Ricoh FT6645 Manual page 81

DEVELOPMENT
Fuzzy Control 2
The image on the OPC drum changes due to variations in toner
chargeability (influenced by the environment) even if toner
concentration is constant.
The ID sensor directly checks the image on the OPC drum and shifts
the V data under fuzzy control to keep the image on the OPC drum
REF
constant.
NOTE: The toner supply amount is changed at every copy cycle.
The target toner density sensor output is updated under the
following conditions:
1. During toner density sensor initial setting
2. During process control data initial setting
3. After the copy job is completed in case that 10 or more copies
have been made since the last update.
(Refer to section 2.1.4 "Image Density Control" for details.)
2) Detect Mode
In this mode, only the TD sensor is used to control the toner
concentration (V
control 1.
In ID sensor abnormal condition or Drum Potential sensor abnormal
condition, the machine automatically enter this mode.
3) Fixed Mode
In this mode, a fixed amount of toner is supplied every copy cycle as
determined (4%, 7%, 11%, 14%) by SP mode (
PAGE 7). There is no overtoning detection mechanism.
In TD sensor abnormal condition, the machine automatically enters this
mode.
data is fixed). The machine performs only fuzzy
REF
1
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23 April 1993
Adjustment mode: