Canon imageRUNNER ADVANCE C5500 Series Service Manual page 60

• Scanner Unit PCB
Scanner Unit drive, analog image processing, A/D conversion
Image processing is performed by the Reader Controller PCB for each line of the images. The main functions are indicated below.
1. Reader Controller PCB
• Shading correction
• Color displacement correction in vertical scanning direction
2. Scanner Unit PCB (in the Scanner Unit)
• Scanner Unit Drive
• Gain correction of the Reading Sensor output, Offset correction
Scanner Unit PCB (Reader)
LED (4lines)
Analog image
process
- gain correction
- offset correction
Scanner Unit PCB (ADF)
LED (4lines)
Analog image
process
- gain correction
- offset correction
■ Scanner Unit Drive
The Reading Sensor included in this equipment is a 4-line linear image sensor comprised of approx. 7,500 pixels. The signal
photoelectrically converted by the light-receiving part is output to the Analog Front-end Circuit on the Scanner Unit PCB with each
channel of the Reading Sensor (R, G, and B for color reading and B/W for black & white) in parallel.
Analog image
signal
Scanner unit
drive control
A/D
conversion
CCD/AP PCB
Analog image
signal
Scanner unit
drive control
A/D
conversion
CCD/AP PCB
Reader Controller PCB
ASIC
Gain
Shading
correction
correction
data
Color offset
Digital
correction
image
in sub scanning
signal
Main Controller PCB
46
2. Technology
EEP-ROM
SRAM
CPU