Canon iR7086, Service Manual

Page: 185 / 735

Contents
Contents
5.1 Construction ...................................................................................................................................................................5-1
5.1.1 Specifications, Controls, and Functions....................................................................................................................................... 5-1
5.1.2 Specifications, Controls, and Functions....................................................................................................................................... 5-2
5.1.3 Major Components....................................................................................................................................................................... 5-3
5.1.4 Major Components....................................................................................................................................................................... 5-4
5.1.5 Construction of the Control System............................................................................................................................................. 5-6
5.1.6 Construction of the Control System............................................................................................................................................. 5-6
5.2 Basic Sequence ..............................................................................................................................................................5-7
5.2.1 Basic Sequence of Operations ..................................................................................................................................................... 5-7
5.2.2 Basic Sequence of Operations ..................................................................................................................................................... 5-7
5.2.3 Basic Sequence of Operation in Response to a Press on the Start Key ....................................................................................... 5-7
5.2.4 Basic Sequence of Operation in Response to a Press on the Start Key ....................................................................................... 5-8
5.3 Various Control..............................................................................................................................................................5-8
5.3.1 Controlling the Scanner Drive System ........................................................................................................................................ 5-8
5.3.1.1 Overview .........................................................................................................................................................................................................5-8
5.3.1.2 Controlling the Scanner Motor........................................................................................................................................................................5-9
5.3.1.3 Controlling the Scanner Motor......................................................................................................................................................................5-10
5.3.2 Enlargement/Reduction.............................................................................................................................................................. 5-10
5.3.2.1 Changing the Reproduction Ratio in Main Scanning Direction ...................................................................................................................5-10
5.3.2.2 Changing the Reproduction Ratio in Sub Scanning Direction......................................................................................................................5-11
5.3.2.3 Changing the Reproduction Ratio in Sub Scanning Direction......................................................................................................................5-11
5.3.3 Controlling the Scanning Lamp ................................................................................................................................................. 5-11
5.3.3.1 Overview .......................................................................................................................................................................................................5-11
5.3.3.2 Overview .......................................................................................................................................................................................................5-11
5.3.3.3 Scanning Lamp..............................................................................................................................................................................................5-11
5.3.3.4 Controlling the Activation.............................................................................................................................................................................5-12
5.3.4 Detecting the Size of Originals .................................................................................................................................................. 5-12
5.3.4.1 Overview .......................................................................................................................................................................................................5-12
5.3.4.2 Points of Measurement Used for Original Size Identification ......................................................................................................................5-12
5.3.4.3 Overview of Operation..................................................................................................................................................................................5-14
5.3.4.4 Overview of Operation..................................................................................................................................................................................5-15
5.3.5 Dirt Sensor Control .................................................................................................................................................................... 5-16
5.3.5.1 Dust Detection in Stream Reading Mode......................................................................................................................................................5-16
5.3.5.2 Dust Detection in Stream Reading Mode......................................................................................................................................................5-17
5.3.5.3 White Plate Dust Detection Control..............................................................................................................................................................5-18
5.3.6 Image Processing ....................................................................................................................................................................... 5-19
5.3.6.1 Overview .......................................................................................................................................................................................................5-19
5.3.6.2 Overview .......................................................................................................................................................................................................5-20
5.3.6.3 CCD Drive ....................................................................................................................................................................................................5-21
5.3.6.4 CCD Drive ....................................................................................................................................................................................................5-21
5.3.6.5 CCD Output Gain Correction, Offset Correction .........................................................................................................................................5-22
5.3.6.6 CCD Output A/D Conversion .......................................................................................................................................................................5-22
5.3.6.7 Outline of Shading Correction ......................................................................................................................................................................5-22
5.3.6.8 Shading Adjustment ......................................................................................................................................................................................5-22
5.3.6.9 Shading Correction........................................................................................................................................................................................5-22
5.4 Parts Replacement Procedure.......................................................................................................................................5-23
5.4.1 CCD Unit ................................................................................................................................................................................... 5-23
5.4.1.1 Before Starting the Work ..............................................................................................................................................................................5-23
5.4.1.2 Removing the CCD Unit ...............................................................................................................................................................................5-23
5.4.1.3 When Replacing Components of the Scanning System ................................................................................................................................5-23
5.4.1.4 When Replacing Components of the Scanning System ................................................................................................................................5-23
5.4.2 Copyboard glass......................................................................................................................................................................... 5-23
5.4.2.1 Removing the Copyboard Glass....................................................................................................................................................................5-23