Canon ImageRunner iR8500 Series Service Manual page 321

Contents
7.1 Construction ...................................................................................................................................................................7-1
7.1.1 Outline of the Laser Exposure System......................................................................................................................................... 7-1
7.1.2 Outline of the Laser Exposure System......................................................................................................................................... 7-1
7.2 Basic Sequence ..............................................................................................................................................................7-3
7.2.1 Basic Sequence of Operations (laser exposure system)............................................................................................................... 7-3
7.2.2 Basic Sequence ............................................................................................................................................................................ 7-3
7.3 Various Controls ............................................................................................................................................................7-4
7.3.1 Controlling the Laser Activation Timing..................................................................................................................................... 7-4
7.3.1.1 Flow of the BD Signal.....................................................................................................................................................................................7-4
7.3.2 Controlling the Intensity of Laser Light ...................................................................................................................................... 7-4
7.3.2.1 Outline.............................................................................................................................................................................................................7-4
7.3.2.2 Controlling Laser Activation...........................................................................................................................................................................7-5
7.3.2.3 Controlling the Laser Intensity........................................................................................................................................................................7-6
7.3.3 Controlling the Laser Scanner Motor .......................................................................................................................................... 7-7
7.3.3.1 Outline.............................................................................................................................................................................................................7-7
7.4 Parts Replacement Procedure.........................................................................................................................................7-9
7.4.1 Laser Scanner Unit....................................................................................................................................................................... 7-9
7.4.1.1 Removing the Laser Unit ................................................................................................................................................................................7-9
7.4.1.2 Removing the Laser Unit ................................................................................................................................................................................7-9
7.4.1.3 Removing the Laser Unit ................................................................................................................................................................................7-9
7.4.1.4 Removing the Laser Unit ..............................................................................................................................................................................7-10
7.4.1.5 Points to Note When Replacing the Laser Unit ............................................................................................................................................7-11
7.4.1.6 Points to Note When Replacing the Laser Unit ............................................................................................................................................7-11
7.4.2 BD Unit ...................................................................................................................................................................................... 7-11
7.4.2.1 Removing the BD Unit..................................................................................................................................................................................7-11
7.4.2.2 Removing the BD Unit..................................................................................................................................................................................7-11
Contents