Toner Density Control; Overview; Reference Voltage; Toner Density Sensor Initial Setting - Gestetner B130 Service Manual

6.16.4 TONER DENSITY CONTROL

Overview

Toner concentration in the developer is controlled using the following values:
• Vts:
TD sensor initial setting (1.25V). (Used as reference
voltage when Vref is not available.)
• Vref:
Toner supply reference voltage (calculated value;
periodically updated)
• Vt:
Actual output from TD sensor
• Vsg/Vsp:
Values from ID sensor, where Vsp is the voltage of a test
pattern (the "ID sensor pattern"), and Vsg is the voltage
of the bare drum
Toner is added to the development unit if Vt is higher than the reference voltage.

Reference Voltage

Vts is used as the reference if the PCU has just been installed (since Vref has not
yet been calculated) or if ID sensor correction has been disabled with SP2-927. In
all other cases, Vref is used as the reference.

Toner Density Sensor Initial Setting

The Vts for this machine is 1.25 V. During TD sensor initialization (after installation
of new PCU), the machine adjusts the sensor so that it reads out 1.25V.
SM
CÓPIA NÃO CONTROLADA
6-41
CÓPIA NÃO CONTROLADA
DEVELOPMENT
Toner Supply Clutch ON Time
Calculation
TD Sensor Output
(Vt)
Vref
Vref Update
ID Sensor Output
(Vsp/Vsg)
TD Sensor Initial
Setting (Vts)
B129 Series/B044 Series
B046D600.WMF