Analog Image Processing4-4; Outline; Ii . Analog Image Processing - Canon ImageRunner 600 Service Manual

CHAPTER 4 IMAGE PROCESSING SYSTEM

II . ANALOG IMAGE PROCESSING

A.

Outline

Analog image processing takes place on the CCD PCB, which possesses the following func-
tions:
1. CCD drive
2. CCD output offset correction
3. CCD output gain correction
4. CCD output A/D conversion
5. Real-time AE processing
(ABC processing)
Data for generating sync, pulses for the reader
Communicates timing for CLK-DT reading.
When '1', the CCD turns on.
CCD PCB
CCD
Odd-numbered Even-numbered pixels
pixels
Analog signal processing block
1. Gain correction
2. Offset correction
Even-numbered pixels
Odd-numbered
pixels
A/D
conversion
8
Digital image signal
Width of an original (main
scanning direction)
Length of an original (sub
scanning direction)
4-4
COPYRIGHT © 2000 CANON INC.
Part 2>Chapter 3>1.1
Part 2>Chapter 3>1.3
Part 2>Chapter 3>1.3
Part 2>Chapter 3>1.4
Part 2>Chapter 3>2.5.1
CCD drive
control
(sync pulse
Analog image
generation)
signal
A/D
conversion
Digital image signal
8
AE
P-LNG
procession
P-WD
(ABC circuit)
When '1', the ABC circuit
executes AE.
Clock pulses for data reading
Communicates timing for AD-DT reading.
Figure 4-201 Functional Block Diagram
Clock, pulses for data reading
Main scanning sync signal
Sync clock, pulses for the reader
J1502
CCD-ON
40
CLK-LD
46
CLK-DT
47
CCD-CLK
48
HSYNC
34
30
31
35
38
39
ABC-ON
45
17
37
42
43
3
13
CANON imageRUNNER 600 REV.1 JAN. 2000 PRINTED IN U.S.A.
J1105
40
46
47
48
34
R-CLK
30
31
AD-CLK
35
AD-LD
38
AD-DT
39
45
17
37
42
43
3
13
Data for gain/
offset correction