Toshiba DP-5550, Руководство по обслуживанию, Страница: 263 / 404

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TRANSFER/TRANSPORT UNIT
12 - 3
(9) Transfer/transport unit lock/unlock mechanism
The transfer/transport unit lock/release mechanism locks the unit in the equipment, and unlocks
it to draw the unit out to the front side when the paper jam is being cleared. The mechanism also
separates the transfer belt unit from the drum when the transfer/transport unit is drawn out. When
the unit is being drawn out, the mechanism can prevent the erroneous operation of the handle.
When the handle is turned clockwise (in a horizontal position), the unit can be drawn out. Insert
the transfer/transport unit into the equipment and turn the handle counterclockwise (in a vertical
position), so that the unit can be locked in. If the unit is not inserted completely, the handle
cannot be turned from the horizontal position.
(10) Transfer belt unit contact/release mechanism
When printing is completed or a paper jam has occurred, the mechanism releases the transfer
belt unit from the photoconductive drum. When printing is started, the mechanism contacts the
unit with the photoconductive drum.
The cam is rotated by the drive of the transfer belt cam motor (M15). Along with this rotation, the
lever on the rear side of the transfer/transport unit moves up and down, and thus the transfer belt
unit and the drum are contacted or released.
The phase of the cam is controlled by the transfer belt release detection sensor (S15) and the
transfer belt contact detection sensor (S16).
(11) Drum damp heater (DH3) (condensation prevention)
The drum damp heater (DH3) is installed under the transfer belt. The power is supplied to this
heater when the main switch (SW6) is turned OFF.
(12) Horizontal transport section
The paper reversed for duplex printing is transported to the horizontal transport section. At this
section, the paper is transported to the intermediate transport roller.
This section is driven by the fuser motor (M3) and controlled by the horizontal transport section
driving clutches-1 (CLT1), -2 (CLT2) and -3 (CLT3), and this drive is transmitted to the transport
roller. The horizontal transport sensors-1 (S19), -2 (S20) and -3 (S21) detect the paper transport.
12.3 General Description of Transfer Belt Unit Operation
1. The transfer belt unit is released from the photoconductive drum in the ready status.
2. The transfer belt is lifted, as well as rotated, and contacted with the photoconductive drum at the
start of printing.
3. The voltage of the high-voltage transformer is applied on the transfer belt through the power supply
roller.
4. Since the surface of the transfer belt is positively charged by a dielectric polarization, the belt
electrostatically attracts the paper from the drum. Thus the processes of transfer, separation and
paper transport are continuously performed.
5. The transfer belt unit is lowered, stops rotating, and waits at the released position from the
photoconductive drum after the completion of printing.