Ricoh A085, Manual

Page: 308 / 617

6.5.5 Bias Voltage Selection by SP Mode
The development bias for original image can be selected from among four
levels by SP mode #37 for black and SP mode #79 for color as shown in the
above table.
The selected development bias voltage does not affect the toner density
control because the development bias for the ID sensor patterns have a
different table.
Since the V
R
pattern and V
L
pattern detections are performed in black copy
cycles, the setting of SP37 is applied to the development bias voltage for the
V
R
and V
L
patterns. Therefore, if you change the black development bias
after the initial V
L
detection, the difference will be gradually neutralized by the
exposure lamp voltage when the subsequent V
L
detections are performed.
(Ex. If you decrease the negative development bias voltage by +40V to get a
darker image, the V
L
pattern will also become darker and the exposure lamp
voltage increases by 1V. After several V
L
pattern detections, the image
darkened by the development bias voltage will return to the initial image
density as a result of V
L
pattern detections.) The development bias voltage
adjustment should be done with the exposure lamp voltage adjustment
(SP48) only when the drum initial setting (SP66) is performed.
The color development bias voltage can be adjusted any time.
Data Density
Develpment Bias
Correction Voltage
0 Normal
±
0V
1 Darkest +40V
2 Darker +20V
3 Lighter –20V
4 Lightest –40V
SP37: Black Bias
SP79: Color Bias
Det
a
il
ed
Descriptions
12 February 1992 DEVELOPMENT
2-53