| 摘要 |
PROBLEM TO BE SOLVED: To reduce heat generation in a paper non-passing region and thereby prevent the damage of components such as an offset, a fixing film, a pressing roller and a film guide. SOLUTION: In the front surface side of a ceramic recording material 1 of a heating body A, PTC patterns (positive temperature coefficient characteristic patterns) 3A, 3B each having a length equal to that of a heating element pattern are formed on both sides of the heating element pattern 2A, and a current is carried to the heating element pattern 2A through the PTC patterns 3A, 3B. In the case that the paper passing of a small-sized transferring material is continued, when the temperature of a paper non-passing region is about to exceed 230 deg.C, the resistance in the paper non-passing region is increased nearly tenfold by the PTC patterns 3A, 3B, and the amount of current at both the end parts of the heating element pattern 2A is reduced to 1/10 as much as that of the center, so that the heating value at those parts of the heating element pattern 2A is also reduced to 1/10. As a result, excessive heat feeding in the paper non-passing region is eliminated and the balance with natural heat radiation is established so that the temperature in the paper non-passing region does not rise above 230 deg.C.
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