Ricoh A230 Service Manual page 3

2.3.1 OVERVIEW ................................................................................... 2-22
2.3.2 OPTICAL PATH ............................................................................. 2-23
2.3.3 AUTO POWER CONTROL (APS) ................................................. 2-24
2.3.4 DUAL BEAM WRITING.................................................................. 2-25
2.3.5 LASER BEAM PITCH CHANGE MECHANISM ............................. 2-26
2.3.6 LD SAFETY SWITCHES ............................................................... 2-27
2.4 PHOTOCONDUCTOR UNIT (PCU)........................................................ 2-28
2.4.1 OVERVIEW ................................................................................... 2-28
2.4.2 DRIVE MECHANISM ..................................................................... 2-29
2.5 DRUM CHARGE..................................................................................... 2-30
2.5.1 OVERVIEW ................................................................................... 2-30
2.5.2 CHARGE ROLLER VOLTAGE CORRECTION ............................. 2-31
Correction for environmental conditions............................................. 2-31
Correction for paper width and thickness (bypass tray only) .............. 2-32
2.5.3 ID SENSOR PATTERN PRODUCTION TIMING ........................... 2-33
2.5.4 DRUM CHARGE ROLLER CLEANING ......................................... 2-33
2.6 DEVELOPMENT..................................................................................... 2-34
2.6.1 OVERVIEW ................................................................................... 2-34
2.6.2 DRIVE MECHANISM ..................................................................... 2-35
2.6.3 DEVELOPER MIXING ................................................................... 2-36
2.6.4 DEVELOPMENT BIAS................................................................... 2-37
Correction for paper width and thickness (bypass tray only) .............. 2-37
2.6.5 TONER SUPPLY ........................................................................... 2-38
Toner bottle replenishment mechanism ............................................. 2-38
Toner supply mechanism ................................................................... 2-39
2.6.6 TONER DENSITY CONTROL ....................................................... 2-40
Overview ............................................................................................ 2-40
Toner density control flow chart ......................................................... 2-40
Sensor control mode .......................................................................... 2-41
Image Pixel Count Control Mode. ...................................................... 2-42
2.6.7 TONER NEAR END/END DETECTION......................................... 2-43
Toner near end/end detection flow chart............................................ 2-43
2.6.8 TONER END RECOVERY............................................................. 2-45
Toner end recovery flow chart............................................................ 2-45
2.6.9 TONER SUPPLY IN ABNORMAL SENSOR CONDITIONS .......... 2-46
2.7 DRUM CLEANING AND TONER RECYCLING...................................... 2-47
2.7.1 DRUM CLEANING......................................................................... 2-47
2.7.2 TONER RECYCLING .................................................................... 2-48
2.8 PAPER FEED ......................................................................................... 2-49
2.8.1 OVERVIEW ................................................................................... 2-49
2.8.2 PAPER FEED DRIVE MECHANISM ............................................. 2-50
2.8.3 PICK-UP AND SEPARATION ROLLER RELEASE MECHANISM 2-51
2.8.4 PAPER LIFT MECHANISM............................................................ 2-52
2.8.5 PAPER END DETECTION............................................................. 2-54
2.8.6 PAPER REGISTRATION............................................................... 2-55
2.8.7 PAPER FEED AND JAM TIMING .................................................. 2-56
2.9 IMAGE TRANSFER AND PAPER SEPARATION .................................. 2-57
2.9.1 OVERVIEW ................................................................................... 2-57
2.9.2 BELT DRIVE MECHANISM ........................................................... 2-58
A230/A231/A232
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