Canon imageRunner 2022, Service Manual

Page: 175 / 418

Chapter 5
5-1
5.1 Construction
5.1.1 Overview
0017-2643
iR2022i / iR2025 / iR2030 / iR2018 / iR2022 / iR2018i
The laser scanner unit consists of a laser driver, scanner motor, and others. It is controlled by the signals from the DC controller PCB.
The laser driver operates the laser diode to emit light in response to the laser control signals and video signals from the DC controller PCB.
Laser beams are emitted, through a collimator lens and cylindrical lens, to the hexahedral mirror rotating at a constant speed.
Laser beam reflected by the hexahedral mirror focus on the photoconductor drum via the imaging lens and loop-back mirrors installed before the hexahedral mirror.
When the hexahedral mirror rotates at a constant speed, the photoconductor drum is scanned with laser beams at a constant speed.
When the photoconductor drum rotates at a constant speed and the photoconductor is scanned with laser beams at a constant speed, a latent image is formed on the
photoconductor drum.
5.1.2 Specifications and Control Mechanism
0017-2646
iR2022i / iR2025 / iR2030 / iR2018 / iR2022 / iR2018i
T-5-1
5.1.3 Main Components
0017-2647
iR2022i / iR2025 / iR2030 / iR2018 / iR2022 / iR2018i
F-5-1
T-5-2
Laser beam
Number of laser beams 2 beams
Scanner Motor
Type of motor DC brushless motor
Rotation control Constant speed rotaion control
Polygon Mirror
Number of facets 6 facets (40-mm dia.)
Control Mechanism
Synchronous control Horizontal (main scan) synchronization
control
Light intensity control Automatic photocurrent control (APC)
Others Laser emission ON/OFF control
Laser scanner motor control
Laser shutter control
Name Function
[1] Photoconductive drum Receives laser beams to form a latent image.
[1]
[2] [3]
[4]
[5]
[6]
[7]