White Plate Dust Detection Control - Canon iR7086 Series Service Manual

Chapter 5
Advise the user to clean the area where the CCD stops in stream reading if the message has appeared.
SERVICE MODE:
COPIER>OPTION>BODY>DFDST-L1 (level 1)
use it to adjust dust detection level between sheets
COPIER>OPTION>BODY>DFDST-L2 (level 1)
use it to adjust dust detection level at the end of a job

5.3.5.3 White Plate Dust Detection Control

iR7105 / iR7095 / iR7086
The white plate can collect stray dust inside the reader unit, causing lines in images, and the machine is equipped with a mechanism to check for dust on the plate
and correct it to limit its effects on output images.
Timing of Control
1. Before a Job
- white plate dust detection
- white plate dust correction
2. After a Job
- white plate dust detection
- white plate dust correction
Particulars of Control
- White Plate Dust Detection
The machine compares the data on the light reflected by the white plate at time of fixed shading and shift shading to check for dust on the white plate while at the
same time identifying the coordinates and width of the area of dust.
- White Plate Dust Correction
If the machine detects the presence of dust, it corrects the shading correction coefficient of the area of dust by means of a correction coefficient used for both sides
of the area with dust, thus limiting the effects of the dust.
5-18
B
Start key
ON
1st
SCAN
Dust detection control
C A D E
F-5-42
2nd
SCAN
Dust detection control
F-5-43
0011-2231