Contents3.5.2.1 Preparation for Removing the SDRAM .................................................................................................................................. 3- 103.5.2.2 Removing the SDRAM........................................................................................................................................................... 3- 11Chapter 4 Original Exposure System4.1 Construction ...............................................................................................................................................4- 14.1.1 Specifications, Control Methods, and Functions (iR2030i/iR2030/iR2025i/iR2025/iR2022i/iR2022N/iR2022) ....... 4- 14.1.2 Major Components (iR2030i/iR2030/iR2025i/iR2025/iR2022i/iR2022N/iR2022) .................................................... 4- 14.1.3 Control System Configuration (iR2030i/iR2030/iR2025i/iR2025/iR2022i/iR2022N/iR2022) ................................... 4- 24.1.4 Reader Controller PCB (iR2030i/iR2030/iR2025i/iR2025/iR2022i/iR2022N/iR2022).............................................. 4- 34.2 Basic Sequence..........................................................................................................................................4- 44.2.1 Basic Sequence at Power-on .................................................................................................................................. 4- 44.2.2 Basic Sequence after Depression of Start Key (Book mode, One Sheet of original) .............................................. 4- 54.2.3 Basic Sequence after Depression of Start Key (ADF Mode, One Sheet of Original) .............................................. 4- 54.3 Various Control ...........................................................................................................................................4- 64.3.1 Controlling the Scanner Drive System..................................................................................................................... 4- 64.3.1.1 Outline...................................................................................................................................................................................... 4- 64.3.1.2 Reader Motor Control .............................................................................................................................................................. 4- 64.3.2 Contact Image Sensor (CIS) ................................................................................................................................... 4- 74.3.2.1 Outline...................................................................................................................................................................................... 4- 74.3.2.2 Analog Control Performed by the CIS (iR2030i/iR2030/iR2025i/iR2025/iR2022i/iR2022K/iR2018i) ....................................... 4- 84.3.3 Enlargement/Reduction ........................................................................................................................................... 4- 94.3.3.1 Magnification Change in Vertical Scan Direction ..................................................................................................................... 4- 94.3.3.2 Magnification Change in Horizontal Scan Direction................................................................................................................. 4- 94.3.4 Detecting the Size of Originals ................................................................................................................................ 4- 94.3.4.1 Outline...................................................................................................................................................................................... 4- 94.3.4.2 Outline of Original Size Detection ............................................................................................................................................ 4- 94.3.5 Dirt Sensor Control ................................................................................................................................................ 4- 114.3.5.1 Outline.................................................................................................................................................................................... 4- 114.3.6 Image Processing.................................................................................................................................................. 4- 134.3.6.1 Outline.................................................................................................................................................................................... 4- 134.3.6.2 CMOS Sensor Drive .............................................................................................................................................................. 4- 144.3.6.3 CMOS Sensor Output Gain Correction and Offset Correction............................................................................................... 4- 144.3.6.4 CMOS Sensor Output A/D Conversion.................................................................................................................................. 4- 144.3.6.5 Shading Correction (Outline) ................................................................................................................................................ 4- 144.3.6.6 Shading Adjustment............................................................................................................................................................... 4- 154.3.6.7 Shading Correction ................................................................................................................................................................ 4- 154.4 Parts Replacement Procedure .................................................................................................................4- 164.4.1 Copyboard glass.................................................................................................................................................... 4- 164.4.1.1 Removing the Copyboard glass............................................................................................................................................. 4- 164.4.1.2 Procedure after Replacing the Copyboard Glass (Model equipped with ADF) ...................................................................... 4- 164.4.1.3 Removing the ADF Reading Glass ........................................................................................................................................ 4- 164.4.2 Reader Controller PCB.......................................................................................................................................... 4- 164.4.2.1 Removing the Reader Controller PCB ................................................................................................................................... 4- 164.4.3 Scanner Motor ....................................................................................................................................................... 4- 174.4.3.1 Removing the Scanner Motor ................................................................................................................................................ 4- 174.4.4 Contact sensor ...................................................................................................................................................... 4- 184.4.4.1 Removing the Contact Image Sensor (CIS)........................................................................................................................... 4- 184.4.4.2 Procedure after Replacing the CIS(Touch panel type) .......................................................................................................... 4- 184.4.5 Copyboard Cover Open/Close Sensor .................................................................................................................. 4- 184.4.5.1 Removing the Copyboard Cover Open/Close Sensor (Front/Rear)....................................................................................... 4- 184.4.6 Contact Sensor HP Sensor ................................................................................................................................... 4- 184.4.6.1 Removing the Contact Sensor HP Sensor............................................................................................................................. 4- 184.4.7 Original Size Sensor.............................................................................................................................................. 4- 194.4.7.1 Removing the Original Sensor (Vertical Scan Direction) ....................................................................................................... 4- 194.4.7.2 Removing the Original Sensor (Horizontal Scan Direction) ................................................................................................... 4- 194.4.8 Reader Heater (option).......................................................................................................................................... 4- 204.4.8.1 Removing the Reader Heater (Right) .................................................................................................................................... 4- 204.4.8.2 Removing the Reader Heater (Left)....................................................................................................................................... 4- 20