Sharp AR-BC260 Service Manual page 55

d. Developing section (composed of four units of YMCK)
operations
Electrostatic latent images generated on the OPC drum by the
LED (writing) units are converted into visible images by toner.
OPC drum
CTL
CGL
Aluminum
layer
Toner in the developing unit is agitated by the mixing roller.
By mixing operation, toner is negatively charged due to mechani-
cal friction.
The developing bias voltage (negative) is applied to the develop-
ing roller.
The diflerence for the voltage potential between the toner and DV
roller surface attracts the toner to the DV roller.
In the areas of the OPC drum, when the charge was detected, the
voltage potential difference is greater than the DV roller. Therefore
the toner is attracted from the DV roller to the drum.
In the unexposed areas of the drum, the potential on the DV roller
created by the bias voltage and therefore the toner to not attracted
to those areas of the drum.
Negatively charged toner is attracted and attached to the exposed
area on the OPC drum surface where the negative potential was
reduced by LED exposure.
On the other hand, in the areas on the OPC drum where exposure
was not made, the positive potential is higher than the developing
bias voltage, repelling toner.
AR-BC260 DESCRIPTIONS OF EACH SECTION 7 - 18
<1> Remaining toner quantity detection
Rotation of the detection lever connected to the mixing roller is
sensed by the sensor (TES) to detect the remaining toner
quantity.
<2> Waste toner collection
Waste toner collected by the drum cleaning blade is trans-
ported to the waste toner box of the toner cartridge by the
toner transport spring in the drum unit.
Drive
Own weight
Drive
Own weight
OPC drum