Ricoh LD013, Service Manual

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B039/B040/B043 vi SM
1. BiCU (Base Engine and Image Control Unit) ....................................6-6
2. IOB (I/O Board) .................................................................................6-6
3. SBU (Sensor Board Unit)..................................................................6-6
4. IMB (IMAC and Memory Board)........................................................6-6
6.3 COPY PROCESS OVERVIEW .................................................................6-7
6.4 SCANNING................................................................................................6-9
6.4.1 OVERVIEW ......................................................................................6-9
Lamp Stabilizer Fuse ............................................................................6-9
6.4.2 SCANNER DRIVE ..........................................................................6-10
6.4.3 ORIGINAL SIZE DETECTION IN PLATEN MODE.........................6-11
6.5 IMAGE PROCESSING ............................................................................6-13
6.5.1 OVERVIEW ....................................................................................6-13
6.5.2 SBU (SENSOR BOARD UNIT).......................................................6-14
6.5.3 AUTO IMAGE DENSITY (ADS) ......................................................6-15
In the SBU ..........................................................................................6-15
In the IPU............................................................................................6-15
By Original Type .................................................................................6-15
6.5.4 IPU (IMAGE PROCESSING UNIT).................................................6-16
Overview.............................................................................................6-16
Image Processing Modes ...................................................................6-17
Image Processing Path.......................................................................6-18
Original Modes....................................................................................6-19
SP Modes for Each Image Processing Step .......................................6-19
Auto Shading ......................................................................................6-21
White Line Erase ................................................................................6-22
Black Line Erase .................................................................................6-22
Scanner Gamma (
γ
) Correction ..........................................................6-23
Main Scan Magnification.....................................................................6-24
Mirroring for ADF Mode ......................................................................6-24
Filtering ...............................................................................................6-25
ID Gamma (
γ
) Correction ....................................................................6-26
Gradation Processing .........................................................................6-27
6.5.5 IMB (MEMORY CONTROLLER AND DRAM) ................................6-28
6.5.6 VIDEO CONTROL UNIT (VCU)......................................................6-29
Fine Character and Image (FCI) .........................................................6-29
Printer Gamma Correction ..................................................................6-29
6.6 LASER EXPOSURE................................................................................6-30
6.6.1 OVERVIEW ....................................................................................6-30
6.6.2 AUTO POWER CONTROL (APC) ..................................................6-31
6.6.3 LD SAFETY SWITCH .....................................................................6-32
6.7 PHOTOCONDUCTOR UNIT (PCU) ........................................................6-33
6.7.1 OVERVIEW ....................................................................................6-33
6.7.2 DRIVE.............................................................................................6-34
6.8 DRUM CHARGE .....................................................................................6-35
6.8.1 OVERVIEW ....................................................................................6-35
6.8.2 CHARGE ROLLER VOLTAGE CORRECTION ..............................6-36
Correction for Environmental Conditions ............................................6-36
6.8.3 ID SENSOR PATTERN PRODUCTION TIMING............................6-37
6.8.4 DRUM CHARGE ROLLER CLEANING ..........................................6-38