Potential Control - Canon imageRUNNER ADVANCE 6075 Series Service Manual

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Technology > Image Formation System > Controls > Image Stabilization Control
● Potential Control
Perform the following controls according to the deterioration level of the Photosensitive Drum
and the environmental change.
1. VD control
The primary current value (Ip) is determined to become the target dark area potential (VD).
2. VL control
The laser power (LP) is determined to become the target bright area potential (VL).
3. Vdc control
Developing bias is determined by adding the "fogging removal potential (Vback)" (based on
the environment) to the bright area potential (VL).
Execution timing
• Last rotation after the first job right after startup first time for the day takes 10 minutes or
longer
• Last rotation after processing 1,500 sheets or more following the last potential control
execution
• Last rotation after the first job following 90 minutes or more elapsed from the last potential
control execution
NOTE:
At normal startup mode (30 sec. startup), simple potential control is executed to shorten
the startup time (see Auxiliary Control > Simple Potential Control)
2 Technology > Image Formation System > Controls > Image Stabilization Control
<Control description>
1. VD control
1) The primary current (Ip_Target_Pre), which has been determined in the last potential
control *1 , is applied and the Potential Sensor measures drum surface potential (VD_Pre).
*1: At the time of installation, the primary current adjusted in the factory is applied.
2) The drum surface potential (VD_Pre) and the target potential (VD_Target) are compared to
apply the primary current (α x Ip_Target_Pre), which makes the target potential (VD_Target)
to be in range between the drum surface potential (VD_Pre) and the drum surface potential
(VDα_Pre), and then the drum surface potential (VDα_Pre) at that moment is read.
3) The 2 points of measured dark area potentials are connected with a straight line to
calculate dark area potential characteristics.
4) Based on the obtained dark area potential characteristics, the primary current (Ip_Target) is
calculated, which can obtain the target potential (VD_Target).
5) The calculated primary current is applied and this operation is repeated until the drum
surface potential (VDm) is within the range of the target potential +/- 5V. Potential
measurement is executed up to 8 times and correction is executed up to 8 times.
Voltage(V)
VD α_Pre
4)
VD_Target VD_Target±5V
3)
VD_Pre
1) 2)
Current(A)
Ip_Target_Pre
α ×Ip_Target_Pre
Ip_Target
[When the drum surface potential (VDm) is not as follows: -5V <= target potential <= +5V ]
Potential control error (VD) "E061-0101" occurs.
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Voltage(V)
5)
VDm
Current(A)
Ip_Target
F-2-99
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