5.3.3.1 Overview .................................................................................................................................................................................. 5- 8

5.3.3.2 Scanning Lamp ........................................................................................................................................................................ 5- 9

5.3.3.3 Controlling the Activation ......................................................................................................................................................... 5- 9

5.3.4 Detecting the Size of Originals.................................................................................................................................5- 9

5.3.4.1 Overview .................................................................................................................................................................................. 5- 9

5.3.4.2 Points of Measurement Used for Original Size Identification................................................................................................... 5- 9

5.3.4.3 Overview of Operation ........................................................................................................................................................... 5- 11

5.3.5 Dirt Sensor Control ................................................................................................................................................5- 13

5.3.5.1 Dust Detection in Stream Reading Mode............................................................................................................................... 5- 13

5.3.5.2 White Plate Dust Detection Control ....................................................................................................................................... 5- 14

5.3.6 Image Processing ..................................................................................................................................................5- 15

5.3.6.1 Overview ................................................................................................................................................................................ 5- 15

5.3.6.2 CCD Drive.............................................................................................................................................................................. 5- 16

5.3.6.3 CCD Output Gain Correction, Offset Correction .................................................................................................................... 5- 17

5.3.6.4 CCD Output A/D Conversion ................................................................................................................................................. 5- 17

5.3.6.5 Outline of Shading Correction................................................................................................................................................ 5- 17

5.3.6.6 Shading Adjustment............................................................................................................................................................... 5- 17

5.3.6.7 Shading Correction ................................................................................................................................................................ 5- 17

5.4 Parts Replacement Procedure ................................................................................................................. 5- 19

5.4.1 CCD Unit................................................................................................................................................................5- 19

5.4.1.1 Removing the Copyboard Glass ............................................................................................................................................ 5- 19

5.4.1.2 Removing the CCD Unit Cover .............................................................................................................................................. 5- 19

5.4.1.3 Removing the Original Size Sensor Unit................................................................................................................................ 5- 19

5.4.1.4 Removing the CCD Unit......................................................................................................................................................... 5- 20

5.4.1.5 When Replacing the CCD Unit .............................................................................................................................................. 5- 20

5.4.2 Copyboard glass ....................................................................................................................................................5- 20

5.4.2.1 Removing Copyboard Glass .................................................................................................................................................. 5- 20

5.4.2.2 When Replacing the Platen Board Glass............................................................................................................................... 5- 20

5.4.3 Scanning Lamp ......................................................................................................................................................5- 20

5.4.3.1 Removing the Copyboard Glass ............................................................................................................................................ 5- 20

5.4.3.2 Removing the Right Cover (upper) ........................................................................................................................................ 5- 21

5.4.3.3 Removing the Reader Right Cover ........................................................................................................................................ 5- 21

5.4.3.4 Removing the Left Cover (upper)........................................................................................................................................... 5- 21

5.4.3.5 Removing the Reader Left Cover .......................................................................................................................................... 5- 21

5.4.3.6 Removing the Reader Front Cover ........................................................................................................................................ 5- 22

5.4.3.7 Removing the Reader Unit Rear Cover ................................................................................................................................. 5- 22

5.4.3.8 Removing the CCD Unit Cover .............................................................................................................................................. 5- 23

5.4.3.9 Removing the Scanning Lamp............................................................................................................................................... 5- 23

5.4.3.10 When Replacing the Scanning Lamp................................................................................................................................... 5- 24

5.4.4 Reader Controller PCB ..........................................................................................................................................5- 24

5.4.4.1 Removing the Copyboard Glass ............................................................................................................................................ 5- 24

5.4.4.2 Removing the CCD Unit Cover .............................................................................................................................................. 5- 24

5.4.4.3 Removing the Original Size Sensor Unit................................................................................................................................ 5- 25

5.4.4.4 Removing the Reader Controller PCB ................................................................................................................................... 5- 25

5.4.4.5 After Replacing the Reader Controller PCB........................................................................................................................... 5- 25

5.4.5 Interface PCB.........................................................................................................................................................5- 26

5.4.5.1 Removing the Reader Unit Rear Cover ................................................................................................................................. 5- 26

5.4.5.2 Removing the Interface PCB ................................................................................................................................................. 5- 26

5.4.6 Inverter PCB ..........................................................................................................................................................5- 27

5.4.6.1 Removing the Copyboard Glass ............................................................................................................................................ 5- 27

5.4.6.2 Removing the CCD Unit Cover .............................................................................................................................................. 5- 28

5.4.6.3 Removing the Inverter PCB ................................................................................................................................................... 5- 28

5.4.6.4 When Replacing the Inverter PCB ......................................................................................................................................... 5- 28

5.4.7 Scanner Motor .......................................................................................................................................................5- 28

5.4.7.1 Removing the Reader Unit Rear Cover ................................................................................................................................. 5- 28

5.4.7.2 Removing the Scanner Motor ................................................................................................................................................ 5- 29

5.4.7.3 Mounting the Scanner Motor.................................................................................................................................................. 5- 30

5.4.8 ADF Open/Close Sensor .......................................................................................................................................5- 30

5.4.8.1 Removing the Reader Unit Rear Cover ................................................................................................................................. 5- 30

5.4.8.2 Removing the ADF Open/Closed Sensor .............................................................................................................................. 5- 31

Table of Contents