Panasonic FP-D250 User Manual page 46

2) Developing
• The developer mixing unit contains developer which is a mixture of fine powder
(non-magnetic toner) and fine ferrite carrier.
• The developer is mixed by the transport screw and the mixing mill. The toner
becomes negatively charged ( – ) and the carrier becomes positively charged
( + ). The developer is magnetically attracted to the aluminum sleeve of the
magnetic roller, and the magnetic brush is formed.
• The magnetic roller sleeve rotates in a counterclockwise direction. The height
of magnetic brush is controlled by the gap between the doctor blade and the
sleeve surface.
• The drum, with an electrostatic latent image, is rotated clockwise and makes
contact with the magnetic brush.
• The negatively charged toner is attracted to the electrostatic latent image on
the drum.
• Charge (developer bias) is applied to the magnetic roller sleeve, which prevents
toner from moving to the non-image area of the drum. The distance between
the drum and the sleeve is controlled by the drum spacers.
FP-D250/D350 Series
Amount of developer Approx. 750 g
Initial toner density 6.0 %
Sleeve revolution 236.9 rpm
Drum revolution 67 rpm
Magnet roller diameter 30 mm
Drum Sleeve Distance 0.8 mm
Blade Sleeve Distance 0.67 mm ± 0.03 mm 0.63 mm ± 0.03 mm
Developing bias voltage –550 V reference
FP-D450
Approx. 750 g
5.1 %
465.4 rpm
95.5 rpm
30 mm
0.75 mm
–550 V reference
N3
S1
S3
S2
N1
N2
FP-D600
Approx. 750 g
5.1 %
542.9/465.4 rpm
111.4/95.5 rpm
30 mm
0.75 mm
0.63 mm ± 0.03 mm
–550 V reference
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