Canon GP605 Service Manual page 11

CHAPTER 5 LASER EXPOSURE SYSTEM
I. OPERATIONS ............................ 5-1
A. Outline .................................... 5-1
B. Basic Sequence of Operations
(laser exposure system) ........ 5-4
II. GENERATING THE BD SIGNAL 5-5
A. Outline .................................... 5-5
B. Flow of the BD Signal ............ 5-5
III. LASER DRIVER PCB ................. 5-7
A. Outline .................................... 5-7
B. Controlling the Laser Activation
............................................... 5-8
C. Controlling the Laser Intensity
............................................. 5-10
CHAPTER 6 IMAGE FORMATION SYSTEM
I . PROCESSES .............................. 6-1
A. Outline .................................... 6-1
B. Basic Sequence of Operations
(image formation) ................... 6-3
II . POTENTIAL CONTROL ............. 6-5
A. Outline .................................... 6-5
B. Determining the Optimum Grid
Bias ........................................ 6-8
C. Grid Bias Corrective Control .. 6-8
D. Determining the Optimum Laser
Output .................................... 6-9
E. Laser Output Corrective control
............................................... 6-9
F. Determining the Optimum
Developing Bias ................... 6-10
G. Potential Control for
Transparency Mode ............. 6-11
H. Target Potential Correction in
Each Mode ........................... 6-12
1. Adjusting the Density during
Printing (PDL input) ........ 6-13
2. Potential Control during High
Humidity Mode ................ 6-14
3. Density Adjustment during
Printing (scanner input) .. 6-15
III . CONTROLLING THE CHARGING
MECHANISMS .......................... 6-16
A. Controlling the Primary Charging
Mechanism........................... 6-16
1. Outline ............................ 6-16
COPYRIGHT © 1999 CANON INC. CANON GP605/605V REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
IV. Controlling the Laser Scanner Motor
.................................................. 5-12
A. Outline .................................. 5-12
V. DISASSEMBLY/ASSEMBLY .... 5-13
A. Laser Unit............................. 5-14
1. Removing the Laser Unit
........................................ 5-14
2. After Replacing the Laser Unit
........................................ 5-15
B. BD Unit ................................. 5-16
1. Removing the BD Unit .... 5-16
2. Changing the Primary
Charging Level Setting ... 6-17
3. Primary Charging Assembly
Cleaning Mechanism ...... 6-18
4. Others ............................. 6-19
B. Dust-Collecting Roller Bias .. 6-20
1. Outline ............................ 6-20
C. Controlling the Pre-Transfer
Charging Mechanism ........... 6-21
1. Outline ............................ 6-21
2. Controlling the Output to Suit
the Environment (fuzzy
control) ............................ 6-22
3. Pre-Transfer Charging
Assembly Cleaning
Mechanism ..................... 6-23
4. Others ............................. 6-24
D. Controlling the Transfer Guide
Bias ...................................... 6-25
1. Outline ............................ 6-25
2. Controlling the Output to Suit
the Environment ............. 6-26
E. Controlling the Transfer Charging
Mechanism........................... 6-27
1. Outline ............................ 6-27
2. Controlling the Output to Suit
the Environment (fuzzy
control) ............................ 6-28
3. Correcting the Output at the
Trailing Edge of Paper .... 6-29
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