Toshiba e-STUDIO281c Service Manual page 344

9) Main thermistor (THM2) / Sub thermistor (THM3)
This thermistor detects the temperature of the fuser belt to maintain it in a certain temperature range
(actually around 180°C) between the lower limit causing the poor fusing and the upper limit causing
the high temperature offsetting. When the temperature of the fuser belt is lower than the preset tem-
perature, it turns ON the power supply to the IH coil (IH-COIL), and when it is higher than the preset
temperature, it cuts off the supply. The main thermistor (THM2) detects the temperature of the cen-
ter part of the fuser belt and the sub thermistor (THM3) detects the temperature of the both ends of
the fuser belt. It also detects the slight difference of the temperatures at the center and both ends of
the fuser belt to control the balance of ON/OFF of the center/side parts of IH coil to keep the fuser
belt at a certain temperature.
10)Front edge thermistor (THM1)
It detects the temperature abnormality at the both ends of the fuser belt. This area may be over-
heated without heat absorption by paper since paper does not pass through this area. This ther-
mistor is not related to the temperature control of the fuser belt.
11)Fuser thermostat (THMO1)
The thermostat cuts off the power supply to the IH coil (IH-COIL) by opening itself if the fuser belt
becomes abnormally hot as a result of the problem such as thermistor malfunction. The thermostat
for this equipment is used to prevent abnormal operation. When the thermostat detects any abnor-
mality, it must be replaced as well as the other damaged parts in the fuser unit.
12)Exit sensor (S40)
This sensor detects the arrival of the leading or trailing edge of the paper at the exit roller of the fuser
unit. It also detects paper jams in the fuser unit paper exit section and trailing edge of paper turned
over for duplex printing.
13)Exit motor (M7)
The exit motor (M7) is a stepping motor which drives the exit roller and bridge unit (option). It
reduces the transport speed down to the range from 1/2 to 1/3 according to the type of paper such
as OHP film or thick paper in color modes.
14)Exit roller
This roller transports the paper from the fusing section to the inner tray, paper exiting options or the
ADU and is driven by the exit motor (M7).
15)Discharge brush
It is installed with the pressure roller contacting it in order to keep the surface potential on the roller
even.
e-STUDIO281c/351c/451c FUSER UNIT / PAPER EXIT SECTION
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June 2005 © TOSHIBA TEC