Ricoh FT4460, Service Manual, Page: 101 / 413

21 April 1989
5.19 ID SENSOR BIAS COMPENSATION
In order to ensure consistent operation of the ID sensor system, the bias for
the development of the sensor pattern must be able to change (or be
changed) to accommodate the following factors/conditions. (Numbers refer to
the charts above)
5.19.1 Standard Bias
I.D. Sensor Bias(Black)
0 ( N )
- 2 6 0 ( V )
1(L) - 2 2 0
S P M o d e N o . 3 3
2(H)
- 2 8 0
3 ( H H )
- 3 0 0
I n i t i a l D e v e l o p e r
Conditioning: –340V
I.D. Sensor Bias(Color)
0 ( N )
- 2 4 0 ( V )
- 3 2 0 ( V )
S P M o d e N o . 7 5
1(L) - 2 0 0 - 2 8 0
2 ( H )
- 2 6 0 - 3 4 0
3 ( H H ) - 2 8 0 - 3 6 0
Initial Developer Conditioning: Red = –280V
Blue/Green = -320V
1-1 and 1-2: ID sensor bias can be manually changed to accommodate cus-
tomer copy quality preferences by changing the settings of SP Mode #33 for
black developer and SP Mode #75 for color developer.
During initial conditioning, only SP Mode #33 (black) and SP Mode #75
(color) can change the ID sensor bias.
5.19.2 Vp Correction
OPC Counter
1000-1999
2000-2999 Mode Then
0-999 Copies
Copies
Copies
3000 Copies
Black
+ 0V + 20V
+ 40V + 80V
Color
+ 0V + 0V + 20V + 20V
Sensitivity on a new OPC drum’s surface will change with the first 3000
copies, so Vp is corrected as shown above.
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