Canon LBP-3000, Service Manual

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Contents
Contents
2.1 Functional Configuration ...............................................................................................................................................2-1
2.1.1 Outline.......................................................................................................................................................................................... 2-1
2.2 Basic Sequense...............................................................................................................................................................2-2
2.2.1 Basic Operation Sequence ........................................................................................................................................................... 2-2
2.2.2 Power-on sequence ...................................................................................................................................................................... 2-2
2.3 LASER EXPOSURE SYSTEM.....................................................................................................................................2-3
2.3.1 Overview/Configuration .............................................................................................................................................................. 2-3
2.3.1.1 Overview .........................................................................................................................................................................................................2-3
2.3.2 Controlling the Laser Activation Timing..................................................................................................................................... 2-3
2.3.2.1 Turning On/Off the Laser................................................................................................................................................................................2-3
2.3.2.2 Horizontal Synchronization Control ...............................................................................................................................................................2-4
2.3.3 Laser Control ............................................................................................................................................................................... 2-4
2.3.3.1 Auto Photo Current Control ............................................................................................................................................................................2-4
2.3.4 Laser Scanner Motor Control....................................................................................................................................................... 2-5
2.3.4.1 Outline.............................................................................................................................................................................................................2-5
2.3.4.2 Scanner Motor Speed Control.........................................................................................................................................................................2-5
2.3.4.3 Detection of a Fault in the Scanner Motor ......................................................................................................................................................2-5
2.4 IMAGE FORMATION SYSTEM .................................................................................................................................2-6
2.4.1 Overview/Configuration .............................................................................................................................................................. 2-6
2.4.1.1 Construction ....................................................................................................................................................................................................2-6
2.4.1.2 Printing Process...............................................................................................................................................................................................2-6
2.4.1.3 Latent Image Formation Block .......................................................................................................................................................................2-7
2.4.1.4 Development Block.........................................................................................................................................................................................2-8
2.4.1.5 Transfer Block.................................................................................................................................................................................................2-9
2.4.1.6 Fixing Block..................................................................................................................................................................................................2-10
2.4.1.7 Drum Cleaning Block ...................................................................................................................................................................................2-11
2.4.2 High-Voltage Control ................................................................................................................................................................ 2-11
2.4.2.1 Outline...........................................................................................................................................................................................................2-11
2.4.2.2 Generation of the Primary Charging Bias.....................................................................................................................................................2-12
2.4.2.3 Generation of the Developing Bias ...............................................................................................................................................................2-12
2.4.2.4 Generation of the Transfer Charging Bias ....................................................................................................................................................2-12
2.4.3 Toner Cartridge.......................................................................................................................................................................... 2-13
2.4.3.1 Checking the Presence/Absence of a Toner Cartridge..................................................................................................................................2-13
2.4.3.2 Checking the Level of Toner.........................................................................................................................................................................2-13
2.5 PICKUP AND FEEDING SYSTEM...........................................................................................................................2-14
2.5.1 Overview/Configuration ............................................................................................................................................................ 2-14
2.5.1.1 Outline...........................................................................................................................................................................................................2-14
2.5.2 Detecting Jams ........................................................................................................................................................................... 2-14
2.5.2.1 Jam Detection Outline...................................................................................................................................................................................2-14
2.5.2.1.1 Outline...................................................................................................................................................................................................2-14
2.5.2.2 Delay Jams ....................................................................................................................................................................................................2-15
2.5.2.2.1 Pickup Delay Jam..................................................................................................................................................................................2-15
2.5.2.2.2 Delivery Delay Jam...............................................................................................................................................................................2-15
2.5.2.3 Stationary Jams .............................................................................................................................................................................................2-15
2.5.2.3.1 Pickup Stationary Jam...........................................................................................................................................................................2-15
2.5.2.3.2 Delivery Stationary Jam........................................................................................................................................................................2-15
2.5.2.4 Other Jams.....................................................................................................................................................................................................2-15
2.5.2.4.1 Wrapping Jam Around the Fixing Assembly........................................................................................................................................2-15
2.5.2.4.2 Residual Jam at Start-Up.......................................................................................................................................................................2-15
2.5.2.4.3 Door Open Jam......................................................................................................................................................................................2-15
2.5.3 Multi-purpose Pickup................................................................................................................................................................. 2-15
2.5.3.1 Pickup from the Pickup Tray/Manual Feed Tray..........................................................................................................................................2-15
2.6 EXTERNAL AND CONTROLS SYSTEM ................................................................................................................2-17