14 June, 2002
PRINTER
6-17
D
e
tailed
D
escr
iptions
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. The threshold value cannot be changed.
A hundred pages can be printed after detecting the near-end condition, then the
machine stops printing and toner end is detected.
When a new cartridge is installed, the machine clears the near-end condition if the
toner near-end sensor detects that there is sufficient toner.
No adjustment is required after the sensor is replaced.
Toner Supply
The toner in the toner cartridge is mixed by the agitators and mixing blade. The
toner near-end sensor is not used to control toner supply. When the machine is
turned on or the left cover is closed, the agitators 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 1.6 kVp-p 2 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.
