Canon imagePRESS C1 P, Service Manual, Page: 291 / 1265

Chapter 5
5-12
F-5-27
*: Only executes in the case of detecting dust at all reading points when the previous job is processed. In the case of detecting dust at all reading points, the dust
correction is executed before reading to regard the less-dust position as the original reading position.
2. Control Description
(1) When the job is finished (change the dust reading position at stream reading)
Detect the reflection from the surface of the feeding belt (white color) at the reading reference position [A] to detect presence/absence of dust. In the case of
detecting dust, shift to the following positions (maximum 7 points: A to B to C to D to E to F to G).
The position that does not detect dust will be the reading point for the next job.
F-5-28
[1] dust
[2] black line
- In the case of detecting dust at all reading positions, display the alarm screen to encourage cleaning when setting the original to the ADF.
- When a job is started, execute dust detection again to regard the dust-free position or the less-dust position as the reading position.
(2) At paper interval (dust correction)
There is no shift of the xenon lamp due to dust detection.
In the case of detecting dust at paper interval, dust correction is executed by compensating the dust area with the pixels at both edges.
MEMO:
COPIER > OPTION > BODY > DFDST-L1 (level 1)
(Adjusting dust reading detection level at paper interval)
COPIER > OPTION > BODY > DFDST-L2 (level 1)
(Adjusting dust reading detection level when the job is finished)
5.3.5.2 White Plate Dust Detection Control
0012-9683
imagePRESS C1 / Color Image Reader-H1 / imagePRESS C1+ (Printer) / imagePRESS C1+
The machine uses a fan to cool the inside of the reader unit to prevent overheating otherwise caused by the xenon lamp in stream reading mode. The fact, however,
can cause stray dust inside the reader unit to collect on the white plate, showing up as lines in output images.
1. Timing of Control
(1) Before a Job
Dust Detection
Control* Dust Detection
Control Dust Detection
Control
Start key
ON
1st
SCAN 2nd
SCAN
G F E A D C B
3mm
0.5
mm 0.5
mm 0.5
mm 0.5
mm 0.5
mm 0.5
mm
[1]
[2]