Canon ImageRunner iR8500 Series Service Manual page 337

Contents
8.1 Construction ...................................................................................................................................................................8-1
8.1.1 Outline.......................................................................................................................................................................................... 8-1
8.1.2 Outline of the Image Formation System(iR105) ......................................................................................................................... 8-1
8.1.3 Major Components....................................................................................................................................................................... 8-3
8.1.4 Pre-Transfer Exposure LED ........................................................................................................................................................ 8-4
8.1.5 Pre-Transfer Exposure LED ........................................................................................................................................................ 8-4
8.1.6 Pre-Transfer Exposure LED ........................................................................................................................................................ 8-4
8.1.7 Pre-Transfer Exposure LED ........................................................................................................................................................ 8-5
8.1.8 Addition of the Developing Fan(iR105) ...................................................................................................................................... 8-5
8.2 Basic Sequence ..............................................................................................................................................................8-6
8.2.1 Basic Sequence ............................................................................................................................................................................ 8-6
8.2.2 Basic Sequence ............................................................................................................................................................................ 8-6
8.3 Potential Control ............................................................................................................................................................8-7
8.3.1 Outline.......................................................................................................................................................................................... 8-7
8.3.2 Basic Sequence ............................................................................................................................................................................ 8-7
8.3.3 Basic Sequence ............................................................................................................................................................................ 8-8
8.3.4 Determining the Optimum Grid Bias........................................................................................................................................... 8-9
8.3.5 Grid Bias Corrective Control ....................................................................................................................................................... 8-9
8.3.6 Determining the Optimum Laser Output ................................................................................................................................... 8-10
8.3.7 Laser Output Corrective Control ............................................................................................................................................... 8-10
8.3.8 Determining the Optimum Developing Bias ............................................................................................................................. 8-11
8.3.9 Potential Control for Transparency Mode ................................................................................................................................. 8-11
8.3.10 Target Potential Correction in Each Mode .............................................................................................................................. 8-12
8.3.11 Target Potential Correction in Each Mode .............................................................................................................................. 8-14
8.4 Charging Mechanism ...................................................................................................................................................8-16
8.4.1 Primary Charging Mechanism ................................................................................................................................................... 8-16
8.4.1.1 Outline...........................................................................................................................................................................................................8-16
8.4.1.2 Primary Charging Assembly Cleaning Mechanism ......................................................................................................................................8-16
8.4.1.3 Others ............................................................................................................................................................................................................8-17
8.4.2 Dust-Collecting Roller Bias ....................................................................................................................................................... 8-17
8.4.2.1 Outline...........................................................................................................................................................................................................8-17
8.4.3 Pre-Transfer Charging Mechanism............................................................................................................................................ 8-18
8.4.3.1 Outline...........................................................................................................................................................................................................8-18
8.4.3.2 Controlling the Output to Suit the Environment (fuzzy control) ..................................................................................................................8-19
8.4.3.3 Pre-Transfer Charging Assembly Cleaning Mechanism...............................................................................................................................8-20
8.4.3.4 Others ............................................................................................................................................................................................................8-20
8.5 Drum Cleaner Unit.......................................................................................................................................................8-22
8.5.1 Outline........................................................................................................................................................................................ 8-22
8.5.2 Outline........................................................................................................................................................................................ 8-22
8.5.3 Detecting the Waste Toner (case full condition) ....................................................................................................................... 8-23
8.6 Developing Assembly ..................................................................................................................................................8-25
8.6.1 Outline........................................................................................................................................................................................ 8-25
8.6.2 Controlling the Developing Assembly....................................................................................................................................... 8-25
8.6.3 Controlling the Toner Cartridge Drive Mechanism................................................................................................................... 8-26
8.6.4 Controlling the Developing Bias ............................................................................................................................................... 8-27
8.6.5 Detecting the Toner Level and Controlling the Toner Supply Mechanism............................................................................... 8-28
8.7 Transfer Mechanism ....................................................................................................................................................8-31
8.7.1 Transfer Guide Bias ................................................................................................................................................................... 8-31
8.7.1.1 Outline...........................................................................................................................................................................................................8-31
8.7.1.2 Controlling the Output to Suit the Environment ...........................................................................................................................................8-31
8.7.2 Transfer Charging Mechanism .................................................................................................................................................. 8-32
Contents