Canon iR5055, Service Manual

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Chapter 6
6-1
6.1 Construction
6.1.1 Overview
0015-4421
iR5065 / iR 5055 / iR5075 / iR5075N / iR5065N / iR5055N
The machine's laser exposure system consists of the laser unit that serves as the source of light and the laser scanning unit that uses a polygon mirror to control the
beam of laser light (for main scanning direction).
1) The video signal from the controller block is converted into a laser drive signal by the video PCB, and is sent to the laser drive PCB. The laser drive signal is
used to turn on the laser unit for generation of a laser beam.
2) The laser beam will assume a specific scanning direction upon hitting the polygon mirror rotating at a high speed.
3) The surface of the photosensitive drum is charged to a positive potential. When the laser beam hits specific areas of the drum surface, a static image occurs
as a result.
In addition, the laser beam is also used for blank exposure applied to non-imaging areas.
T-6-1
6.1.2 Major Components
0015-4422
iR5065 / iR 5055 / iR5075 / iR5075N / iR5065N / iR5055N
The machine's laser exposure system consists of the following major components:
The machine uses a small-diameter 12-facet polygon mirror and a wide-area lens to enable scanning at high speed, at low power consumption, and at low operating
noise. The laser unit is a double-beam unit.
F-6-1
T-6-2
Item Description
Laser intensity control [1] laser power auto control (APC control)
[2] optimum intensity control to suit drum surface potential
Laser scanning method scanning by semi-conductor laser
synchronization control main scanning direction: control by BD signal
sub scanning direction: controlled by laser write start signal
Laser scanner motor control [1] constant speed rotation control
[2] full/standby speed switchover
Item Description
Laser semi-conductor visible laser light (about 660 nm), double beam
Laser scanner motor DC motor, 2-speed control (at full speed, about 41338 rpm)
Polygon mirror 12 facets
BD mirror/BD PCB laser beam detection
laser driver PCB Laser activation control
Video PCB laser scanner motor rotation control
Polygon mirror
Laser unit
BD mirror
Laser mirror 2
Laser mirror 3
Laser mirror 4
Laser mirror 1
Photosensitive drum
BD PCB