Drum Film Thickness Detection - Canon Color iR C3480 Service Manual

Chapter 7
Down-time
(Max)
Condition
Return from sleep state 22 sec
*2 (approx.)
Initial rotation 10 sec
(approx.)
Printing *3 15 sec
(approx.)
Post-rotation 55 sec
(approx.)
When user-specific 100 sec
calibration is performed (approx.)
(full correction)
When user-specific 55 sec
calibration is performed (approx.)
(quick correction)
*1: The down-time interval includes the time during which the drum unit rotates idly (10 sec).
*2: This item is executed when the ongoing sleep state lasts more than 8 hr (otherwise, nothing will take place).
*3: At times, ATR control and color displacement may be executed by interrupting the ongoing print job.
MEMO:
- When the user mode "auto gradation adjustment $ full adjustment" is selected, PASCAL control, D-half control and ARCDAT control are implemented in this
order to adjust the image gradation density (full adjustment).
- When the user mode "auto gradation adjustment $ quick adjustment" is selected, D-half control and ARCDAT control are implemented in this order to adjust
image gradation density (quick adjustment).

7.3.3 Drum Film Thickness Detection

Color iR C3380G / Color iR C2880G / Color iR C3380i / Color iR C3380 / Color iR C2880i / Color iR C2880 / iR C3480 / iR C3480i / iR C3080 / iR C3080i / iR
C2550
To form an optimum image against the possible wear on the photosensitive drum, the machine checks the thickness of the drum film. The check is made for every
drum (color), and the result is recorded in EEPROM of the DC controller.
The DC controller is referred when this data detects the primary charging AC bias, the primary transfer bias, and the ATR control target value.
1. Start-Up Timing
at power-on, when closing/opening the front cover, at time of printing
2. Particulars of Control
The DC controller goes through the following to detect the thickness of the drum film:
1) computes the drum count based on "length of time during which the photosensitive drum has rotated" and "length of time during which the primary charging AC
bias is applied."
2) adds the count obtained in 1 above to the count stored in EEPROM.
3) identifies the count as indicating any of the following 3 in terms of the drum film thickness detection data based on the latest count obtained in 2 above: initial
condition, normal condition, final condition.
4) in the event of there being a difference as the result of comparison of the latest drum film thickness data against the stored drum film thickness data, the new
data is written over the existing data; in the absence of a difference, on the other hand, no write operation will take place and the new data will be discarded.
7-14
Drum film ATR control Color D-max
thickness control
detection
Yes
Yes
Yes Yes
Yes Yes
Items
Black D-max PASCAL D-half
control control control
Yes Yes
Yes Yes Yes
Yes Yes
Abridged D- Color ATVC
half control displacemen control
t control
Yes Yes Yes
Yes Yes
Yes
Yes Yes
Yes Yes
Yes Yes
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