Analog Image Processing - Canon iR8500 Servise Manual

CHAPTER 2 NEW FUNCTIONS

2.2.5 Analog Image Processing

Analog image processing is performed on the CCD/AP PCB, and consists of the follow-
ing main items:
• Driving the CCD
• Executing gain correction for the CCD output, executing offset correction
• Executing A/D conversion for the CCD output
CCD
[2]
Analog image
signal
Analog signal
[4] [3]
processing block
• Gain correction
• Offset correction
Analog signal
processing block
• Gain correction
• Offset correction
CCD/AP PCB
[1] First half even-number pixel analog image signal
[2] First half odd-number pixel analog image signal
[3] Last half even-number pixel analog image signal
[4] Last half odd-number pixel analog image signal
[5] First half even-number pixel analog image signal
[6] First half odd-number image digital image signal
[7] Last half even-number pixel digital image signal
[8] Last half odd-number pixel digital image signal
2-20
[1]
CCD drive
control
[1]
A/D
conversion
[2]
A/D
conversion
[3]
A/D
conversion
[4] A/D
conversion
F02-202-03
COPYRIGHT© 2001 CANON INC.
J1501
A12V
A5V
J1502
CCD control signal
Gain/offset
correction data
2000 2000 2000 2000
J1102
J1107
Reader
controller
PCB
[5]
10bit
[6]
10
[7]
10
[8]
10
CANON iR8500 REV.0 MAR. 2001