Drum Unit; Outline Of The Drum Unit; Drum Receptacle Presence / Absence Detection - Canon imagerunner C5180 Service Manual

9.6 Drum Unit

9.6.1 Outline of the Drum Unit

9.6.1.1 Outline of the Drum Unit
The drum unit consists of the developing assembly, photosensitive drum, auxiliary brush, and charging
mechanism.
As many as 4 units are used (Y, M, C, Bk), and all of them have the same construction.
Developing
assembly
ATR sensor

9.6.1.2 Drum Receptacle Presence / Absence Detection

Drum unit presence / absence detection
Drum presence / absence is detected by measuring the current on the primary charging roller.
The current on the primary charging roller ( i ) is detected by the HV1 PCB, and voltage is calculated by I/V
conversion of the current value.
By rectifying this voltage using the HV1-SUB PCB and by A/D conversion using the DC controller PCB, the
detected voltage V is calculated.
The detected voltage V and the specified voltage v are compared to detect the presence / absence of the drum
unit.
- In the case the drum unit is present
Detected voltage V < specified voltage v
- In the case the drum unit is absent
Detected voltage V > specified voltage v
Primary charging
roller
Developing
cylinder
Developing Photosensitive
blade drum
F-9-22
Cleaning sheet
Downstream
auxiliary
brush
Upstream
auxiliary
brush
Chapter 9
9-29