FIXING UNIT AND IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED: To provide a fixing unit and an image forming apparatus that can maintain the temperature of a heating roller below an allowable range.SOLUTION: A fixing unit comprises: a plurality of heaters (12A and 12B) that heat a medium to be conveyed in a conveyance direction (x); guides (13A, 13B, 14, and 15) that movably support each of the plurality of heaters (12A and 12B) in a width direction (y) orthogonal to the conveyance direction (x); and driving force transmission mechanisms (18A, 18B, 19, 20, and 22) that transmit a driving force for moving the plurality of heaters (12A and 12B) along the guides (13A, 13B, 14, and 15) to each of the plurality of heaters so as to switch the length of a heating range in the width direction (y) of the plurality of heaters.SELECTED DRAWING: Figure 2 【課題】ヒートローラの温度を許容範囲以下に維持することを可能にする定着器及び画像形成装置を提供する。【解決手段】定着器は、搬送方向（ｘ）に搬送される媒体を加熱する複数のヒータ（１２Ａ，１２Ｂ）と、前記複数のヒータ（１２Ａ，１２Ｂ）の各々を、前記搬送方向（ｘ）に直交する幅方向（ｙ）に移動可能に支持するガイド（１３Ａ，１３Ｂ，１４，１５）と、前記複数のヒータ（１２Ａ，１２Ｂ）を前記ガイド（１３Ａ，１３Ｂ，１４，１５）に沿って移動させる駆動力を前記複数のヒータの各々に伝えることで、前記複数のヒータによる前記幅方向（ｙ）の加熱範囲の長さを切り替える駆動力伝達機構（１８Ａ，１８Ｂ，１９，２０，２２）と、を備える。【選択図】図２