HP Color LaserJet Enterprise MFP M680 series - Page 8

Fuser sleeve temperature protection .......................................................... 20
Failure detection .......................................................................................... 21
Fuser unit identification ............................................................................... 22
Fuser unit life detection ............................................................................... 22
Laser/scanner system ......................................................................................................................................... 23
Laser/scanner failure ........................................................................................................................ 24
Protective-glass cleaners ................................................................................................................. 25
Image-formation system .................................................................................................................................... 26
Image formation process .................................................................................................................. 28
Step 1: Pre-exposure ...................................................................................................... 29
Step 2: Primary charging ................................................................................................ 29
Step 3: Laser-beam exposure ........................................................................................ 30
Step 4: Development ...................................................................................................... 30
Step 5: Primary transfer ................................................................................................. 31
Step 6: Secondary transfer ............................................................................................. 31
Step 7: Separation .......................................................................................................... 32
Step 8: Fusing .................................................................................................................. 32
Step 9: ITB cleaning ........................................................................................................ 33
Step 10: Drum cleaning .................................................................................................. 33
Toner cartridges ................................................................................................................................ 34
Memory tag ..................................................................................................................... 35
Developing unit engagement and disengagement control ........................................... 35
Intermediate transfer belt (ITB) unit ................................................................................................ 37
Primary transfer roller engagement and disengagement control ................................ 37
ITB cleaning mechanism ................................................................................................. 40
Calibration ......................................................................................................................................... 40
Color-misregistration control ........................................................................................ 41
Image stabilization control ............................................................................................. 42
Pickup, feed, and delivery system ...................................................................................................................... 43
Pickup-and-feed unit ........................................................................................................................ 48
Cassette pickup ............................................................................................................... 48
Cassette-presence detection ....................................................................... 49
Cassette lift operation and cassette paper-presence detection ................ 50
Cassette multiple-feed prevention .............................................................. 51
Multipurpose tray pickup ................................................................................................ 51
Paper feed ....................................................................................................................... 52
Skew-feed prevention .................................................................................. 54
Paper detection ............................................................................................ 55
Feed speed control ....................................................................................... 55
Fusing and delivery block ................................................................................................................. 56
Loop control .................................................................................................................... 57
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