Ricoh G031 Service Manual page 58

TONER CARTRIDGE
Toner Near-End Sensor
The toner near-end sensor monitors the toner concentration by checking the
magnetic field strength.
When the reading goes down to a threshold value, the machine enters the near-
end condition. There is no toner end condition (the user replaces the cartridge
when the print quality has become unacceptable). The threshold value cannot be
changed.
No adjustment is required after the sensor is replaced.
Toner Supply
The toner in the toner cartridge is mixed by the agitator(s) and mixing blade. The
toner near-end sensor is not used to control toner supply. When the machine is
turned on or the front cover is closed, the agitator(s) and the mixing blade rotate to
mix the toner for a brief period.
Development Bias
The high voltage supply unit gives the development roller a charge of –400 V dc
and an ac component of 1.8 kVp-p 1.8 kHz ac is also used. To prevent toner from
transferring to non-image areas on the drum, the development bias is different for
image areas and non-image areas.
G031/G032 2-14 SM