Canon imageRUNNER ADVANCE 6075 Series, Service Manual

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Technology > Image Formation System > Controls > Image Stabilization Control
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 pot/- 10V. Potential
measurement is executed up to 8 times and correction is executed up to 8 times.
VLm VL_Target
±10V
EPC_LP_Target
VL_Target
β×EPC_LP_Target_Pre
VL
β
_Pre
LP_Target_Pre
VL_Pre
VI
(V)
1) 2)
4)
3)
EPC_LP_Target
5)
Laser power relative value(%)
F-2-100
[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 (/-
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.
NOTE:
With this machine, laser APC control is executed to correct the bright area potential
between sheets and jobs (see Auxiliary Control > Laser APC Control)
Lp is actually calculated by the laser power (LP) and the bright area potential characteristics
that were obtained in the last VL control because executing VL control each time takes time.
When the bright area potential measured value fails to be within the range of the target
pot/- 10V, follow the workflow as described below to obtain bright area potential
characteristics by the foregoing VL control to calculate LP.