Developer Unit - Panasonic FP-D250 User Manual

3. Developer unit

1) Construction of the developer unit
• The developer unit consists of the magnet roller, sleeve, transport screw and
mixing mill.
• The developer is mixed and charged by the transport screw and the mixing mill
where it is transferred to the developer sleeve. The developer on the sleeve
forms a brush by the magnetic force of the magnetic roller, and makes contact
with the electrostatic latent image on the drum. Toner is attracted to the areas
of the drum which have been discharged by the laser.
• The doctor blade regulates the height of the magnetic brush which is formed
by the developer which is attracted to the sleeve of the magnetic roller.
• The TDC sensor is an inductance type sensor used to measure the ratio of
toner to developer.
• A twin field magnetic roller forms 2 pole peaks facing the drum, to enhance
developing performance.
• A dust collector vacuum duct is provided under the developer unit to prevent
toner dusting. The dust collector is duct connected to the dust collector fan
mounted on the machine frame which vacuums the scattered toner to prevent
toner dusting under the developer unit.
Part description
1 Magnet roller
2 Doctor blade
3 Mixing mill
4 Transport screw
5 TDC sensor
6 Dust collector duct
7 Magroll spacer
8 Drum spacer
Drum
2-8
Function
Transports developer to photo receptor.
Controls height of developer on sleeve.
Mixes and charge developer and transport it to
magnet roller.
Mixes developer and transports to mixing mill.
Measures toner density.
Collects scattered toner dust.
Corona
1
2
4
3
7
6
5