Toshiba e-STUDIO 206, Service Manual

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12
© February 2007 TOSHIBA TEC CORPORATION All rights reserved e-STUDIO166/206
DEVELOPMENT SYSTEM
12 - 3
12.3 Functions
12.3.1 Function of each unit
[ 1 ] Developer unit
• Developer material
This consists of carrier and toner. The carrier is electrically conductive ferrite whose particle size is
30-100
" m, and the toner is resin whose particle size is 5-20 " m. The developer material requires a
periodic replacement since it deteriorates with long-term use.
• Mixers-1, -2 and -3
Mixing the developer material generates a friction of the carrier and the toner. The carrier is then
positively charged and the toner is negatively charged, and the charged carrier and toner adhere on
the drum surface by their static electricity. The mixer-3 is mounted exclusively for the recovered
toner to mix it in a sufficient period of time.
• Developer sleeve (Magnet roller)
This aluminum roller includes a magnet inside. The developer sleeve absorbs the developer mate-
rial using this magnet to form a magnetic brush. The magnet is fixed therefore the only sleeve is
rotated. This rotation makes the magnetic brush of the developer sleeve sweep over the drum sur-
face, and thus development is performed.
• Doctor blade
This controls the amount of the developer material transported from the developer sleeve so that the
magnetic brush of the developer material can properly contact with the drum surface.
• Auto-toner sensor (S6)
To print out normal images, a constant ratio of the carrier and the toner in the developer material (=
toner density) must be maintained. The auto-toner sensor (S6) detects the content ratio of the toner
in the developer material with its magnetic bridge circuit. When this sensor detects the insufficient
status of the toner, it drives the toner motor (M2) to supply the toner from the toner cartridge.
• Drum thermistor (THMS4)
This is installed in the developer unit to detect the ambient temperature of the drum.
• Recovered toner supply mechanism (Toner recycling auger)
The recovered toner, transported from the drum cleaner, is then transported into the developer unit
by the toner recycling auger mounted on the front side of this unit. The drive of the toner recycling
auger is transmitted from the mixer-3.
[ 2 ] Toner cartridge
This is filled with the toner and this supplies the toner to the developer unit by the drive of the toner
motor (M2). The toner cartridge in this equipment mounts the toner cartridge PC board (CTRG), and
the data identifying recommended TOSHIBA toner cartridges and the counter values determining that
the cartridge is nearly empty are written in this board. These data are read out by the toner cartridge
interface PC board (CTIF) in this equipment, and data related to toner supply are also written in the
toner cartridge PC board (CTRG). The toner cartridge interface PC board (CTIF) also detects whether
the toner cartridge is installed or not.
[ 3 ] Toner motor (M2)
This drives the toner cartridge with gears.