Dust Detection Correction Control; Image Processing - Canon imageRUNNER 1750 Series Service Manual

2
Technical Explanation > Original Exposure and Feed System > Controls > Image Processing

■ Dust Detection Correction Control

Whenever the original from the ADF is read, presence or absence of duct is detected at the
original read position determined in the dust detection preventive process. If presence of dust
is detected, the image correction process is performed to prevent dust from appearing in the
output image.
Main power
switch ON Start key ON
WMUPR STBY
Dust detection
correction control
2 Technical Explanation > Original Exposure and Feed System > Controls > Image Processing
1st 2nd
SCAN SCAN
Dust detection Dust detection
correction control correction control
F-2-29

■ Image Processing

● Overview
Major specifications and functions of the image processing system are as follows:
• Original reading sensor array Number of lines: 1
Number of pixels: Total 5148 (incl. 5104 effective pixels)
• Shading correction Shading correction: Performed for each job.
Shading adjustment: Performed in the Service mode.
Contact image
sensor (CIS) Reader controller PCB
Analog image processor
Original reading
sensor
Analog
image
conversion
processing
About image processing, the function of the reader controller PCB is as follows:
• Original reading sensor drive
• Original reading sensor output gain correction and offset correction
• Original reading sensor output A/D conversion
• Shading correction
• LED intensity adjustment
Digital image processor
Main
Shading
A/D controller
processing
PCB
2-18
F-2-30
2-18