Toner Density Sensor Initial Setting; Toner Concentration Measurement; Vsp/Vsg Detection; Toner Supply Reference Voltage (Vref) Determination - Ricoh K-C1 Service Manual

DEVELOPMENT

Toner Density Sensor Initial Setting

The TD sensor initial setting (SP2-214: Developer Initialize) procedure must be
done after replacing the developer. During TD sensor initial setting, the TD sensor
is set so that the TD sensor output is the value of SP2-926 (default: 2.4 V). This
value will be used as the standard reference voltage (Vts) of the TD sensor.

Toner Concentration Measurement

The toner concentration in the developer is detected once every copy cycle. The
sensor output voltage (Vt) during the detection cycle is compared with the standard
reference voltage (Vts) or the toner supply reference voltage (Vref).

Vsp/Vsg Detection

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.
Vsp/Vsg is not detected every page or job; it is detected at the following times to
decide Vref.
• During warm-up at power on
• If the machine starts warming up after a certain time (default: 90 minutes)
has passed since entering night mode or low power mode
The 90-minute interval can be changed using SP2-995.

Toner Supply Reference Voltage (Vref) Determination

The toner supply reference voltage (Vref) is used for toner supply determination
(see below). Vref is determined using the following data:
• ID sensor output (Vsp/Vsg)
• (Vts or the current Vref) - Vt

Toner Supply Determination

The reference voltage (Vts or Vref) is the threshold voltage for determining whether
or not to supply toner. If Vt becomes greater than the reference voltage, the
machine supplies additional toner.
This can be checked using SP2-220.
6-46
20 February, 2001