| 摘要 |
PROBLEM TO BE SOLVED: To quickly uniformize temperature nevertheless a temperature change of only part of a heating element, by forming a pair of electrodes on a base board, and providing film-like resistant heating elements, having a positive electric resistance-temperature characteristic in parallel to the electrodes. SOLUTION: A pair of electrodes 4 are formed on a heat resisting insulating base board 2, and film-like resistant heating elements 3, having a positive 'electric resistance'-temperature characteristic, are provided in parallel on the electrodes 4, when, for instance, part of the board 2 is cooled to lower the temperature of the part, the elements 3 have a positive 'electric resistance'- temperature characteristic for changing a resistant value of the elements 3 into a direction same as that of am change of temperature, conseqently, the resistant value of the elements 3, in the portion where the temperature is lowered, is also lowered. Resultingly, an electric current, more than that in the other elements 3, flows in the heating elements 3, where temperature is lowered out of the heating elements. Consequently, since electric power concentrates in a portion, where much heat is needed by cooling, heating quantity can be quickly replenished to the portion to hasten temperature rise. Also, the temperature rise in part of the board 2 actuates the elements 3 reversely. |
