Canon imageRUNNER 5065 series Service Manual page 12

Contents
Chapter 7 Image Formation
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- 2
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- 5
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- 8
7.5.2.1 Overview .................................................................................................................................................................................. 7- 8
7.5.2.2 Primary Charging Assembly Cleaning Mechanism.................................................................................................................. 7- 9
7.5.2.3 Others ...................................................................................................................................................................................... 7- 9
7.5.3 Dust-Collecting Roller Bias ....................................................................................................................................7- 10
7.5.3.1 Overview ................................................................................................................................................................................ 7- 10
7.5.4 Pre-Transfer Charging Mechanism........................................................................................................................7- 10
7.5.4.1 Overview ................................................................................................................................................................................ 7- 10
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- 11
7.5.4.4 Others .................................................................................................................................................................................... 7- 11
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- 12
7.6.3 Drum/Separation Claw Bias Control ......................................................................................................................7- 13
7.7 Developing Assembly ............................................................................................................................... 7- 13
7.7.1 Controlling the Developing Assembly Drive...........................................................................................................7- 13
7.7.2 Controlling the Developing Bias.............................................................................................................................7- 13
7.7.3 Detecting the Toner Level and Controlling Toner Supply ......................................................................................7- 14
7.8 Transfer Mechanism................................................................................................................................. 7- 15
7.8.1 Transfer Charging Mechanism...............................................................................................................................7- 15
7.8.1.1 Overview ................................................................................................................................................................................ 7- 15
7.8.1.2 Controlling the Output to Suit the Environment (fuzzy control) .............................................................................................. 7- 15
7.8.1.3 Transfer Charging Assembly Cleaning Mechanism............................................................................................................... 7- 16
7.8.1.4 Others .................................................................................................................................................................................... 7- 16
7.9 Separation Mechanism............................................................................................................................. 7- 17
7.9.1 Separation Charging Mechanism...........................................................................................................................7- 17
7.9.1.1 Overview ................................................................................................................................................................................ 7- 17
7.9.1.2 Correcting the Output to Suit the Environment and the Drum Surface Potential ................................................................... 7- 17
7.9.1.3 Others .................................................................................................................................................................................... 7- 18
7.10 Parts Replacement Procedure ............................................................................................................... 7- 19
7.10.1 Process Unit.........................................................................................................................................................7- 19
7.10.1.1 Before Removing Process Unit ............................................................................................................................................ 7- 19
7.10.1.2 Removing Process Unit ....................................................................................................................................................... 7- 19
7.10.1.3 Mounting Process Unit ........................................................................................................................................................ 7- 19
7.10.2 Pre-Exposure Lamp .............................................................................................................................................7- 20