposure block
• Binary processing
• Screen processing
• Resolution conversion
(for fax)
• Smoothing
Compression/
decompression
Image memory
To extension board
Direct copying
600x600 dpi
600x600 dpi
Fax data
J717
J717
J500
J500
Image processor PCB
Fax data