Canon MF720 Series, Service Manual, Page: 37 / 327

Laser Control System
Overview
The Laser Scanner system is to form a static latent image on the photosensitive drum based on the video signal sent from the
Main Controller.
The Laser Scanner Unit is composed of the laser driver, the Scanner Motor Unit and other components, which are controlled
based on signals input by the DC Controller.
The figure below shows the Laser Scanner Unit schematically.
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㻸㼍㼟㼑㼞㻌㻰㼞㼕㼢㼑㼞
㻿㼏㼍㼚㼚㼕㼚㼓㻌㻹㼕㼞㼞㼛㼞
㻿㼏㼍㼚㼚㼕㼚㼓㻌㻹㼛㼠㼛㼞
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㻼㼔㼛㼠㼛㼟㼑㼚㼟㼕㼠㼕㼢㼑㻌㻰㼞㼡㼙
㻔㻯㻕
㻼㼔㼛㼠㼛㼟㼑㼚㼟㼕㼠㼕㼢㼑㻌㻰㼞㼡㼙
㻔㻹㻕
㻼㼔㼛㼠㼛㼟㼑㼚㼟㼕㼠㼕㼢㼑㻌㻰㼞㼡㼙
㻔㼅㻕
㻰㻯㻌㻯㼛㼚㼠㼞㼛㼘㼘㼑㼞
㻹㼍㼕㼚㻌㻯㼛㼚㼠㼞㼛㼘㼘㼑㼞
Controls
■ Failure detection
1. Scanner Motor failures
• The rotation does not reach the pre-defined value after a certain time elapsed from the Scanner Motor actuated.
• The rotation failed to meet the tolerable range consecutively within a certain time during the Scanner Motor in drive.
Error Code: E110-0000
2. BD failures
• When out-of-range BD cycle is detected during printing.
2. Technical Explanation
29