Chapter 7
7-20
7.4.2 Automatic Bias Control
0019-8977
imageCLASS MF9170c / imageCLASS MF9150c / imageCLASS MF8450c
Depending on the individual difference or deterioration condition of the transfer roller, attraction roller, and ETB, differences and changes occur in the resistance
value of each unit. In this condition, a transfer failure may occur when an expected level of bias is not applied to each roller.
This control is executed to apply the optimum level of bias to each roller based on the measured voltage of each roller.
The DC controller sends a constant current to the transfer roller (Bk) and attraction roller when starting print operation and measures the voltage at that point. Based
on the measured voltage, it extracts the optimum transfer and attraction biases.
In the subsequent print operation, the optimum transfer and attraction biases are applied to stabilize the image quality.
F-7-25
a. Transfer roller voltage detection
b. Attraction roller voltage detection
ETB engaged roller
ETB
Attraction roller
Current
Constant current
V
Voltage
detection
Constant current
Current
Transfer roller (Bk)
ETB
Photosensitive drum (Bk)
V
Voltage
detection
Summary of Contents for imageCLASS MF9170c
Page 16: ...Chapter 1 Introduction ...
Page 55: ...Chapter 2 Basic Operation ...
Page 61: ...Chapter 3 Main Controller ...
Page 75: ...Chapter 4 Original Exposure System ...
Page 88: ...Chapter 5 Original Feeding System ...
Page 105: ...Chapter 6 Laser Exposure ...
Page 113: ...Chapter 7 Image Formation ...
Page 150: ...Chapter 8 Pickup and Feed System ...
Page 184: ...Chapter 9 Fixing System ...
Page 200: ...Chapter 10 External and Controls ...
Page 230: ...Chapter 11 Maintenance and Inspection ...
Page 233: ...Chapter 12 Measurement and Adjustments ...
Page 237: ...Chapter 13 Correcting Faulty Images ...
Page 260: ...Chapter 14 Error Code ...
Page 272: ...Chapter 15 Special Management Mode ...
Page 280: ...Chapter 16 Service Mode ...
Page 322: ...Chapter 17 Upgrading ...
Page 327: ...Chapter 17 17 4 3 Click Next F 17 4 4 Select a USB connected device and click Next F 17 5 ...
Page 328: ...Chapter 17 17 5 5 Click Start F 17 6 6 Click Yes F 17 7 Download will be started F 17 8 ...
Page 330: ...Chapter 18 Service Tools ...
Page 334: ...Appendix ...
Page 349: ......