Canon iR5055 Series Service Manual page 181

Contents
7.1 Construction ...................................................................................................................................................................7-1
7.1.1 Overview...................................................................................................................................................................................... 7-1
7.1.2 Major Components....................................................................................................................................................................... 7-1
7.2 Image Formation Process...............................................................................................................................................7-1
7.2.1 Overview...................................................................................................................................................................................... 7-1
7.3 Basic Sequence ..............................................................................................................................................................7-2
7.3.1 At Power-On ................................................................................................................................................................................ 7-2
7.3.2 At Time of Printing ...................................................................................................................................................................... 7-3
7.4 Potential Control ............................................................................................................................................................7-3
7.4.1 Overview...................................................................................................................................................................................... 7-3
7.4.2 Copier/Printer Potential Control .................................................................................................................................................. 7-3
7.4.3 Determining the Primary Current ................................................................................................................................................ 7-6
7.4.4 Determining the Laser Output ..................................................................................................................................................... 7-6
7.4.5 Determining the Developing Bias................................................................................................................................................ 7-6
7.4.6 APC Correction............................................................................................................................................................................ 7-7
7.4.7 Adjusting the Density in Various Modes..................................................................................................................................... 7-7
7.5 Charging Mechanism .....................................................................................................................................................7-8
7.5.1 Controlling Pre-Exposure LED.................................................................................................................................................... 7-8
7.5.1.1 Pre-Exposure LED Control .............................................................................................................................................................................7-8
7.5.2 Primary Charging Mechanism ..................................................................................................................................................... 7-9
7.5.2.1 Overview .........................................................................................................................................................................................................7-9
7.5.2.2 Primary Charging Assembly Cleaning Mechanism ........................................................................................................................................7-9
7.5.2.3 Others ............................................................................................................................................................................................................7-10
7.5.3 Dust-Collecting Roller Bias ....................................................................................................................................................... 7-10
7.5.3.1 Overview .......................................................................................................................................................................................................7-10
7.5.4 Pre-Transfer Charging Mechanism............................................................................................................................................ 7-11
7.5.4.1 Overview .......................................................................................................................................................................................................7-11
7.5.4.2 Controlling the Output to Suit the Environment (fuzzy control) ..................................................................................................................7-11
7.5.4.3 Pre-Transfer Charging Assembly Cleaning Mechanism...............................................................................................................................7-12
7.5.4.4 Others ............................................................................................................................................................................................................7-12
7.6 Drum Cleaner Unit.......................................................................................................................................................7-12
7.6.1 Overview.................................................................................................................................................................................... 7-12
7.6.2 Detecting the State (full) of the Collecting Toner Case............................................................................................................. 7-13
7.6.3 Drum/Separation Claw Bias Control ......................................................................................................................................... 7-14
7.7 Developing Assembly ..................................................................................................................................................7-14
7.7.1 Controlling the Developing Assembly Drive ............................................................................................................................ 7-14
7.7.2 Controlling the Developing Bias ............................................................................................................................................... 7-14
7.7.3 Detecting the Toner Level and Controlling Toner Supply ........................................................................................................ 7-15
7.8 Transfer Mechanism ....................................................................................................................................................7-16
7.8.1 Transfer Charging Mechanism .................................................................................................................................................. 7-16
7.8.1.1 Overview .......................................................................................................................................................................................................7-16
7.8.1.2 Controlling the Output to Suit the Environment (fuzzy control) ..................................................................................................................7-16
7.8.1.3 Transfer Charging Assembly Cleaning Mechanism .....................................................................................................................................7-17
7.8.1.4 Others ............................................................................................................................................................................................................7-17
7.9 Separation Mechanism .................................................................................................................................................7-18
7.9.1 Separation Charging Mechanism ............................................................................................................................................... 7-18
7.9.1.1 Overview .......................................................................................................................................................................................................7-18
7.9.1.2 Correcting the Output to Suit the Environment and the Drum Surface Potential .........................................................................................7-18
7.9.1.3 Others ............................................................................................................................................................................................................7-19
7.10 Parts Replacement Procedure.....................................................................................................................................7-20
7.10.1 Process Unit ............................................................................................................................................................................. 7-20
Contents