Canon IR6570 Series Service Manual page 10

Contents
4.7.5 HDD .......................................................................................................................................................... 4- 24
4.7.5.1 Removing the HDD ........................................................................................................................... 4- 24
4.7.5.2 After Replacing the HDD .................................................................................................................. 4- 24
4.7.6 Controller Fan ........................................................................................................................................... 4- 24
4.7.6.1 Removing the Controller Cooling Fan............................................................................................... 4- 24
Chapter 5 Original Exposure System
5.1 Construction....................................................................................................................................................... 5- 1
5.1.1Specifications, Controls, and Functions ...................................................................................................... 5- 1
5.1.2Major Components ...................................................................................................................................... 5- 2
5.1.3Construction of the Control System ............................................................................................................ 5- 4
5.1.4Reader Controller PCB ................................................................................................................................ 5- 5
5.2 Basic Sequence .................................................................................................................................................. 5- 7
5.2.1Basic Sequence of Operations ..................................................................................................................... 5- 7
5.2.2Basic Sequence of Operation in Response to a Press on the Start Key ....................................................... 5- 7
5.3 Various Control ................................................................................................................................................. 5- 9
5.3.1 Controlling the Scanner Drive System........................................................................................................ 5- 9
5.3.1.1 Overview.............................................................................................................................................. 5- 9
5.3.1.2 Controlling the Scanner Motor ............................................................................................................ 5- 9
5.3.2 Enlargement/Reduction ............................................................................................................................. 5- 11
5.3.2.1 Changing the Magnification in Main Scanning Direction................................................................. 5- 11
5.3.2.2 Changing the Magnification in Sub Scanning Direction ................................................................... 5- 11
5.3.3 Controlling the Scanning Lamp ................................................................................................................ 5- 13
5.3.3.1 Overview............................................................................................................................................ 5- 13
5.3.3.2 Scanning Lamp .................................................................................................................................. 5- 13
5.3.3.3 Controlling the Activation ................................................................................................................. 5- 14
5.3.4 Detecting the Size of Originals ................................................................................................................. 5- 14
5.3.4.1 Overview............................................................................................................................................ 5- 14
5.3.4.2 Points of Measurement Used for Original Size Identification........................................................... 5- 14
5.3.4.3 Overview of Operation ...................................................................................................................... 5- 16
5.3.5 Dirt Sensor Control ................................................................................................................................... 5- 19
5.3.5.1 Dust Detection in Stream Reading Mode .......................................................................................... 5- 19
5.3.5.2 White Plate Dust Detection Control .................................................................................................. 5- 21
5.3.6 Image Processing....................................................................................................................................... 5- 22
5.3.6.1 Overview............................................................................................................................................ 5- 22
5.3.6.2 CCD Drive ......................................................................................................................................... 5- 23
5.3.6.3 CCD Output Gain Correction, Offset Correction .............................................................................. 5- 24
5.3.6.4 CCD Output A/D Conversion............................................................................................................ 5- 24
5.3.6.5 Outline of Shading Correction........................................................................................................... 5- 24
5.3.6.6 Shading Adjustment........................................................................................................................... 5- 24
5.3.6.7 Shading Correction ............................................................................................................................ 5- 25
5.4 Parts Replacement Procedure .......................................................................................................................... 5- 26
5.4.1 CCD Unit................................................................................................................................................... 5- 26
5.4.1.1 Removing the Copyboard Glass ........................................................................................................ 5- 26
5.4.1.2 Removing the CCD Unit Cover......................................................................................................... 5- 26
5.4.1.3 Removing the Original Size Sensor Unit........................................................................................... 5- 27
5.4.1.4 Removing the CCD Unit.................................................................................................................... 5- 27
5.4.1.5 When Replacing the CCD Unit ......................................................................................................... 5- 27