OKIDATA OF2200, Руководство по обслуживанию

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1.5.05 Exposing
The image drum has four layers.
· Carrier Transfer Layer (CTL)
· Carrier Generation Layer (CGL)
· Underlayer (UL)
· Aluminum Base
The CTL and CGL make up the organic photo conductor layer (OPC), which is about 20 micrometers (m
m) thick.
When light from the LED head irradiates the image drum surface, the light energy generates positive and
negative carriers in the CGL. The positive carriers are moved to the CTL by an electrical field acting on the
image drum. The negative carriers flow into the aluminum layer (ground).
The positive carriers moved to the CTL combine with the negative charges on the image surface
(accumulated by the contact charge of the charge roller), lowering the potential on the image drum
surface. The resultant drop in the potential of the irradiated part of the image drum surface forms an
electrostatic latent image on it. The surface potential on this irradiated part of the image drum is
approximately -100 vdc.