| 摘要 |
<p>A planar heating element in which a plurality of electrode coating members (4) respectively coating electrodes (3) are attached to a planar heating resistor sheet (2) at prescribed intervals. In each electrode coating member (4), at least the vicinity of the electrode (3) is constituted of a PTC layer having a positive temperature coefficient characteristic that the electrical resistance value of the PTC layer increases as the temperature rises. The sheet (2) does not have a positive temperature coefficient characteristic or has a positive temperature coefficient characteristic that the rise magnification of the sheet (2) is smaller than that of the PTC layer or the rise temperature of the sheet (2) is higher than that of the PTC layer at temperatures lower than the temperature at which the PTC layer exhibits the maximum rise magnification.</p> |
