5.3.4.2 Overview .......................................................................................................................................... 5- 11

5.3.4.3 Activation Control............................................................................................................................ 5- 11

5.3.4.4 Error Detection ................................................................................................................................ 5- 11

5.3.5 Detecting the Size of Originals............................................................................................................. 5- 11

5.3.5.1 Overview .......................................................................................................................................... 5- 11

5.3.5.2 Points of Original Size Detection.................................................................................................. 5- 13

5.3.5.3 Overview of Detection Operation ................................................................................................. 5- 13

5.3.6 Dirt Sensor Control................................................................................................................................. 5- 15

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

5.3.7 Image Processing................................................................................................................................... 5- 17

5.3.7.1 Overview .......................................................................................................................................... 5- 17

5.3.7.2 Driving the CCD .............................................................................................................................. 5- 18

5.3.7.3 Gain Correction and Offset Correction for the CCD Output..................................................... 5- 18

5.3.7.4 A/D Conversion of the CCD Output ............................................................................................. 5- 18

5.3.7.5 Shading Correction (outline) ......................................................................................................... 5- 19

5.3.7.6 Shading Adjustment ....................................................................................................................... 5- 19

5.3.7.7 Shading Correction......................................................................................................................... 5- 19

5.4 Parts Replacement Procedure ................................................................................................................... 5- 20

5.4.1 Copyboard Glass.................................................................................................................................... 5- 20

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

5.4.1.2 After Replacing the Copyboard Glass ......................................................................................... 5- 20

5.4.1.3 Removing the ADF Reading Glass.............................................................................................. 5- 21

5.4.1.4 After Replacing the ADF Reading Glass..................................................................................... 5- 21

5.4.2 Reader Controller PCB.......................................................................................................................... 5- 22

5.4.2.1 Before Replacing the Reader Controller PCB............................................................................ 5- 22

5.4.2.2 Before Removing the Reader Controller PCB ........................................................................... 5- 22

5.4.2.3 Removing the Reader Controller PCB ........................................................................................ 5- 22

5.4.2.4 After Replacing the Reader Controller PCB ............................................................................... 5- 23

5.4.3 Inverter PCB............................................................................................................................................ 5- 24

5.4.3.1 Before Removing the Inverter PCB ............................................................................................. 5- 24

5.4.3.2 Removing the Inverter PCB .......................................................................................................... 5- 24

5.4.4 Scanner Motor ........................................................................................................................................ 5- 25

5.4.4.1 Before Removing the Scanner Motor .......................................................................................... 5- 25

5.4.4.2 Removing the Scanner Motor ....................................................................................................... 5- 25

5.4.5 Contact Sensor ....................................................................................................................................... 5- 25

5.4.5.1 Before Removing the Contact Image Sensor (CIS) .................................................................. 5- 25

5.4.5.2 Removing the Contact Image Sensor (CIS) ............................................................................... 5- 25

5.4.5.3 After Replacing the CIS ................................................................................................................. 5- 26

5.4.6 Original Cover Sensor ........................................................................................................................... 5- 26

5.4.6.1 Before Removing the Copyboard Cover Open/Closed Sensor (front/rear)........................... 5- 26

5.4.6.2 Removing the Copyboard Cover Open/Closed Sensor (front/rear)........................................ 5- 26

5.4.7 Contact Sensor HP Sensor................................................................................................................... 5- 27

5.4.7.1 Before Removing the Contact Sensor HP Sensor .................................................................... 5- 27

5.4.7.2 Removing the Contract Sensor Home Position Sensor ........................................................... 5- 27

5.4.8 Original Sensor ....................................................................................................................................... 5- 27

5.4.8.1 Before Removing the Original Size Sensor (AB/Inchconfiguration) ....................................... 5- 27

5.4.8.2 Removing the Original Size Sensor (AB/Inch-configuration)................................................... 5- 27

Table of Contents