Image Processing - Canon iR4570 Series Service Manual

Chapter 5

5.3.6 Image Processing

5.3.6.1 Outline
iR2270 / iR2870 / iR3570 / iR4570 / iR3530
The following shows the major specifications and functions of the machine's image processing system:
CCD
Shading correction
Contact image
sensor (CIS)
CCD
The following shows the functions of the PCBs used by the machine's image processing system:
Reader controller PCB
The machine uses the reader controller PCB to process images for every single image line; specific functions are as
follows:
1) Analog Image Processing
-CCD drive
-CCD output gain correction, offset correction
-CCD output A/D conversion
2) Digital Image Processing
-shading correction
5-22
T-5-8
number of lines: 1
Number of pixels: Total 7488 (Number of
effective pixels: 7180)
size of pixel: 32 x 46.9 ym
shading correction: executed for each job
shading adjustment: executed at power-on
Reader controller PCB
Analog image
processing block
Analog
A/D
image
conversion
processing
F-5-25
T-5-9
CCD drive, analog image processing, A/D
conversion, shading correction
Digital image
processing block
Controller block
Shading
processing
0006-5930