Gestetner B003 Service Manual page 19

Generation Mode ................................................................................6-33
Main scan magnification and reduction...............................................6-34
γ correction..........................................................................................6-34
Gradation processing..........................................................................6-34
Line width correction ...........................................................................6-35
6.6 LASER EXPOSURE................................................................................6-36
6.6.1 OVERVIEW ....................................................................................6-36
6.6.2 AUTO POWER CONTROL (APC) ..................................................6-37
6.6.3 DUAL BEAM WRITING ..................................................................6-38
6.6.4 LASER BEAM PITCH CHANGE MECHANISM..............................6-39
6.6.5 LD SAFETY SWITCHES ................................................................6-40
6.7 PHOTOCONDUCTOR UNIT (PCU) ........................................................6-41
6.7.1 OVERVIEW ....................................................................................6-41
6.7.2 DRIVE MECHANISM......................................................................6-42
6.7.3 DRUM PAWLS ...............................................................................6-42
6.7.4 DRUM TONER SEALS...................................................................6-42
6.8 DRUM CHARGE .....................................................................................6-43
6.8.1 OVERVIEW ....................................................................................6-43
6.8.2 CHARGE ROLLER VOLTAGE CORRECTION ..............................6-44
Correction for Environmental Conditions ............................................6-44
Correction for paper width and thickness (by-pass tray only) .............6-45
6.8.3 ID SENSOR PATTERN PRODUCTION TIMING............................6-46
6.8.4 DRUM CHARGE ROLLER CLEANING ..........................................6-46
6.9 DEVELOPMENT .....................................................................................6-47
6.9.1 OVERVIEW ....................................................................................6-47
6.9.2 DRIVE MECHANISM......................................................................6-48
6.9.3 DEVELOPER MIXING ....................................................................6-48
6.9.4 DEVELOPMENT BIAS ...................................................................6-49
Mechanism .........................................................................................6-49
Correction for paper width and thickness (by-pass tray only) .............6-49
6.9.5 TONER SUPPLY ............................................................................6-50
Toner bottle replenishment mechanism ..............................................6-50
Toner supply mechanism....................................................................6-51
Sensor Control Mode ..........................................................................6-52
Image Pixel Count Mode.....................................................................6-53
6.9.6 TONER NEAR END/END DETECTION .........................................6-53
6.9.7 TONER END RECOVERY .............................................................6-54
6.9.8 TONER SUPPLY WITH ABNORMAL SENSORS ..........................6-54
DRUM CLEANING AND TONER RECYCLING ..................................6-55
6.10.1 DRUM CLEANING........................................................................6-55
6.10.2 TONER RECYCLING ...................................................................6-55
6.11 PAPER FEED........................................................................................6-56
6.11.1 OVERVIEW ..................................................................................6-56
6.11.2 PAPER FEED DRIVE ...................................................................6-57
6.11.3 PICK-UP AND SEPARATION ROLLER RELEASE MECHANISM6-57
6.11.4 PAPER LIFT .................................................................................6-58
6.11.5 PAPER END DETECTION ...........................................................6-59
6.11.6 PAPER REGISTRATION..............................................................6-59
6.11.7 PAPER SIZE DETECTION...........................................................6-60
SM vii B003/B004/B006/B007