Outline Of The Image Processing System (Ir8500); Outline - Canon iR8500 Service Manual

4 Outline of the Image Processing System (iR8500)

4.1 Outline

The image processing system has the following major functions:
• CCD (image sensor)
Number of lines:
Number of pixels:
Image size:
• Shading Correction
Shading adjustment:
Shading correction:
• Auto Density Correction
F02-202-01 shows the functional construction related to the image processing system:
Analog image processing block
CCD
Analog
image
processing
CCD/AP PCB
The functions of each PCB of the image processing system are as follows:
[1] CCD/AP PCB:
[2] Reader controller PCB:
COPYRIGHT© 2001 CANON INC.
1 line
7500 pixels
7 × 7 µm
in service mode
executed for each copy
Executed once for every line in main scanning direc-
tion
Digital image processing block
A/D
conversion
drives the CCD, processes analog images, executes A/D
conversion
executes shading correction, executes auto density cor-
rection, converts image data (4 channels → 2 channels)
2000 2000 2000 2000
CHAPTER 2 NEW FUNCTIONS
Reader controller PCB
Shading processing
Auto density correction (AE)
Image data
(4 channels → 2 channels)
F02-401-01
CANON iR8500/7200 REV.1 AUG. 2001
Main
controller
block
2-73