Image Processing; Overview - Canon imagerunner C5180 Service Manual

6.3.6 Image Processing

6.3.6.1 Overview

The following shows the major functions of the machine' s image processing system:
- CCD (image sensor)
number of lines: 3 (RGB, 1 line each)
number of pixels: 7350
size of pixel: 9.3 x 9.3 ym
- Shading Correction shading adjustment: in service mode
shading correction: performed for every copy
Analog image processing block
CCD
Analog image
processing
CCD/AP PCB
The following shows the functions of the PCBs associated with the image processing system:
CCD/AP PCB: CCD drive, analog image processing, A/D conversion
reader controller PCB: shading correction
The machine performs image processing for every RGB line using the reader controller PCB, and the major
functions involved are as follows:
(1) Analog Image processing
(a) CCD drive
(b) CCD output gain correction, offset correction
(c) CCD output A/D conversion
CCD (1 line each for R, G, and B)
Odd-numbered
pixel
Analog image
signal
Analog image
processing
- gain correction
- offset correction
Digital image processing block
A/D
conversion
Even-numbered
pixel
CCD drive
control
Even-numbed
pixel
Odd-numbered
conversion
pixel
CCD/AP PCB
Reader controller
PCB
Shading processing
F-6-31
J101
A12V
A5V
CCD control
signal
Gain correction
A/D
Digital image
J102
F-6-32
Chapter 6
Controller
block
J204
J204
Reader
controller
PCB
data
signal
10
J205
6-21