Canon iR1600 Service Manual page 11

CHAPTER 3 IMAGE READING/PROCESSING SYSTEM
1 Outline of Operation ........................... 3-1
1.1 Outline ....................................... 3-1
2 Reader Drive System .......................... 3-2
2.1 Outline ....................................... 3-2
2.2 Controlling the Reader Motor .... 3-3
2.2.1 Moving the Carriage in
Reverse After an
Image Scan .......................... 3-3
3 Detecting the Size of Originals ........... 3-4
3.1 Outline ....................................... 3-4
3.2 Detection by the
Original Size Sensors ................. 3-4
3.3 Detecting the Size of
Originals ..................................... 3-6
3.4 Detection by the ADF ................ 3-7
4 Image Processing ................................ 3-8
4.1 Outline ....................................... 3-8
4.2 Contact Sensor ........................... 3-9
4.2.1 Outline of the Contact
Sensor .................................. 3-9
4.2.2 Construction of the Contact
Sensor (CS) ........................ 3-10
4.3 A/D Conversion ....................... 3-11
4.4 Shading Correction .................. 3-11
4.4.1 Black Shading
Correction .......................... 3-12
4.4.2 White Shading
Correction .......................... 3-12
4.5 Re-Ordering ............................. 3-12
4.6 ABC
(auto background control) ........ 3-13
4.7 LED Intensity Adjustment ....... 3-14
4.8 Enlargement/Reduction ............ 3-14
4.8.1 Enlargement/Reduction in Main
Scanning Direction ............ 3-14
4.8.2 Changing the Reproduction
Ratio in Sub Scanning
Direction ............................ 3-16
COPYRIGHT © 2002 CANON INC. 2001 2001 2001 2001 CANON iR1600/iR2000 REV.1 JAN. 2002
4.9 Edge Emphasis ......................... 3-17
4.10 Editing ...................................... 3-17
4.11 Density Conversion (LUT, i.e.,
look-up table processing) ......... 3-17
4.11.1 Density Adjustment
(F-value conversion) .......... 3-17
4.11.2 Density Correction
(g correction) ..................... 3-17
4.12 Binary Processing .................... 3-18
4.12.1 Error Diffusion .................. 3-18
4.13 Image Memory Control ........... 3-18
4.13.1 Compression/Expansion,
Rotation, and Enlargement/
Reduction ........................... 3-18
4.13.2 SDRAM ............................. 3-18
4.14 Output Image Processing ......... 3-19
4.14.1 Smoothing .......................... 3-19
5 Disassembly and Assembly .............. 3-20
5.1 Copyboard Glass ...................... 3-21
5.1.1 Removing the
Copyboard Glass ................ 3-21
5.1.2 After Replacing the
Copyboard Glass ................ 3-23
5.2 CS Unit .................................... 3-23
5.2.1 Removing the CS Unit ....... 3-23
5.2.2 Points to Note When
Mounting the CS Unit ....... 3-26
5.2.3 After Replacing the
CS Unit .............................. 3-28
5.2.4 Points to Note When
Handling the CS Unit ........ 3-29
5.3 Reader Motor ........................... 3-30
5.3.1 Removing the Reader
Motor ................................. 3-30
5.3.2 Points to Note When Mounting
the Reader Motor ............... 3-31
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