Canon imageRUNNER ADVANCE C255 Series, Service Manual, Page: 66 / 987

Parts name Role
Developing Assembly The toner fed from the Hopper Unit is developed on the Photosensitive Drum.
Developing Cylinder The toner and carrier inside the Developer Container are coated on the surface, and the toner
is developed on the Photosensitive Drum.
Developer Feed Screw A Toner and carrier in the Developer Container are supplied to the Developing Cylinder.
Developer Feed Screw B Toner and carrier in the Developer Container are stirred and supplied to the Developer Feed
Screw A.
Code Parts name Role
M03 Developing Motor To rotate the Y/M/C/Bk Developing Cylinder and the Developer Feed Screw.
UN34 to UN37 ATR Sensor (Y/M/C/Bk) To detect the ratio of developer (toner + carrier) in the Developing Assembly.
■ Developing Bias Control
A toner image is formed on the Photosensitive Drum by attaching toner to the Developing Cylinder.
Control description
The developing bias (AC, DC negative), which has been generated on the Developing High-voltage PCB (UN06), is applied to
the Developing Cylinder.
• Developing DC bias: The bias to generate potential difference with the Photosensitive Drum. The bias value is determined
based on the Environment Sensor (UN33).
• Developing AC bias: The bias to improve image quality.
Developing Cylinder
DC Controller PCB (UN04)
Developing High-voltage PCB (UN06)
■ Drum Overview
Cleaning
Screw
Photosensitive Drum
Primary Charging Roller
Cleaning
Blade
2. Technology
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