Ricoh Aficio 1027 - Page 5

ii
MTF Filter ...........................................................................................2-17
Smoothing Filter..................................................................................2-17
Characteristic Filter.............................................................................2-17
Independent Dot Erase.......................................................................2-18
Background Erase ..............................................................................2-18
ID Gamma (γ) Correction ....................................................................2-18
Gradation Processing .........................................................................2-18
Overview.............................................................................................2-18
Grayscale Processing.........................................................................2-19
Binary Picture Processing...................................................................2-19
Error Diffusion.....................................................................................2-19
Dithering .............................................................................................2-19
Line width correction...........................................................................2-19
2.2.5 VIDEO CONTROL UNIT (VCU)......................................................2-20
Fine Character and Image (FCI).........................................................2-20
2.3 LASER EXPOSURE................................................................................2-21
2.3.1 OVERVIEW ....................................................................................2-21
2.3.2 AUTO POWER CONTROL (APC)..................................................2-22
2.3.3 LD SAFETY SWITCH.....................................................................2-23
2.4 PHOTOCONDUCTOR UNIT (PCU) ........................................................2-24
2.4.1 OVERVIEW ....................................................................................2-24
2.4.2 DRIVE.............................................................................................2-25
2.4.3 NEW PCU DETECTION.................................................................2-26
2.5 DRUM CHARGE .....................................................................................2-27
2.5.1 OVERVIEW ....................................................................................2-27
2.5.1 CHARGE ROLLER VOLTAGE CORRECTION..............................2-28
Correction for Environmental Conditions ............................................2-28
2.5.2 ID SENSOR PATTERN PRODUCTION TIMING............................2-29
2.5.3 DRUM CHARGE ROLLER CLEANING..........................................2-30
2.6 DEVELOPMENT .....................................................................................2-31
2.6.1 OVERVIEW ....................................................................................2-31
2.6.2 DRIVE.............................................................................................2-32
2.6.3 DEVELOPER MIXING....................................................................2-33
2.6.4 DEVELOPMENT BIAS ...................................................................2-34
2.6.5 TONER SUPPLY............................................................................2-35
Toner bottle replenishment mechanism..............................................2-35
Toner supply mechanism....................................................................2-36
2.6.6 TONER DENSITY CONTROL........................................................2-37
Overview.............................................................................................2-37
Toner density sensor initial setting......................................................2-39
Toner density measurement ...............................................................2-39
Vsp/Vsg detection...............................................................................2-39
Toner supply reference voltage (Vref) determination..........................2-39
Toner supply determination ................................................................2-39
Toner Supply Motor On Time Determinations.....................................2-40
2.6.7 TONER SUPPLY IN ABNORMAL SENSOR CONDITIONS...........2-41
ID sensor ............................................................................................2-41
TD Sensor...........................................................................................2-41
2.6.8 TONER NEAR END/END DETECTION AND RECOVERY............2-41