Canon iR2020 Series Service Manual page 185

Contents
6.1 Construction ...................................................................................................................................................................6-1
6.1.1 Specifications of Image Formation System ................................................................................................................................. 6-1
6.1.2 Major Components of Image Formation System......................................................................................................................... 6-1
6.2 Image Formation Process...............................................................................................................................................6-1
6.2.1 Image Formation Process............................................................................................................................................................. 6-1
6.3 Basic Sequence ..............................................................................................................................................................6-2
6.3.1 Basic Sequence of Operation ....................................................................................................................................................... 6-2
6.4 Driving and Controlling the High-Voltage System .......................................................................................................6-3
6.4.1 Outline.......................................................................................................................................................................................... 6-3
6.5 Drum Unit ......................................................................................................................................................................6-4
6.5.1 Outline of the Drum Unit ............................................................................................................................................................. 6-4
6.5.1.1 Outline.............................................................................................................................................................................................................6-4
6.5.2 Charging Mechanism ................................................................................................................................................................... 6-4
6.5.2.1 Primary Charging Bias Control.......................................................................................................................................................................6-4
6.6 Developing Unit.............................................................................................................................................................6-5
6.6.1 Outline.......................................................................................................................................................................................... 6-5
6.6.2 Developing Bias Control.............................................................................................................................................................. 6-5
6.7 Toner Container .............................................................................................................................................................6-6
6.7.1 Outline.......................................................................................................................................................................................... 6-6
6.8 Transfer Unit ..................................................................................................................................................................6-6
6.8.1 Outline of the Transfer Unit......................................................................................................................................................... 6-6
6.8.1.1 Outline.............................................................................................................................................................................................................6-6
6.8.2 Controlling the Transfer Bias....................................................................................................................................................... 6-7
6.8.2.1 Transfer Roller Bias Control ...........................................................................................................................................................................6-7
6.8.3 Separation Mechanism................................................................................................................................................................. 6-7
6.8.3.1 Static Eliminator Bias Control ........................................................................................................................................................................6-7
6.9 Photosensitive Drum Cleaning.......................................................................................................................................6-8
6.9.1 Outline.......................................................................................................................................................................................... 6-8
6.9.2 Waste Toner Full Detection ......................................................................................................................................................... 6-8
6.10 Parts Replacement Procedure.......................................................................................................................................6-9
6.10.1 Drum Unit .................................................................................................................................................................................. 6-9
6.10.1.1 Removing the Drum Unit..............................................................................................................................................................................6-9
6.10.2 Developing Assembly ................................................................................................................................................................ 6-9
6.10.2.1 Removing the Drum Unit..............................................................................................................................................................................6-9
6.10.2.2 Removing the Rear Cover .............................................................................................................................................................................6-9
6.10.2.3 Removing the Right Cover (Lower) .............................................................................................................................................................6-9
6.10.2.4 Removing the Delivery Tray.........................................................................................................................................................................6-9
6.10.2.5 Removing the Developing Assembly............................................................................................................................................................6-9
6.10.2.6 Precautions about Installation of Developing Assembly ...........................................................................................................................6-10
6.10.2.7 Procedure after Replacing the Developing Assembly ................................................................................................................................6-10
6.10.3 Transfer Charging Roller ......................................................................................................................................................... 6-10
6.10.3.1 Removing the Transfer Charging Roller.....................................................................................................................................................6-10
Contents