Ricoh B156 Service Manual page 20

White Level Correction........................................................................6-24
Others .................................................................................................6-24
Black Level Correction ........................................................................6-25
VPU Test Mode ..................................................................................6-25
6.6.3 IMAGE PROCESSING ...................................................................6-26
Shading Correction .............................................................................6-26
Picture Element (Dot Position) Correction ..........................................6-26
Scan Line Correction ..........................................................................6-26
Scanner Gamma Correction (RGB Gamma Correction) .....................6-27
Filtering ...............................................................................................6-27
ADS (Auto Image Density Selection) ..................................................6-27
Image Separation................................................................................6-28
ACS (Auto Color Selection) ................................................................6-28
Color Conversion ................................................................................6-29
Main Scan Magnification.....................................................................6-29
Printer Gamma Correction ..................................................................6-30
Error Diffusion .....................................................................................6-32
6.7 PHOTOCONDUCTOR UNIT (PCU) ........................................................6-33
6.7.1 OVERVIEW ....................................................................................6-33
6.7.2 CHARGE CORONA UNIT ..............................................................6-34
Power Supply......................................................................................6-34
Grid and Wire Cleaning.......................................................................6-34
Quenching ..........................................................................................6-35
6.7.3 OPC BELT DRIVE ..........................................................................6-36
6.7.4 OPC BELT CLEANING UNIT .........................................................6-36
Bottle Detection ..................................................................................6-36
Waste Toner Collection.......................................................................6-37
Drive ...................................................................................................6-37
6.7.5 IMAGE TRANSFER BELT UNIT ....................................................6-38
Drive ...................................................................................................6-38
Belt Mark Detection.............................................................................6-38
Transfer Roller ....................................................................................6-39
6.7.6 IMAGE TRANSFER BELT CLEANING UNIT .................................6-40
Image Transfer Belt Cleaning .............................................................6-40
Waste Toner Collection.......................................................................6-40
Set Switch and Full Sensor.................................................................6-40
Contact Mechanism ............................................................................6-41
Power Supply......................................................................................6-42
Drive ...................................................................................................6-42
6.8 LASER EXPOSURE................................................................................6-43
6.8.1 OVERVIEW ....................................................................................6-43
6.8.2 POLYGON MIRROR MOTOR UNIT...............................................6-44
Speed .................................................................................................6-44
6.8.3 SYNCHRONIZATION DETECTOR ................................................6-44
6.8.4 LD UNIT..........................................................................................6-44
6.8.5 LD SAFETY SWITCH .....................................................................6-45
Front Door...........................................................................................6-45
Circuit..................................................................................................6-45
Operation Panel Display and Switch Mechanism ...............................6-46
B156/B220
CÓPIA NÃO CONTROLADA
viii
CÓPIA NÃO CONTROLADA
SM