FIXING DEVICE, AND IMAGE FORMING APPARATUS INCLUDING THE FIXING DEVICE

PROBLEM TO BE SOLVED: To provide a fixing device that is excellent in detecting damage occurring to a rotating body having conductivity.SOLUTION: A fixing device causes an alternating current to flow in an exciting coil 3 to generate an alternating magnetic flux in a magnetic core material 2 and thereby heating a cylindrical rotating body 1 by electromagnetic induction. The fixing device comprises: first induction current detection coils 5A, 5B, 5C, and 5D that are wound in a revolving direction of the magnetic core material along the axial direction of the rotating body outside the exciting coil; and second induction current detection coils 5A', 5B', 5C', and 5D' that are wound in the revolving direction of the magnetic core material along the axial direction of the rotating body outside the exciting coil, symmetrically with the first induction current detection coils with respect to the center of the axial direction of the rotating body of the magnetic core material. The fixing device determines the state of damage of the rotating body on the basis of a difference in current value of the induction current induced to the first induction current detection coils and second induction current detection coils when causing the alternating current to flow.SELECTED DRAWING: Figure 4 【課題】導電性を有する回転体に発生した破損の検知に優れる定着装置を提供すること。【解決手段】励磁コイル３に交番電流を流し磁性芯材２に交番磁束を発生させて筒状の回転体１を電磁誘導加熱させる定着装置において、前記励磁コイルの外部で前記回転体の軸方向に沿って前記磁性芯材の周回方向に巻かれた第１の誘導電流検出コイル５Ａ，５Ｂ，５Ｃ，５Ｄと、前記磁性芯材の前記回転体の軸方向の中央に対して前記第１の誘導電流検出コイルと対称に前記励磁コイルの外部で前記回転体の軸方向に沿って前記磁性芯材の周回方向に巻かれた第２の誘導電流検出コイル５Ａ´，５Ｂ´，５Ｃ´，５Ｄ´と、を有し、前記交番電流を流したときに前記第１の誘導電流検出コイルと前記第２の誘導電流検出コイルに誘導される誘導電流の電流値の差に基づいて前記回転体の破損状態を判断することを特徴とする。【選択図】図４