1 May 1993TONER DENSITY DETECTION AND TONER SUPPLY
6.4ID SENSOR FUNCTION IN FIXED SUPPLY MODE
6.4.1 Black Development Unit
In fixed supply mode, toner is supplied every copy cycle according to the
fixed toner supply ratio data (SP mode), the paper size data and the color
data. However, the toner supply clutch is de-energized to prevent over-toning
when Vsp is lower than 1/8 Vsg.
Vsg 4VLow Density
Detailed
Descriptions
1/8 Vsg
Vsp
High Density
[BLACK]
6.4.2 Color Development Unit
When a color development unit is installed, the CPU automatically selects the
fixed toner supply mode. The amount of toner supplied depends on the fixed
toner supply ratio (SP70), the paper size data and the kind of color data.
The CPU calculates the threshold level for toner supply when the color
developer initial setting (SP10) procedure is completed. This level is
determined by calculating the average of Vsp/Vsg x 100(%).
Since the fixed supply mode is selected when in color toner mode, it is
necessary to inhibit toner supply if the toner density becomes high to prevent
over-toning. The CPU checks Vsp once every 5 copy cycles. If Vsp becomes
lower than the threshold level, the CPU stops supplying toner. Toner supply
resumes when Vsp rises above the threshold level again.
Vsg 4V
Low Density
Threshold Level
Vsp
High Density
[COLOR]
The threshold level (a percentage) for each color can be monitored in SP80
(Red), 81 (Green) and 82 (Blue).
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ACEC
RICOH
