Oki OKIPAGE 12i Series, Service Handbook

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The image roller surface is charged to about –750 V by the contact charge of the charge roller.
When the 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. Likewise, the negative carriers flow into
the aluminum layer (ground).
The positive carriers moved to the CTL combine with the negative charges on the image drum
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 portion of the image
drum surface forms an electrostatic latent image on it. The irradiated portion of the image
drum surface is kept to about –100 V.
(V)
–750
–100
0
Light
from
LED
Image drum
surface potential
Charged part
Part
irradiated
by
LED
Charged
part