| 摘要 |
In an external heating type induction heating device in which a magnetic field producing means is arranged in the outer circumferential portion of a heating roller 1, two heat generating layers, namely a conductive shaft 1 a and a surface heat generating layer 1 c, are provided in the heating roller 1, and the surface heat generating layer 1 c is formed having a thickness through which passes a portion of an alternating magnetic field, and the conductive shaft 1 a at a center of the heating roller 1 is heated by a portion of the alternating magnetic field produced by the magnetic field producing means passing through the surface heat generating layer 1 c to link to the conductive shaft 1a present at the center of the roller, thereby preventing a drop in a surface temperature of the heating roller 1. |
