Canon iR3245, Service Manual

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Chapter 7
7-7
7.4 Image Stabilization Control
7.4.1 Overview
0018-9704
iR3225 / iR3225N / iR3235 / iR3235N / iR3245 / iR3245N
At times, changes in the environment or wear on the machine can cause its image output to become unstable. To obtain a stable image, the machine uses the fol-
lowing control mechanisms.
F-7-8
7.4.2 APVC Control
0018-9705
iR3225 / iR3225N / iR3235 / iR3235N / iR3245 / iR3245N
The term APVC stands for "auto primary voltage control," and it is a mechanism used to control the primary charging application voltage (DC component) to suit
the film thickness of the machine's photosensitive drum. APVC is performed every 500 sheets while the machine is in operation. It is forcibly performed when the
drum unit is replaced.
7.4.3 ATVC Control
0018-9707
iR3225 / iR3225N / iR3235 / iR3235N / iR3245 / iR3245N
The machine is provided with a constant current control mechanism that can be enabled or disabled in service mode: COPIER > OPTION > BODY > TRANS-SW.
[A] APVC control: Corrects the primary charging bias.
[B] ATVC control: Corrects the transfer bias.
[C] PASCAL control: Corrects the gradation density of an image.
[1] Primary charging roller [2] Photosensitive drum
[3] Developing assembly [4] Transfer roller
[5] Reader MN-CON: Main controller
DC-CON: DC controller
[2]
[5]
[1]
[3]
[4]
[A]
[C]
[B]
MN-CON
DC-CON