Canon ImageCLASS MF4690, Service Manual

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Chapter 5
5-1
5.1 Overview/Configuration
5.1.1 Overview
0016-1833
F-5-1
The laser scanner assembly is composed of the laser driver and the scanner motor etc., and controlled by the signal input from the DCNT board.
The laser driver emits laser diode according to the laser control signal and the video signal from the DCNT board.
The laser beam passes the collimator lens and the cylindrical lens, and reaches the four-surface mirror rotating at constant speed.
The laser beam reflected by the four-surface mirror passes through the condensing lens placed in front of the four-surface mirror and focuses on the photosensitive
drum.
When the four-surface mirror rotates at constant speed, the laser beam on the photosensitive drum scans the photosensitive drum at constant speed.
When the photosensitive drum rotates at constant speed and the laser beam scans the photosensitive drum at constant speed, the latent image is formed on the pho-
tosensitive drum.
MEMO:
E100: When the error related to the following laser exposure occurs, error code (E100) is lit.
BD fault
If /BDI signal cannot be detected in 0.1 sec after forced acceleration of the scanner motor or the specified value of /BDI signal cycle cannot be detected for
2 sec or more after the scanner motor reached the specified rotation, it should be judged as BD fault.
Scanner fault
If /BDI signal cannot be detected 1.5 sec after completing forced acceleration of the scanner motor, extend the detection time by 120 sec. If the specified
value of /BDI signal cycle cannot be detected during that time, it should be judged as scanner fault.
BD error
If /BDI signal cannot be detected at the specified cycle during /BDI signal output, it should be judged as BD error.
If the case of the following conditions, it should not be judged as BD error.
In the case that door open is detected in 0.2 sec after BD error was detected.
The laser scanner has the components unadjustable in the field. Never disassemble the laser scanner unit.
[1] Laser driver PCB [5] Scanner motor
[2] BD sensor [6] Four-surface mirror
[3] Photosensitive drum [7] Cylindrical lens
[4] Condensing lens
[1]
[4]
[5]
[6]
[7]
[2]
[3]