Ricoh B089 - Page 99

DEVELOPMENT
SM 2-39 B089/B093
Detailed
Descriptions
There are four toner density control modes as follows.
Mode
Sensor control 1 (SP2-921, “0”): Normally use this setting only
Toner supply decision Compare Vt with a reference voltage (Vts or Vref)
Toner control process 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).
Toner supply amount Varies
Toner end detection Performed
Mode
Sensor control 2 (SP2-921, “1”): For designer’s use only; do
not use in the field
Toner supply decision Compare Vt with a reference voltage (Vts)
Toner control process This toner control process is the same as sensor control 1
mode. However, the reference voltage used is always Vts.
Toner supply amount Varies
Toner end detection Performed
Mode
Fixed control 1 (SP2-921, “2”): For designer’s use only; do not
use in the field
Toner supply decision Compare Vt with a reference voltage (Vts or Vref)
Toner control process This toner control process is the same as sensor control 1
mode.
Toner supply amount Fixed (SP2-925)
Toner end detection Performed
Mode
Fixed control 2 (SP2-921, “3”): Use temporarily if the TD
sensor needs to be replaced
Toner supply decision None
Toner control process Toner is supplied every printed page regardless of Vt.
Toner supply amount Fixed (SP2-925)
Toner end detection Not performed