Konica Minolta 5430 DL 5440 DL 5450 - Manual (Page 70)

Main Unit Theory of Operation Toner Cartridge / Developing Unit
2-33
II Comp
osition
/O
p
eration
7.2.4 Developing bias Vpp control (Ds compensation control)
• If the developing bias voltage AC component (Vpp) is too high for the Ds distance in each
Toner Cartridge, a leak image (background leak, image area leak) or halftone reproduc-
tion failure results.
• As a means for preventing this phenomenon, this control detects a Vpp range, in which
no image failure occurs, to set the optimum Vpp.
• The Vpp control may be either the simplified check or complete correction.
• The developing bias Vpp is controlled integrally with other control items by the image sta-
bilization control.
• The developing bias Vpp control is performed when there is a request made for execu-
tion of image stabilization sequence.
☞ 2-120
A. Simplified check
1.
The leak decision criterion value is measured.
2. A leak decision is made based on the data acquired during the last complete correction
control.
3. If it is determined that there is no leak occurring, the last Vpp value is applied.
4. If it is determined that there is a leak occurring, the control proceeds to the complete
correction and the Vpp correction procedure is performed.
B. Complete correction control
1.
The leak decision criterion value is measured.
2. The Vpp value for the leak decision is detected.
3. The leak marginal value is detected.
4. Calculate and determine the set Vpp value based on the leak marginal value.
Simplified check Complete correction control
Start
Measure the leak criterion value.
Perform leak margin check.
Determine whether it is necessary
to shift to Vpp correction.
End
4138to2134e0
Start
Measure the leak criterion value.
Detect the marginal Vpp value.
Determine the set Vpp value.
End
4138to2135e0
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