Canon imageRUNNER C1335 Series Service Manual page 80

2
Technical Explanation > Image Formation System > Controls > Transfer/Separation
Secondary Transfer ATVC
The transfer voltage required to prevent transfer failure due to environmental changes or
paper type and to obtain the target transfer current value is set.
Control timing
1) At the same timing as the paper interval (equivalent to 80 images) during continuous
printing of the Primary Transfer ATVC
2) At initial rotation
3) At paper interval on a specified print basis (100 sheets or more)
Control description
1) Monitor current value of the secondary transfer DC bias is detected.
2) Optimal target current value is determined based on temperature/humidity data of the
Environment Sensor and paper type.
3) The secondary transfer DC bias is determined that is to be applied to the Secondary
Transfer Roller.
DC Controller PCB (UN04)
Primary Transfer
High-voltage PCB
(UN03)
Current
monitoring
signal
Primary Transfer DC
2 Technical Explanation > Image Formation System > Controls > Transfer/Separation
Environment
Sensor (UN33)
Secondary Transfer
High-voltage PCB
(UN02)
Current
Secondary
monitoring
Transfer
signal
DC
F-2-68
● Primary Transfer Bias Control
The primary transfer bias is divided into each color (Y, M, C, Bk) to be generated on the
primary transfer bias generation circuit. The primary transfer bias (TR1-1, TR1-2, TR1-3, TR1-
4), which has been generated, is applied to the Primary Transfer Roller.
The primary transfer bias value is determined by the ATVC control with the DC Controller,
which makes constant current value running though the Primary Transfer Roller.
ON and OFF of the primary transfer bias can be switched by color, and it is possible to turn
OFF the bias of the color which will not be used.
DC Controller PCB (UN04)
Primary Transfer
High-voltage PCB (UN03)
Primary Transfer DC
Primary Transfer Roller
NOTE:
The ATVC control secures transfer performance that can be affected by change in
resistance caused by the environment as well as deterioration of the Primary Transfer
Roller. The ATVC control is performed respectively for the primary transfer bias in each
color.
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F-2-69
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