Heating Principle Of Ih Heater - Toshiba e-STUDIO350 Service Manual

13.4.2 Heating principle of IH Heater

The magnetic field 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 flows, the Joule heat is generated by
the resistance element of the fuser roller, which is then heated. In the IH coil method, the thermal effi-
ciency is higher than the lamp method because the fuser roller is directly heated.
High frequency
power source
[ Block diagram of high frequency power supply ]
November 2003 © TOSHIBA TEC
B
A
IH coil High frequency
magnetic field
[ Image of current flowing from A to B ]
Fig. 13-402
Smoothing circuit
C1
D1
T1
Current input
Monitoring input current
Monitoring input current
Fig. 13-403
13 - 5
Current flowing on the surface of the fuser roller
Eddy current Current flowing inside the
fuser roller
Control circuit high frequency current
Fuser roller
IH coil
( IGBT )
C2
Tr1
IGBT
drive
CPU
Voltage
input
I/F circuit on LGC board
e-STUDIO350/450 FUSER UNIT / PAPER EXIT SECTION
13