Sharp AL-1611, Руководство по обслуживанию

Страница: 26 / 140

AL-1611/AL-1622 OPERATIONAL DESCRIPTIONS
6 – 7
B. Brief descriptions of operations
This machine allows two ways of paper feed system: cassette paper
feed and manual paper feed.
The cassette of universal type is employed to hold 250 sheets. The
front loading system allows to attach or detach the cassette from the
front of the machine.
Paper size can be selected by the user.
Since this model is not equipped with the automatic paper select func-
tion, paper size detection is not performed.
(1) Cassette paper feed operation
Select the cassette and press the START button, and the paper feed
roller solenoid will be turned on and the paper feed clutch will be
released.
The drive power of the main motor is transmitted through the paper feed
roller clutch to the paper feed roller, rotating the paper feed roller and
feeding paper.
(2) Manual paper feed tray operation
Select the manual paper feed tray and press the START button, and the
manual paper feed roller will be turned on to bring the paper feed roller
in contact with paper and lift the shutter simultaneously.
The drive power of the main motor is transmitted through the manual
paper feed roller clutch to the manual paper feed roller, rotating the
manual paper feed roller and feeding paper.
(3) Resist roller
In order to make synchronization between the paper lead edge fed from
the paper feed port and the image lead edge, the roller is kept station-
ary for a certain time after the paper reaches at the roller towarp the
paper a little.
When the paper is warped to a certain level, the resist roller solenoid is
turned on to release the resist roller clutch.
The drive power of the main motor is transmitted through the resist
roller clutch to the resist roller, rotating the resist roller and feeding
paper.
6. FUSING SECTION
A. Basic composition
(Top view)
B. Heat roller
A pressure roller is used for the heat roller and a silicone rubber roller is
used for the lower heat roller for better toner fusing performance and
paper separation.
C. Separator pawl
Four separator pawls are used on the upper heat roller. The separator
pawls are teflon coated to reduce friction with the roller and prevent a
smear on the paper caused by the separator pawl.
D. Thermal control
1) The heater lamp, thermistor, main PWB, DC power supply PWB,
and triac within the power supply unit are used to control the tem-
perature in the fuser unit. To prevent against abnormally high tem-
perature in the fuser unit, a thermostat is used for safety purposes.
2) The surface temperature of the upper heat roller is set to 180°C ~
195°C. The surface temperature during the power save mode is set
to 100°C.
5
4
3
2
1
8
6
7
1 Before-fusing
paper guide Guides the paper transported from the process
section to the fusing unit.
2 Upper heat
roller Applies heat and pressure to the paper to fuse.
3 Thermistor Detects the surface temperature of the upper
heat roller.
4 Thermostat Stops power supply to the heat roller in case of
an abnormally high temperature of the heat
roller.
5 Separation
pawl Separates the print paper from the upper heat
roller.
6 POD1 Detects that the paper has been transported
from the fusing section.
7 Heater lamp Heats the heat roller.
8 Lower heat
roller Applies a pressure to the paper together with
the upper heat roller.
2
7
5 8
4
3
Safety device
(thermal breaker, thermal
fuse)
Triac (in the
power supply unit)
Heated by the
heater lamp.
(950W )
The surface temperature
of the upper hea t roller
is sensed by the thermistor.
Level of the thermistor is
controlled by the main PWB.
With the signal from the
main PWB, the triac is
controlled on and off.
(power supply PWB )