Atvc (Auto Transfer Voltage Control) - Konica Minolta magicolor 1690MF Service Manual

Theory of Operation Ver. 1.0 Nov. 2008
13.3.5

ATVC (Auto transfer voltage control)

• The ATVC, or Auto transfer voltage control, is for optimizing the transfer output. A con-
stant current is made to flow through each of the transfer rollers. From the voltage
thereby detected, the resistance of each of the 1st transfer roller, 2nd transfer roller, and
transfer belt is measured. The ATVC then automatically adjusts the appropriate image
transfer output voltage to be applied to the 1st transfer roller and the 2nd transfer roller
during the print cycle.
• The 1st transfer ATVC operation is performed mainly through the image stabilization con-
trol.
• The 2nd transfer ATVC operation is performed when, for example, environmental condi-
tions change during a print cycle.
A. Overview of ATVC operation
1st transfer ATVC operation
Apply the constant current the 1st
transfer Roller
Measure the resistance of the 1st
transfer Roller.
Establish the 1st transfer output
voltage.
2nd transfer ATVC operation
Apply the constant current the 2nd
transfer roller.
Measure the resistance of the 2nd
transfer roller.
Establish the 2nd transfer output
voltage.
B. 1st transfer ATVC operation
1. The data on the 1st transfer constant current for each color of toner output from the
High voltage unit (HV) is fed back to the High voltage unit via the 1st transfer roller,
transfer belt, and the photo conductor ground. The resistance of the transfer belt is
thereby measured.
2. Based on the measured resistance value, the optimum 1st transfer voltage is
established.
C. 2nd transfer ATVC operation
1. The data on the 2nd transfer constant current output from the High voltage unit
(HV) is fed back to the High voltage unit via the 2nd transfer roller, transfer belt, and
the transfer belt drive roller. The resistance of the transfer belt is thereby measured.
2. Based on the measured resistance value and inconsideration of the environmental
conditions and print color, the optimum 2nd transfer voltage is established.
Constant
voltage
Constant Measure
current resistance
2nd transfer roller
Transfer belt
Transfer belt drive roller
13. 1st transfer section
HV
Constant
current
1st transfer roller
Transfer belt
Photo conductor
ground
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