Ricoh FT4460, Service Manual, Page: 90 / 413

28 February 1989
5.9 TONER DENSITY CONTROL
[BLACK]
The image density sensor checks
once every 10 copy cycles (every
[COLOR]
the density of the sensor pattern image
5 copy cycles in color copy mode). The
CPU receives two voltage values directly from the sensor: the value for the
bare drum (Vsg) and the value for the sensor pattern (Vsp). These two values
are then compared to determine whether more toner should be added.
This model has two modes: the ID sensor supply mode and the fixed supply
mode. The ID sensor mode is used when the black development unit is in
use. The fixed supply mode is used when the color develop unit is in use. The
fixed supply mode can be selected when using the black development unit by
SP Mode #30.
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