Image Processing - Canon H1 Service Manual

2
Technology > Controls (Reader)
• Between sheets
The machine does not move CCD.
It reads the original using the position determined at the end or start of a job; however,
if the presence of dust is still detected at the position, the machine will execute image
correction.
0.5mm 0.5mm
A B C
Stream
reading glass
Service Mode
(Lv1) COPIER > OPTION > IMG-RDR > DFDST-L1
(used to adjust the dust detection level between sheets)
(Lv1) COPIER > OPTION > IMG-RDR > DFDST-L2
(used to adjust the dust detection level at the end of a job)
2 Technology > Controls (Reader)
Platen roller
F-2-19

■ Image Processing

● Overview
The functions of image processing system's PCB are described below.
• Main controller PCB Shading correction (executed per each job),
• CCD PCB CCD drive, analog image process, A/D conversion, A/D
conversion
The machine uses the main controller PCB to process images for every single image line.
Specific functions are as follows.
a. Main controller PCB
• Shading correction
• Color offset correction in sub scanning
b. CCD PCB (inside CCD unit)
• CCD drive
• CCD output gain correction, offset correction
CCD PCB
CCD (4lines)
Analog image
signal
EEP-ROM
CCD drive
control
Analog image
process
A/D
- gain correction
conversion
- offset correction
CCD/AP PCB
Reader controller PCB
ASIC
SRAM
Gain
Shading
correction
correction
data
CPU
Color offset
Digital
correction
image
in sub scanning
signal
F-2-20
2-11
2-11