Canon iR C6800 Series Service Manual page 10

Contents
Chapter 6 Laser Exposure
6.1 Construction........................................................................................................................................................ 6 1
6.1.1 Specifications, Control Mechanisms, and Functions................................................................................... 6 1
6.1.2 Major Components ...................................................................................................................................... 6 2
6.1.3 Construction of the Control System ............................................................................................................ 6 3
6.2 Basic Sequence ................................................................................................................................................... 6 4
6.2.1 Basic Sequence of Operation....................................................................................................................... 6 4
6.3 Various Control .................................................................................................................................................. 6 5
6.3.1 Controlling the Laser Activation Timing ..................................................................................................... 6 5
6.3.2 Controlling the Intensity of Laser Light....................................................................................................... 6 8
6.3.3 Controlling the Laser Scanner Motor........................................................................................................... 6 9
6.3.4 Controlling the Laser Shutter ..................................................................................................................... 6 10
6.4 Parts Replacement Procedure ........................................................................................................................... 6 11
6.4.1 Laser Scanner Unit ..................................................................................................................................... 6 11
Chapter 7 Image Formation
7.1 Construction........................................................................................................................................................ 7 1
7.1.1 Specifications of the Image Formation System ........................................................................................... 7 1
7.1.2 Major Components ...................................................................................................................................... 7 4
7.1.3 Charging System.......................................................................................................................................... 7 5
7.2 Image Formation Process ................................................................................................................................... 7 7
7.2.1 Image Formation Process ............................................................................................................................ 7 7
7.3 Basic Sequence ................................................................................................................................................... 7 9
7.3.1 At Time of Power On .................................................................................................................................. 7 9
7.3.2 During Copying/Printing (normal speed) .................................................................................................. 7 10
7.3.3 During Copying/Printing (2/3 speed, 1/3 speed) ....................................................................................... 7 10
7.4 Image Stabilization Control.............................................................................................................................. 7 11
7.4.1 Overview of Image Stabilization Control.................................................................................................. 7 11
7.4.2 Timing of Image Stabilization Control...................................................................................................... 7 12
7.4.3 Potential Control ........................................................................................................................................ 7 15
7.4.4 ATVC Control ........................................................................................................................................... 7 19
7.4.5 ATR Control .............................................................................................................................................. 7 21
7.4.6 ACR Control (Auto Carrier Refresh Control) ........................................................................................... 7 24
7.4.7 D max Control ........................................................................................................................................... 7 25
7.4.8 D half Control............................................................................................................................................ 7 26
7.4.9 PASCAL control ....................................................................................................................................... 7 29
7.5 Charging Meachanism ...................................................................................................................................... 7 32
7.5.1 Controlling the Primary Charging Bias ..................................................................................................... 7 32
7.5.2 Controlling the Primary Charging Assembly Cleaning Mechanism ......................................................... 7 33
7.5.3 Controlling the Pre Transfer Charging Bias.............................................................................................. 7 34
7.5.4 Controlling the Pre Transfer Charging Assembly Cleaning Mechanism.................................................. 7 34
7.5.5 Pre Exposure LED..................................................................................................................................... 7 36
7.6 Developing Rotary............................................................................................................................................ 7 37
7.6.1 Overview of the Developing Rotary.......................................................................................................... 7 37
7.6.2 Controlling the Developing Rotary ........................................................................................................... 7 38
7.7 Developing Unit................................................................................................................................................ 7 41
7.7.1 Construction of the Color Developing Assembly...................................................................................... 7 41
7.7.2 Controlling the Color Developing Assembly Drive Mechanism .............................................................. 7 42
7.7.3 Controlling the Color Developing Bias ..................................................................................................... 7 43
7.7.4 Color Toner Supply ................................................................................................................................... 7 44
7.7.5 Detecting the Level of Color Toner........................................................................................................... 7 45
7.7.6 Construction of the Black Developing Assembly ..................................................................................... 7 48