Canon 1000 Service Manual page 134

3. OPERATION AND TIMING
The DC component of the grid and the developing biases is determined based on the Vg-Vd and Vg-V1
characteristics obtained through drum surface potential measurement and the target contrast potential
computed by PASCAL as follows:
The developing bias DC (Vdc) curve is
obtained from the Vd characteristic curve.
The potential between Vdc and VL in Figure
3-510 is the contrast potential.
The point identical to the target contrast
potential is detected, and the point is used to
obtain the target value of the grid and developing
biases; in the case of Figure 3-511, V1 and V2 are
target values.
The measurement data for the surface potential may be checked in service mode.
Operation/inspection mode (FUNCTION)
Item
V00-300V
V00-700V
VFF-300V
VFF-700V
3-90
COPYRIGHT © 2001 CANON INC.
Photosensitive drum potential measurement (EPC)
Description
Surface potential at 00 activation
Surface potential at 00 activation
Surface potential at full activation
Surface activation at full activation
Table 3-501
CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
Potential
(negative)
Figure 3-510
Potential
(negative)
V1
Grid bias
Figure 3-511
Reference
280 to 380
480 to 620
35 to 145
40 to 190
Specific value subtracted
Vd
Vdc
Contrast potential
VL
Vdc
VL
V2