Ricoh D009 Service Manual page 21

DETAILED SECTION DESCRIPTIONS
6. DETAILED SECTION DESCRIPTIONS ....................................... 6-1
6.1 OVERVIEW ................................................................................................6-1
6.1.1 COMPONENT LAYOUT ....................................................................6-1
6.2 BOARD STRUCTURE................................................................................6-5
6.2.1 BLOCK DIAGRAM.............................................................................6-5
6.3 COPY PROCESS .......................................................................................6-9
6.3.1 OVERVIEW .......................................................................................6-9
6.4 SCANNING...............................................................................................6-11
6.4.1 OVERVIEW .....................................................................................6-11
6.4.2 SCANNER DRIVE ...........................................................................6-12
6.4.3 ORIGINAL SIZE DETECTION IN PLATEN MODE..........................6-13
6.5 IMAGE PROCESSING .............................................................................6-15
6.5.1 OVERVIEW .....................................................................................6-15
6.5.2 SBU (SENSOR BOARD UNIT)........................................................6-16
6.5.3 AUTO IMAGE DENSITY (ADS).......................................................6-18
6.5.4 IPU (IMAGE PROCESSING UNIT) .................................................6-19
6.5.5 IMAGE PROCESSING MODES ......................................................6-19
6.5.6 SUMMARY OF IMAGE PROCESSING FUNCTIONS .....................6-19
6.5.7 IMAGE PROCESSING STEPS .......................................................6-20
6.5.8 INDEPENDENT DOT ERASE .........................................................6-21
6.6 LASER EXPOSURE .................................................................................6-23
6.6.1 OVERVIEW .....................................................................................6-23
6.6.2 AUTO POWER CONTROL (APC)...................................................6-24
6.6.3 LD SAFETY SWITCHES .................................................................6-24
6.7 AROUND THE DRUM ..............................................................................6-25
6.7.1 OVERVIEW .....................................................................................6-25
6.7.2 DRUM CLEANING ..........................................................................6-26
6.7.3 DRIVE MECHANISM.......................................................................6-27
6.7.4 DRUM PAWLS ................................................................................6-27
6.8 DRUM CHARGE.......................................................................................6-28
6.8.1 OVERVIEW .....................................................................................6-28
6.8.2 CHARGE ROLLER VOLTAGE CORRECTION ...............................6-29
6.8.3 ID SENSOR PATTERN PRODUCTION TIMING.............................6-31
6.8.4 DRUM CHARGE ROLLER CLEANING ...........................................6-31
6.9 DEVELOPMENT ......................................................................................6-32
SM ix D009/D011/D012/D013