Canon iR2020 Series Service Manual page 93

Contents
3.1 Construction ....................................................................................................................................................... 3-1
3.1.1 Construction and Mechanisms .................................................................................................................... 3-1
3.2 Construction of the Electrical Circuitry ............................................................................................................. 3-1
3.2.1 Image Processor PCB .................................................................................................................................. 3-1
3.3 Image Processing................................................................................................................................................ 3-2
3.3.1 Overview of the Image Flow....................................................................................................................... 3-2
3.3.2 Construction of the Image Processing Module ........................................................................................... 3-3
3.3.3 Reader Unit Input Image Processing........................................................................................................... 3-3
3.3.4 Compressio/ Extesion/ Editing Block ........................................................................................................ 3-4
3.3.5 Compressio/ Extesion/ Editing Block ........................................................................................................ 3-4
3.3.6 Printer unit Output Image Processing ......................................................................................................... 3-5
3.4 Flow of Image Data ............................................................................................................................................ 3-5
3.4.1 Flow of Image Data According to Copy Functions .................................................................................... 3-5
3.4.2 Flow of Image Data for the SEND Function............................................................................................... 3-6
3.4.3 Flow of Image Data for the Fax Transmission............................................................................................ 3-6
3.4.4 Flow of Image Data for the Fax Reception Function .................................................................................. 3-7
3.4.5 Flow of Image Data for the PDL Function.................................................................................................. 3-7
3.5 Parts Replacement Procedure............................................................................................................................. 3-9
3.5.1 Main Controller PCB................................................................................................................................... 3-9
3.5.1.1 Removing the Rear Cover .................................................................................................................... 3-9
3.5.1.2 Removing the Left Cover (Rear).......................................................................................................... 3-9
3.5.1.3 Removing the RAM Cover................................................................................................................... 3-9
3.5.1.4 Removing the SDRAM ........................................................................................................................ 3-9
3.5.1.5 Removing the LAN Cover.................................................................................................................... 3-9
3.5.1.6 Removing the IP Cover ........................................................................................................................ 3-9
3.5.1.7 Removing the IP Cover ...................................................................................................................... 3-10
3.5.1.8 Removing the image processor PCB.................................................................................................. 3-11
3.5.1.9 Procedure after Replacing the Image Processor PCB ....................................................................... 3-11
3.5.2 SDRAM..................................................................................................................................................... 3-11
3.5.2.1 Removing the Rear Cover .................................................................................................................. 3-11
3.5.2.2 Removing the RAM Cover................................................................................................................. 3-11
3.5.2.3 Removing the SDRAM ...................................................................................................................... 3-12
Contents