Toshiba e-STUDIO353 - Heating Principle Of Ih Heater

13 - 5 e-STUDIO350/352/353/450/452/453
FUSER UNIT / PAPER EXIT SECTION
13
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13.4.2 Heating principle of IH Heater
The magnetic eld is generated by applying a high frequency current to the IH coil inside the fuser
roller,whichthengeneratestheeddycurrentinit.Whentheeddycurrentows,theJouleheatisgen-
erated by the resistance element of the fuser roller, which is then heated. In the IH coil method, the
thermalefciencyishigherthanthelampmethodbecausethefuserrollerisdirectlyheated.
B
A
Current flowing on the surface of the fuser roller
Current flowing inside the
fuser roller
Eddy currentHigh frequency
magnetic field
IH coil
High frequency
power source
[
Image of current flowing from A to B
]
D1
T1
C1
C2
CPU
Voltage
input
I/F circuit on LGC board
Monitoring input current
Current input
Monitoring input current
Control circuit high frequency current
Smoothing circuit
Tr1
(
IGBT
)
IH coil
Fuser roller
IGBT
drive
[
Block diagram of high frequency power supply
]
Photocoupler
Fig. 13-402
Fig. 13-403