Canon Vizcam 1000, Service Manual

Page: 33 / 840

COPYRIGHT © 2001 CANON INC. CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
2-3
2. COPYING PROCESS
B. Static Latent Image
Formation Block
This block consists of three steps and
ultimately leaves negative charges in the areas of
the photosensitive drum representing the white
(light) areas of the original, while neutralizing the
charges in the areas representing the black (dark)
areas of the original.
Such an image created on the photosensitive
drum using differences in potential is not visible to
the human eye and is called a static latent image.
Figure 2-103
C. Pre-Exposure (step 1)
Figure 2-104
In preparation for primary charging, the light
from the pre-exposure lamp is directed to the
surface of the photosensitive drum to remove
residual charges, thereby preventing uneven copy
density.
Time (t)
0
-500
-1000
Light area
(exposed to laser)
Dark area
(white on original)
Pre-exposure
(step 1)
Primary charging
(step 2)
Image exposure
(step 3)
V
D
V
L
Surface potential (V)
Photosensitive
drum
-
-
-
-
Pre-exposure lamp
+
+
+
+