Toshiba e-STUDIO555 Service Manual page 12

5.4.1 Dot matrix LCD circuit...................................................................................... 5-10
5.4.2 LED display circuit ........................................................................................... 5-11
5.5 Disassembly and Replacement....................................................................................... 5-12
6. SCANNING SECTION................................................................................................... 6-1
6.1 Function ............................................................................................................................ 6-1
6.2 Construction ...................................................................................................................... 6-2
6.3 Operation .......................................................................................................................... 6-3
6.3.1 Scanner motor (M1)........................................................................................... 6-3
6.3.2 Two-phase motor drive circuit (fixed-current type) ............................................ 6-4
6.4 Control for Exposure Lamp ............................................................................................... 6-5
6.4.1 General description............................................................................................ 6-5
6.4.2 Exposure lamp................................................................................................... 6-6
6.4.3 Control circuit for exposure lamp ....................................................................... 6-7
6.5 CCD Control...................................................................................................................... 6-8
6.5.1 Opto-electronic conversion ................................................................................ 6-8
6.5.2 Shading correction............................................................................................. 6-8
6.6 Automatic Original Size Detection Circuit ......................................................................... 6-9
6.6.1 Principle of original size detection ..................................................................... 6-9
6.6.2 Process of original size detection ...................................................................... 6-9
6.7 Disassembly and Replacement....................................................................................... 6-13
7. LASER OPTICAL UNIT ................................................................................................ 7-1
7.1 General Description .......................................................................................................... 7-1
7.2 Structure............................................................................................................................ 7-4
7.2.1 Laser optical unit................................................................................................ 7-4
7.2.2 Polygonal motor unit .......................................................................................... 7-6
7.2.3 fθ lenses 1 and 2................................................................................................ 7-8
7.2.4 H-sync detection PC board (SNS board) ........................................................... 7-8
7.2.5 Laser driving board (LDR1/LDR2 board) ........................................................... 7-8
7.2.6 Slit glass ............................................................................................................ 7-8
7.3 Laser Diode Control Circuit ............................................................................................... 7-9
7.4 Polygonal Motor Control Circuit ...................................................................................... 7-10
7.5 Laser Unit Cooling Fan Control Circuit............................................................................ 7-11
7.6 Disassembly and Replacement....................................................................................... 7-12
8. PAPER FEEDING SYSTEM.......................................................................................... 8-1
8.1 General Description .......................................................................................................... 8-1
8.2 Functions........................................................................................................................... 8-3
8.3 Operation .......................................................................................................................... 8-5
8.3.1 Operation of bypass pickup roller ...................................................................... 8-5
8.3.2 Operation of drawer pickup roller....................................................................... 8-5
8.3.3 Paper separation ............................................................................................... 8-6
8.3.4 Driving................................................................................................................ 8-7
8.3.5 General operation .............................................................................................. 8-8
8.3.6 Description of Tandem LCF Operation .............................................................. 8-9
8.4 Tray-up motor control circuit ........................................................................................... 8-12
8.5 Feed motor control circuit................................................................................................ 8-13
8.6 Transport motor control circuit ........................................................................................ 8-14
8.7 Registration motor control circuit..................................................................................... 8-15
8.8 Tandem LCF tray-up motor / end fence motor................................................................ 8-16
8.9 Disassembly and Replacement....................................................................................... 8-17
9. PROCESS RELATED SECTION .................................................................................. 9-1
9.1 Construction ...................................................................................................................... 9-1
9.2 Functions........................................................................................................................... 9-2
9.3 Charger Wire Cleaner Control Circuit ............................................................................... 9-3
9.3.1 General description............................................................................................ 9-3
9.3.2 Configuration ..................................................................................................... 9-3
9.4 High-voltage Transformer Control Circuit.......................................................................... 9-4
e-STUDIO555/655/755/855
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