Functions - Toshiba e-studio 167 Service Manual

13.3 Functions

1) Pressure roller
The pressure roller is a sponge roller which assures the nip amount of the fuser roller. The pressure
from the spring presses the paper onto the fuser roller to fuse toner onto the paper efficiently.
2) Exit sensor (S5)
The exit sensor detects if the leading or trailing edge of the paper is passing through the pressure
roller and the fuser roller. This sensor is used for the detection of paper jams in the fuser/exit unit as
well.
3) Fuser roller
The fuser roller applies heat onto the paper and is heated by the heater lamps installed inside of the
fuser roller. The heat from this roller fuses toner onto the paper. The fuser roller in this equipment is
a thin roller which enhances heat conduction, and thus the warming-up time is shortened.
4) Heater lamp (LAMP1/LAMP2)
The heater lamps are halogen lamps to apply heat to the fuser roller. The fuser unit in this equip-
ment has 2 heater lamps (564W+564W) with different functions each other. One has a coil wound
up on its center and this part generates heat. The other one has coils wound up on its both ends and
these parts generate heat. The one has a coil on its center is called the center heater lamp (LAMP1)
and the one has coils on its both ends is called the side heater lamp (LAMP2).
The heater lamps are fixed on the inside of the fuser roller to heat it up. The heater lamps do not
rotate even when the fuser roller is rotating.
5) Sensor thermistor (THMS1) / Side thermistor (THMS2)
This thermistor detects the temperature of the fuser roller to maintain it in a certain temperature
range (actually around 170°C) between the lower limit causing the poor fusing and the upper limit
causing the high temperature offsetting. When the temperature of the fuser roller is lower than the
preset temperature, it turns ON the power supply to the heater lamps, and when it is higher than the
preset temperature, it cuts off the supply.
The center thermistor (THMS1) detects the temperature of the center part of the fuser roller, and the
side thermistor (THMS2) detects the temperature of one side of fuser roller and control the both
sides.
6) Edge thermistor (THMS3)
Both the ends of the fuser roller may be overheated without heat absorption by the paper since it
does not pass through this area. The edge thermistor (THMS3) detects any temperature abnormal-
ity of this area caused by overheating of the fuser roller. Therefore this thermistor is not used for
temperature control of the fuser roller.
7) Fuser thermostat (THMO1)
The fuser thermostat (THMO1) cuts off the power supply to the heater lamps (LAMP1/LAMP2) by
opening itself if the fuser roller becomes abnormally hot as a result of the problem such as ther-
mistor malfunction. The fuser thermostat (THMO1) for this equipment is used to prevent abnormal
operation. When the fuser thermostat (THMO1) detects any abnormality, it must be replaced as well
as the other damaged parts in the fuser unit.
8) Separation finger
Five separation fingers are installed above the fuser roller, in order to separate paper adhering to
each roller.
9) Exit roller
The exit roller, which transports the paper to the inner tray, is driven by the main motor (M3). It is
driven by the exit motor (M7) when the ADU (optional) is installed.
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e-STUDIO167/207/237
FUSER / EXIT UNIT
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