Ricoh B245-62 Service Training page 70

Vsp/Vsg Detection and Vref Determination
The ID sensor detects the following voltages.
» Vsg: The ID sensor output when checking the drum surface.
» Vsp: The ID sensor output when checking the ID sensor
pattern.
In this way, the reflectivity of both the drum surface and the
pattern on the drum are checked, compensating for any
variations in the reflectivity of the pattern on the drum or the
reflectivity of the drum surface.
The ID sensor pattern is made on the drum by the charge
roller and laser diode.
Vref (toner supply reference voltage) is Vsp/Vsg.
Vsp/Vsg is not detected every page or job. It is detected
during warm-up at power on.
Slide 70
While the machine is recovering from an energy saver mode, or while the
machine starts, the controller ignores the ID-sensor signals if the fusing
temperature is at or higher than the value specified by SP 2994. The default is
30°C.
Toner Density Control 3
70
B245-62 / PD-C4