Vl Control - Canon imageRUNNER ADVANCE 8105 Series Service Manual

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Technology > Image Formation System > Controls > Image Stabilization Control

2. VL control

1) The laser power (LP_Target_Pre), which has been determined in the last bright area
potential control*1, is applied and the Potential Sensor measures the drum surface
potential (VL_Pre).
*1: At the time of installation, the primary current adjusted in the factory is applied.
2) The drum surface potential (VL_Pre) and the target potential (VL_Target) are
compared to apply the primary current (β x EPC_LP_Target_Pre), which makes the
target potential (VL_Target) to be in range between the drum surface potential (VL_Pre)
and the drum surface potential (VLβ_Pre), and then the drum surface potential
(VLβ_Pre) at that moment is read.
3) The 2 points of measured bright area potentials are connected with a straight line to
calculate the bright area potential characteristics.
4) Based on the obtained bright area potential characteristics, the laser power
(EPC_LP_Target) is calculated, which can obtain the target potential (VL_Target).
5) The Drum is exposed with the calculated laser power and this operation is repeated
until the drum surface potential (VLm) is within the range of the target potential +/-
10V. Potential measurement is executed up to 8 times and correction is executed up
to 8 times.
β
VL _Pre
3)
4)
VL_Target
VL_Pre
2) 1)
EPC_LP_Target
β×EPC_LP_Target_Pre
LP_Target_Pre
Laser power relative value(%)
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Technology > Image Formation System > Controls > Image Stabilization Control
5)
VL_Target±10V VLm
EPC_LP_Target
F-2-101 F-2-101
[When the drum surface potential is not as follows: -10V <= target potential <= +10V ]
•
When the drum surface potential is as follows: -10V > target potential > -30V or +10V <
target potential < +30V
The laser power (LP) when the previous potential control was succeeded (within
+/-10V target potential) is applied. Refer to the alarm code "32-0002" for the
processing when the image is influenced.
•
When the target potential is as follows: target potential <= -30V or target potential >= +30V
Potential control error (VL) "E061-0001" occurs.
MEMO
With this machine, laser APC control is executed to correct the bright area
potential between sheets and jobs (see Auxiliary Control > Laser APC Control)
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