ContentsContents5.1 Construction ....................................................................................................................................................... 5-15.1.1 Specifications, Control Mechanisms, and Functions .................................................................................. 5-15.1.2 Major Components ...................................................................................................................................... 5-25.1.3 Construction of the Control System ............................................................................................................ 5-45.1.4 Reader Controller PCB................................................................................................................................ 5-55.2 Basic Sequence................................................................................................................................................... 5-75.2.1 Basic Sequence of Operation at Power-On ................................................................................................. 5-75.2.2 Basic Sequence of Operation in Response to a Press on the Start ............................................................. 5-75.2.3 Basic Sequence of Operation in Response to a Press on the Start ............................................................. 5-85.3 Various Control ................................................................................................................................................ 5-105.3.1 Controlling the Scanner Drive System ...................................................................................................... 5-105.3.1.1 Outline ................................................................................................................................................ 5-105.3.1.2 Controlling the Reader Motor ............................................................................................................ 5-105.3.2 Contact Image Sensor (CIS)...................................................................................................................... 5-125.3.2.1 Outline ................................................................................................................................................ 5-125.3.2.2 Analog Control Inside the Contact Image Sensor .............................................................................. 5-135.3.3 Enlargement/Reduction ............................................................................................................................. 5-145.3.3.1 Changing the Magnification in Main Scanning Direction ................................................................. 5-145.3.3.2 Varying the Magnification in Sub Scanning Direction ...................................................................... 5-145.3.4 Detecting the Size of Originals ................................................................................................................. 5-165.3.4.1 Outline ................................................................................................................................................ 5-165.3.4.2 Outline of Size Identification ............................................................................................................. 5-175.3.5 Dirt Sensor Control ................................................................................................................................... 5-195.3.5.1 Outline ................................................................................................................................................ 5-195.3.6 Image Processing....................................................................................................................................... 5-225.3.6.1 Outline ................................................................................................................................................ 5-225.3.6.2 CCD Drive.......................................................................................................................................... 5-235.3.6.3 Gain Correction and Offset Correction of the CCD Output............................................................... 5-235.3.6.4 A/D Conversion of the CCD Output .................................................................................................. 5-245.3.6.5 Shading Correction (outline) .............................................................................................................. 5-245.3.6.6 Shading Adjustment ........................................................................................................................... 5-245.3.6.7 Shading Correction............................................................................................................................. 5-245.4 Parts Replacement Procedure........................................................................................................................... 5-265.4.1 Copyboard glass ........................................................................................................................................ 5-265.4.1.1 Removing the Copyboard Glass......................................................................................................... 5-265.4.1.2 Removing the ADF Reading Glass .................................................................................................... 5-275.4.2 Reader Controller PCB.............................................................................................................................. 5-285.4.2.1 Before Replacing the Reader Controller PCB.................................................................................... 5-285.4.2.2 Removing the Reader Rear Cover...................................................................................................... 5-285.4.2.3 Removing the rear cover of the machine............................................................................................ 5-295.4.2.4 Removing the flexible cable cover ..................................................................................................... 5-295.4.2.5 Removing the Copyboard Glass......................................................................................................... 5-305.4.2.6 Removing the Reader Controller PCB ............................................................................................... 5-315.4.2.7 After Replacing the Reader Controller PCB or After Initializing the RAM...................................... 5-35
