Image Formation System - Canon NP6085 Service Manual

3. OPERATIONS AND TIMING
III. IMAGE FORMATION
SYSTEM
A. Controlling the Drum Surface
Potential
1. Outline
Changes in the latent images can significantly
affect the quality of copy images. Such changes in
the latent image in turn are usually caused by the
following:
1 changes in the drum sensitivity.
2 changes in the charging volume of the primary
charging assembly.
3 changes in the degree of exposure.
The above are brought about by deterioration
or soiling of parts or changes in the site environ-
ment (temperature/humidity).
The NP6085 is equipped with a drum surface
potential control mechanism that serves to ensure
reproduction of stable latent images in the pres-
ence of the above factors.
The NP6085 varies the light area target poten-
tial (V ), dark area target potential (V
L1
trol coefficient according to the drum sensitivity so
as to produce stable images.
Caution:
Use the light area potential, dark area
potential, and control coefficient recorded
on the sheet that comes with the drum;
enter the settings only when replacing the
drum.
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COPYRIGHT © 1996 CANON INC.
), and con-
D
CANON NP6085 REV.0 JULY 1996 PRINTED IN JAPAN (IMPRIME AU JAPON)