FIXING DEVICE AND IMAGE FORMING APPARATUS

To obtain stable fixing performance over a long period.SOLUTION: A fixing device heats and fixes an image on a recording material with a first rotating body heated by a heater, while sandwiching and conveying the recording material between the first rotating body and a second rotating body at a nip part. A holder member holding the heater is provided on the side of the second rotating body in a thickness direction perpendicular to both a longitudinal direction and a short direction of the heater at the nip part, and has a first surface that supports the heater, a second surface that is provided on the opposite side of the first surface in the thickness direction and supported by a support member on the upstream side and the downstream side of the first surface in the short direction, and rib parts that are provided projected on the second surface and extend in the short direction over a range in which at least the first surface is provided with respect to the short direction.SELECTED DRAWING: Figure 7 【課題】長期間に亘って安定した定着性能を得る。【解決手段】定着装置は、ニップ部で第１の回転体と第２の回転体の間に記録材を挟持して搬送しながら、ヒータによって加熱された第１の回転体により記録材上の画像を加熱して定着させる。ヒータを保持するホルダ部材は、ニップ部における前記ヒータの長手方向及び短手方向の双方に垂直な厚み方向における第２の回転体の側に設けられ、ヒータを支持する第１の面と、厚み方向における第１の面の反対側に設けられ、短手方向における第１の面の上流側と下流側で支持部材に支持される第２の面と、第２の面に凸設され、短手方向に関して少なくとも第１の面が設けられた範囲に亘って短手方向に延びたリブ部と、を有する。【選択図】図７