Ricoh FT4227 Manual page 260

12 February 1992
Vsg
Vsp
[Black Toner]
(1) Detect supply mode
In the detect supply mode toner will be supplied under the following
conditions:
Black toner ...........................Vsp/ Vsg x 100 ≥ 10
Color toner ...........................Vsp/ Vsg x 100 ≥ 25
(2) Fixed supply mode
A fixed amount of toner is supplied every copy cycle when the fixed
supply mode is selected (when the data of SP mode #30 is "1").
On this copier, this mode can be selected only for black toner.
The CPU monitors Vsp and Vsg once every 10 copy cycles even in the
fixed supply mode.
To avoid over toning, the CPU stops toner supply when Vsp becomes
1/10 Vsg or less.
Vsg
100% (4.0 V)
Low Density
Vsp
10% (0.4 V)
High Density
2-5
PROCESS CONTROL
100% (4.0 V)
Low Density
25% (1.0 V)
[Color Toner]
High Density