Gestetner B003 Service Manual page 18

DETAILED DESCRIPTIONS
6 DETAILED SECTION DESCRIPTIONS ....................................... 6-1
6.1 OVERVIEW ...............................................................................................6-1
6.1.1 COMPONENT LAYOUT ...................................................................6-1
6.1.2 PAPER PATH...................................................................................6-3
6.1.3 DRIVE LAYOUT ...............................................................................6-4
6.2 BOARD STRUCTURE...............................................................................6-5
6.2.1 BLOCK DIAGRAM............................................................................6-5
6.2.2 CONTROLLER .................................................................................6-7
6.3 COPY PROCESS OVERVIEW .................................................................6-9
Exposure...............................................................................................6-9
Drum charge .........................................................................................6-9
Laser exposure .....................................................................................6-9
Development.........................................................................................6-9
Image transfer.....................................................................................6-10
Separation ..........................................................................................6-10
ID sensor ............................................................................................6-10
Cleaning..............................................................................................6-10
Quenching ..........................................................................................6-10
6.4.1 OVERVIEW ....................................................................................6-11
SCANNER DRIVE ..............................................................................6-12
Book Mode..........................................................................................6-12
ADF mode...........................................................................................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) ......................................................6-17
6.5.4 IPU (IMAGE PROCESSING UNIT).................................................6-18
Overview.............................................................................................6-18
6.5.5 IMAGE PROCESSING MODES .....................................................6-19
6.5.6 SUMMARY OF IMAGE PROCESSING FUNCTIONS ....................6-21
6.5.7 IMAGE PROCESSING STEPS AND RELATED SP MODES.........6-22
Text Mode...........................................................................................6-22
Text/Photo Mode ................................................................................6-23
Photo Mode ........................................................................................6-24
Pale (Low-Density Mode)....................................................................6-25
Generation Copy Mode.......................................................................6-26
Auto shading (shading correction) ......................................................6-27
Background erase...............................................................................6-27
Independent dot erase ........................................................................6-28
Filtering ...............................................................................................6-29
Pre-Filter .............................................................................................6-29
Text Mode...........................................................................................6-30
Photo Mode ........................................................................................6-31
Text/Photo Mode ................................................................................6-32
Low Density Mode ..............................................................................6-33
B003/B004/B006/B007 vi SM