Canon 7086 Series Service Manual - page 205
Chapter 5
5-19
F-5-44
5.3.6 Image Processing
5.3.6.1 Overview
0011-2241
iR7105 / iR7095
The PCBs used in the image processing system have the following functions:
CDD/AP PCB: CCD drive, analog image processing, A/D conversion
Reader controller PCB: shading correction, image data conversion (4 channels -> 2 channels)
F-5-45
1. Analog Image processing
- CCD drive
- CCD output gain correction, offset correction
- CCD output A/D conversion
Correction Algorithm
Data on light reflected
by the white plate
(shift shading))
Data on light reflected
by the white plate
(fixed shading)
Identifies the coordinates
of the start of dust and width
The machine corrects the correction
coefficient of the area of dust using data
for areas on both sides
Point of white plate data
measurement at time of fixed shading
White plate data correction
area at time of shift shading
White plate
Dust
Comparison
CCD/AP PCB
Reader controller PCB
CCD
A/D
conversion
Analog
image
processing
Analog image processing block
Controller block
distal image processing block
shading processing
image data conversion
(4-system -> 2-system)