Canon iR C6800 Series Service Manual page 663

Contents
9.1 Construction ....................................................................................................................................................... 9 1
9.1.1 Specifications, Control Mechanisms, and Functions .................................................................................. 9 1
9.1.2 Major Components ...................................................................................................................................... 9 2
9.1.3 Construction of the Control System ............................................................................................................ 9 5
9.2 Basic Sequence................................................................................................................................................... 9 6
9.2.1 Sequence of Operation at Power On ........................................................................................................... 9 6
9.2.2 Basic Sequence of Operation (printing) ...................................................................................................... 9 7
9.3 Various Control Mechanisms............................................................................................................................. 9 9
9.3.1 Controlling the Speed of the Fixing Roller ................................................................................................. 9 9
9.3.1.1 Controlling the Speed According to Paper Type.................................................................................. 9 9
9.3.1.2 Controlling the Speed for Large Volume Printing (down sequence)................................................... 9 9
9.3.1.3 Interval Rotation................................................................................................................................. 9 11
9.3.2 Controlling the Fixing Roller Temperature............................................................................................... 9 12
9.3.2.1 Overview ............................................................................................................................................ 9 12
9.3.2.2 At Power On....................................................................................................................................... 9 13
9.3.2.3 In Standby........................................................................................................................................... 9 14
9.3.2.4 When Producing Mono Color (Black) Single Sided Prints ............................................................... 9 15
9.3.2.5 When Producing Mono Color (Black) Double Sided Prints.............................................................. 9 15
9.3.2.6 When Producing Full Color Prints ..................................................................................................... 9 16
9.3.2.7 With Power Save Mode Enabled........................................................................................................ 9 17
9.3.2.8 Controlling the Overheating at the End of the Roller......................................................................... 9 17
9.3.3 External Heat Roller Drive Control........................................................................................................... 9 17
9.3.3.1 Overview ............................................................................................................................................ 9 17
9.4 Fixing Cleaning Web Mechanisms .................................................................................................................. 9 19
9.4.1 Overview ................................................................................................................................................... 9 19
9.4.2 Web Retaining Mechanism ....................................................................................................................... 9 20
9.5 Protective Functions ......................................................................................................................................... 9 22
9.5.1 Detecting Overheating Using Thermistors................................................................................................ 9 22
9.5.2 Cutting Off the Power Using Thermal Switches....................................................................................... 9 22
9.5.3 Errors ......................................................................................................................................................... 9 22
9.6 Parts Replacement Procedure........................................................................................................................... 9 24
9.6.1 Fixing Unit ................................................................................................................................................ 9 24
9.6.1.1 Removing the Fixing Assembly ......................................................................................................... 9 24
9.6.1.2 Points to Note When Mounting the Fixing Assembly........................................................................ 9 25
9.6.2 Fixing Roller.............................................................................................................................................. 9 25
9.6.2.1 Removing the Fixing Assembly ......................................................................................................... 9 25
9.6.2.2 Removing the Fixing Upper Heater ................................................................................................... 9 27
9.6.2.3 Removing the Fixing Roller ............................................................................................................... 9 28
9.6.2.4 Points to Note When Removing the Fixing Roller............................................................................. 9 29
9.6.3 Pressure Roller .......................................................................................................................................... 9 29
9.6.3.1 Removing the Fixing Assembly ......................................................................................................... 9 29
9.6.3.2 Removing the Fixing Lower Heater ................................................................................................... 9 31
9.6.3.3 Removing the Pressure Roller ............................................................................................................ 9 31
9.6.3.4 Points to Note When Mounting the Pressure Roller .......................................................................... 9 32
9.6.4 External Heat Roller .................................................................................................................................. 9 32
9.6.4.1 Removing the Fixing Assembly ......................................................................................................... 9 32
9.6.4.2 Removing the Outside Heating Roller Heater.................................................................................... 9 34
9.6.4.3 Removing the Outside Heating Roller ............................................................................................... 9 36
Contents