FIXATION DEVICE AND IMAGE FORMING APPARATUS

• Main Author: TAKAGI OSAMU
• Format: Patent
• Language: English; Japanese
• Published: 22.03.2018
• Subjects: CINEMATOGRAPHY; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; HOLOGRAPHY; MAGNETOGRAPHY; PHOTOGRAPHY; PHYSICS

PROBLEM TO BE SOLVED: To provide a fixation device capable of intensively and stably heating a paper passing area to achieve the improvement of fixation quality and the energy saving.SOLUTION: A fixation device includes: determination means for determining the size of a medium having a toner image formed thereon; a rotor having an endless shape; a plurality of heat generating members which have the same length in the medium conveyance direction, are separated into various lengths in the direction perpendicular to the conveyance direction, are formed in such a manner that the creepage distance between electrodes formed on both ends and the creepage distance or spatial distance between boundaries after the separation are adjusted to be a prescribed value, and are disposed to contact with the inside of the rotor; and a switching part for individually switching the electrification of the electrodes of the heat generating members. The fixation device comprises: heating means for heating a medium; pressure means that comes into pressure contact with the heating means at the positions of the plurality of heat generating members to form a nip, and holds and conveys together with the heating means the medium in the conveyance direction; and heating control means for selecting by the switching part a heat generating member corresponding to a position where a medium passes and electrifying the heat generating member to control the heating.SELECTED DRAWING: Figure 6 【課題】通紙領域に対する集中的かつ安定した加熱を可能とし、定着品質の向上と省エネルギー化を達成する。【解決手段】定着装置は、トナー像が形成された媒体の大きさを判定する判定手段と、エンドレス形状の回転体と、媒体の搬送方向における長さが同一で、搬送方向と直角方向において複数種の長さに分割され、両端に形成された電極間の沿面距離、分割後の境界部分における沿面距離または空間距離が所定の値に調整されて形成され、回転体の内側に接触して配置された複数の発熱部材と、発熱部材の電極に対する通電を個別に切替える切替部とを有し、媒体を加熱する加熱手段と、加熱手段に複数の発熱部材の位置で圧接してニップを形成し、加熱手段とともに媒体を搬送方向に挟持搬送する加圧手段と、媒体が通過する位置に対応する発熱部材を切替部により選択して通電し、加熱を制御する加熱制御手段と、を備える。【選択図】図６