Canon LBP5000 Series, Service Manual

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Contents
Contents
2.1 Functional Configuration ...............................................................................................................................................2-1
2.1.1 Outline.......................................................................................................................................................................................... 2-1
2.2 Basic Sequense...............................................................................................................................................................2-1
2.2.1 Basic Sequence of Operation ....................................................................................................................................................... 2-1
2.2.2 Power-On Sequence..................................................................................................................................................................... 2-1
2.3 LASER EXPOSURE SYSTEM.....................................................................................................................................2-2
2.3.1 Overview/Configuration .............................................................................................................................................................. 2-2
2.3.1.1 Outline.............................................................................................................................................................................................................2-2
2.3.2 Laser Control ............................................................................................................................................................................... 2-4
2.3.2.1 Outline.............................................................................................................................................................................................................2-4
2.3.2.2 Laser Emission Control...................................................................................................................................................................................2-4
2.3.2.3 Automatic power control (APC) .....................................................................................................................................................................2-5
2.3.2.4 Horizontal synchronous control ......................................................................................................................................................................2-5
2.3.2.5 Image Mask Control........................................................................................................................................................................................2-5
2.3.2.6 Fault Detection ................................................................................................................................................................................................2-6
2.3.3 Laser Scanner Motor Control....................................................................................................................................................... 2-6
2.3.3.1 Outline.............................................................................................................................................................................................................2-6
2.3.3.2 Speed Control..................................................................................................................................................................................................2-6
2.3.3.3 Phase Control ..................................................................................................................................................................................................2-6
2.3.3.4 Fault Detection ................................................................................................................................................................................................2-7
2.4 IMAGE FORMATION SYSTEM .................................................................................................................................2-7
2.4.1 Overview/Configuration .............................................................................................................................................................. 2-7
2.4.1.1 Outline.............................................................................................................................................................................................................2-7
2.4.1.2 Image Formation Process................................................................................................................................................................................2-8
2.4.1.3 Electrostatic latent image formation block .....................................................................................................................................................2-9
2.4.1.4 Developing block ..........................................................................................................................................................................................2-10
2.4.1.5 Transfer block ...............................................................................................................................................................................................2-11
2.4.1.6 Fixing block ..................................................................................................................................................................................................2-12
2.4.1.7 Drum cleaning block .....................................................................................................................................................................................2-12
2.4.2 High-Voltage Control ................................................................................................................................................................ 2-13
2.4.2.1 Outline...........................................................................................................................................................................................................2-13
2.4.2.2 Outline...........................................................................................................................................................................................................2-13
2.4.2.3 Generation of the Primary Charging Bias.....................................................................................................................................................2-14
2.4.2.4 Generation of the Developing Bias ...............................................................................................................................................................2-14
2.4.2.5 Generation of the Transfer Bias ....................................................................................................................................................................2-14
2.4.2.6 Generation of the Fixing Bias .......................................................................................................................................................................2-15
2.4.2.7 Electrostatic eliminate bias ...........................................................................................................................................................................2-15
2.4.2.8 ETB drive roller bias.....................................................................................................................................................................................2-15
2.4.3 Image Stabilizaton Control ........................................................................................................................................................ 2-15
2.4.3.1 Overview of the Image Stabilization Control Mechanism............................................................................................................................2-15
2.4.3.2 Environment corrective control.....................................................................................................................................................................2-15
2.4.3.3 Image density corrective control (D-max control)........................................................................................................................................2-15
2.4.3.4 Image halftone corrective control (D-half control).......................................................................................................................................2-16
2.4.3.5 Image density detection control ....................................................................................................................................................................2-16
2.4.3.6 Overview of Color Misregistration Corrective Control ...............................................................................................................................2-16
2.4.3.7 Color misregistration detection .....................................................................................................................................................................2-16
2.4.4 Toner Cartridge.......................................................................................................................................................................... 2-17
2.4.4.1 Outline...........................................................................................................................................................................................................2-17
2.4.4.2 Memory Tag Control.....................................................................................................................................................................................2-18
2.4.4.3 Detection of Toner cartridge presence/absence ............................................................................................................................................2-18
2.4.4.4 Detecting the End of Life of the Cartridge....................................................................................................................................................2-18
2.4.4.5 Detecting the Level of Toner ........................................................................................................................................................................2-19
2.4.5 Transfer Unit.............................................................................................................................................................................. 2-19
2.4.5.1 ETB Unit .......................................................................................................................................................................................................2-19