Ricoh Aficio 220 Service Manual page 82

20 September 1999
There are four toner density control modes as follows.
Mode
Toner supply decision
Toner control process
Toner supply amount
Toner end detection
Mode
Toner supply decision
Toner control process
Toner supply amount
Toner end detection
Mode
Toner supply decision
Toner control process
Toner supply amount
Toner end detection
Mode
Toner supply decision
Toner control process
Toner supply amount
Toner end detection
Sensor control 1 (SP2-921, "0"): Normally use this setting only
Compare Vt with a reference voltage (Vts or Vref)
Toner is supplied to the development unit when Vt is higher
than the reference voltage (Vts or Vref). This mode keeps the
Vref value for use the next toner density control.
Vts is used for the first toner density control after a new PCU
has been installed, until it has been corrected with the ID
sensor output.
Vref is used after Vts has been corrected with the ID sensor
output voltage (corrected during the first toner density control
for a new PCU).
Varies
Performed
Sensor control 2 (SP2-921, "1"): For designer's use only; do
not use in the field
Compare Vt with a reference voltage (Vts)
This toner control process is the same as sensor control 1
mode. However, the reference voltage used is always Vts.
Varies
Performed
Fixed control 1 (SP2-921, "2"): For designer's use only; do not
use in the field
Compare Vt with a reference voltage (Vts or Vref)
This toner control process is the same as sensor control 1
mode.
Fixed (SP2-925)
Performed
Fixed control 2 (SP2-921, "3"): Use temporarily if the TD
sensor needs to be replaced
None
Toner is supplied every printed page regardless of Vt.
Fixed (SP2-925)
Not performed
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DEVELOPMENT