7.1 Construction ...................................................................................................................................................................7-1

7.1.1 Outline.......................................................................................................................................................................................... 7-1

7.1.2 Major Components....................................................................................................................................................................... 7-1

7.1.3 Pre-Transfer Exposure LED ........................................................................................................................................................ 7-2

7.2 Image Formation Process...............................................................................................................................................7-2

7.2.1 Overview...................................................................................................................................................................................... 7-2

7.3 Basic Sequence ..............................................................................................................................................................7-3

7.3.1 Basic Sequence ............................................................................................................................................................................ 7-3

7.4 Potential Control ............................................................................................................................................................7-3

7.4.1 Outline.......................................................................................................................................................................................... 7-3

7.4.2 Basics Sequence of Operations .................................................................................................................................................... 7-4

7.4.3 Determining the Optimum Grid Bias........................................................................................................................................... 7-5

7.4.4 Grid Bias Corrective Control ....................................................................................................................................................... 7-6

7.4.5 Determining the Optimum Laser Output ..................................................................................................................................... 7-6

7.4.6 Laser Output Corrective Control ................................................................................................................................................. 7-7

7.4.7 Determining the Optimum Developing Bias ............................................................................................................................... 7-7

7.4.8 Potential Control for Transparency Mode ................................................................................................................................... 7-8

7.4.9 Target Potential Correction in Each Mode .................................................................................................................................. 7-9

7.5 Charging Mechanism ...................................................................................................................................................7-11

7.5.1 Primary Charging Mechanism ................................................................................................................................................... 7-11

7.5.1.1 Outline...........................................................................................................................................................................................................7-11

7.5.1.2 Primary Charging Assembly Cleaning Mechanism ......................................................................................................................................7-12

7.5.1.3 Others ............................................................................................................................................................................................................7-13

7.5.2 Dust-Collecting Roller Bias ....................................................................................................................................................... 7-13

7.5.2.1 Outline...........................................................................................................................................................................................................7-13

7.5.3 Pre-Transfer Charging Mechanism............................................................................................................................................ 7-14

7.5.3.1 Outline...........................................................................................................................................................................................................7-14

7.5.3.2 Controlling the Output to Suit the Environment (fuzzy control) ..................................................................................................................7-15

7.5.3.3 Pre-Transfer Charging Assembly Cleaning Mechanism...............................................................................................................................7-16

7.5.3.4 Others ............................................................................................................................................................................................................7-16

7.6 Drum Cleaner Unit.......................................................................................................................................................7-17

7.6.1 Outline........................................................................................................................................................................................ 7-17

7.6.2 Detecting the Waste Toner (case full condition) ....................................................................................................................... 7-17

7.7 Developing Assembly ..................................................................................................................................................7-18

7.7.1 Outline........................................................................................................................................................................................ 7-18

7.7.2 Controlling the Developing Assembly....................................................................................................................................... 7-19

7.7.3 Controlling the Toner Cartridge Drive Mechanism................................................................................................................... 7-20

7.7.4 Controlling the Developing Bias ............................................................................................................................................... 7-21

7.7.5 Detecting the Toner Level and Controlling the Toner Supply Mechanism............................................................................... 7-22

7.8 Transfer Mechanism ....................................................................................................................................................7-25

7.8.1 Transfer Guide Bias ................................................................................................................................................................... 7-25

7.8.1.1 Overview .......................................................................................................................................................................................................7-25

7.8.1.2 Controlling the Output to Suit the Environment ...........................................................................................................................................7-26

7.8.2 Transfer Charging Mechanism .................................................................................................................................................. 7-26

7.8.2.1 Outline...........................................................................................................................................................................................................7-26

7.8.2.2 Controlling the Output to Suit the Environment (fuzzy control) ..................................................................................................................7-27

7.8.2.3 Correcting the Output at the Trailing Edge of Paper ....................................................................................................................................7-28

7.8.2.4 Transfer Charging Assembly Cleaning Mechanism .....................................................................................................................................7-28

7.8.2.5 Others ............................................................................................................................................................................................................7-29

7.9 Separation Mechanism .................................................................................................................................................7-29

7.9.1 Separation Charging Mechanism ............................................................................................................................................... 7-29

Contents

Table of Contents