
Chapter 8
8-15
1. Potential Control during High Humidity Mode
F-8-23
WMUPR
WMUP
STBY
195˚C
200˚C
Potential sensor
Laser
Grid bias
Vg
Pw
VD
VL
Potential determined
Vg
Pw
Vdc
Extra low humidity
Low humidity
Normal humidity
High humidity
-5%
+5%
+20V
+30V
Density
Darker
Lighter
In a low humidity environment,
the resistance of paper
decreases and, on the other
hand, the transfer efficiency
increases; as such, the laser
power is reduced to prevent
excess deposit of toner.
In a high humidity environment,
the moisture of paper decreases
the transfer efficiency; as such,
the laser power is increased to
increase the density.
Laser power
correction
value
Vdc
correction
value
VD
correction
value
Extra high humidity
Potential control
sequence started
The laser power/Vdc is corrected
to suit the environment.
Summary of Contents for ImageRunner iR8500 Series
Page 1: ...Apr 5 2005 Service Manual iR8500 Series ...
Page 2: ......
Page 6: ......
Page 32: ...Contents ...
Page 33: ...Chapter 1 Introduction ...
Page 34: ......
Page 98: ......
Page 99: ...Chapter 2 Installation ...
Page 100: ......
Page 180: ...Chapter 2 2 78 F 2 272 2 1 1 3 ...
Page 181: ...Chapter 3 Basic Operation ...
Page 182: ......
Page 184: ......
Page 207: ...Chapter 4 Main Controller ...
Page 208: ......
Page 245: ...Chapter 4 4 35 F 4 72 1 2 ...
Page 246: ......
Page 247: ...Chapter 5 Original Exposure System ...
Page 248: ......
Page 252: ......
Page 306: ......
Page 307: ...Chapter 6 Image Processing System ...
Page 308: ......
Page 310: ......
Page 319: ...Chapter 7 Laser Exposure ...
Page 320: ......
Page 322: ......
Page 335: ...Chapter 8 Image Formation ...
Page 336: ......
Page 340: ......
Page 399: ...Chapter 9 Pickup Feeding System ...
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Page 483: ...Chapter 10 Fixing System ...
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Page 525: ...Chapter 11 External and Controls ...
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Page 583: ...Chapter 12 MEAP ...
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Page 589: ...Chapter 13 Maintenance and Inspection ...
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Page 610: ...Chapter 13 13 18 F 13 17 1 2 3 ...
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Page 649: ...Chapter 14 Standards and Adjustments ...
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Page 723: ...Chapter 15 Correcting Faulty Images ...
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Page 793: ...Chapter 16 Self Diagnosis ...
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Page 841: ...Chapter 17 Service Mode ...
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Page 1077: ...Chapter 18 Upgrading ...
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Page 1108: ...Chapter 18 18 28 F 18 45 3 Click Start F 18 46 4 Click Save F 18 47 5 Click OK ...
Page 1111: ...Chapter 19 Service Tools ...
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Page 1121: ...Apr 5 2005 ...
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