Ricoh FT6645 Manual page 28

23 April 1993
1.1.2 Image Density Control
Image density is controlled by the following sensors:
Toner density sensor (TD sensor)
Image density sensor (ID sensor)
Data from the TD sensor is used to keep the toner concentration in the
developer at a constant level. However, the image on the OPC drum varies
due to the variation of toner chargeability (influenced by the environment)
even if the toner concentration is constant. By the ID sensor compensation,
toner concentration is changed to keep the image density on the OPC drum
constant.
The following items are controlled to maintain a constant copy image density:
Toner supply clutch on time
Toner supply level data (V ) of the TD sensor
REF
2-3
PROCESS CONTROL