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Technology > Image Formation System > Controls > Developing/drum
Technology > Image Formation System > Controls > Developing/drum
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Drum heater control
The drum heater is attached below the photosensitive drum to keep stabilized charging and
exposure according to the environmental change in the machine.
This heater is controlled to keep constant internal temperature. Basically, when the
Environment Switch is ON, the heater is ON regardless of ON/OFF of the main power except
for during printing. (Excluding the case where the internal temperature is high).
It also controls the Cassette Heater in the same manner. (For details, refer to Cassette Heater
Control in Pickup Feed System.)
Photosensitive
drum
Drum heater
F-2-79
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Drum rotation speed control
This control is performed to keep a uniform drum rotation speed in order to increase accuracy
of the image position (color displacement).
Execution timing
1) The drum rotates, driven by the drum motors (M1 to M4).
2) There is an encoder on the drum shaft, of which rotation is monitored by the two sensors (Y:
UN31/32, M: UN33/34, C: UN35/36, Bk: UN37/38,).
3) This sensor counts the drum count based on a pulse, and feeds back the drum rotation
speed to the drum DC controller to perform speed control.
Drum motor
(M1~M4)
Photosensitive drum
DC controller (UN1)
Drum encoder sensor 1
(UN31 / 33 / 35 / 37)
Drum encoder sensor 2
(UN32 / 34 / 36 / 38)
F-2-80