HEATING APPARATUS, FIXING APPARATUS, AND IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED: To provide a heating apparatus configured to instantaneously detect a crack of a heater, and to cut off power to be supplied to a heating resistor at the time of cracking.SOLUTION: A heating apparatus includes: electrodes 29, 30 arranged in a longitudinal direction of a substrate 27; power-supply sections 29a, 30a arranged at one longitudinal end of the substrate 27 to supply power to the electrodes 29, 30; a heating resistor 26 electrically connected between the electrodes 29, 30 in a lateral direction of the substrate 27; and resistance detection means which detects a resistance value R of the heating resistor 26. When the resistance value R of the heating resistor 26 detected by the resistance detection means is larger than a predetermined resistance value R, power to be supplied to the heating resistor 26 is cut off. 【課題】 本発明は、ヒータの割れ検知を瞬時に行い、割れた瞬間に発熱抵抗体への給電を遮断できる加熱装置を提供する。【解決手段】 基板27の長手方向に沿って設けられた電極29，30と、該基板27の長手方向における一方の端部に設けられ、該電極29，30にそれぞれ給電する給電部29ａ，30ａと、該基板27の短手方向において電極29，30間に電気的に接続された発熱抵抗体26と、該発熱抵抗体26の抵抗値Ｒを検知する抵抗検知手段と、を有し、該抵抗検知手段により検知した発熱抵抗体26の抵抗値Ｒが、所定の抵抗値Ｒよりも大きい場合は、発熱抵抗体26への給電を遮断することを特徴とする。【選択図】 図４