FIXING DEVICE AND IMAGE FORMING APPARATUS

• Main Authors: YUASA SHUTARO, YAMAJI KENSUKE, KANDA YUTA, KUBOTA KEISUKE, HIROSE FUMIHIRO, OGINO JUN, OKAMOTO MASAMI
• Format: Patent
• Language: English; Japanese
• Published: 05.04.2018
• Subjects: CINEMATOGRAPHY; ELECTROGRAPHY; ELECTROPHOTOGRAPHY; HOLOGRAPHY; MAGNETOGRAPHY; PHOTOGRAPHY; PHYSICS

PROBLEM TO BE SOLVED: To provide a fixing device capable of suppressing the occurrence of streak-like wrinkles on a recording medium after passing through a fixing nip and to provide an image forming apparatus.SOLUTION: The fixing device includes a separation member such as a separation auxiliary member 48 which is arranged in a position not in contact with a pressure member such as a pressure roller 45 through a fixing belt 43 on the downstream side of a nip forming member such as a fixing roller 41 in the moving direction of the recording medium and comes into contact with the inner peripheral surface of the fixing belt 43, to make the curvature of the fixing belt 43 large. A pressing member 49 which comes into contact with the inner peripheral surface of the fixing belt 43, to press the fixing belt 43 is arranged between the nip forming member and the separation member in the moving direction of the recording medium. The fixing device includes contact/separation means such as a pressurizing and depressurizing mechanism which brings/separates the pressure member into contact with/from the fixing belt 43. The operation condition of a pre-heating operation for thermally expanding the pressure roller is changed on the basis of an environmental temperature.SELECTED DRAWING: Figure 2 【課題】定着ニップ通過後の記録媒体にスジ状のしわが生じるのを抑制することができる定着装置および画像形成装置を提供する。【解決手段】定着ローラ４１などのニップ形成部材よりも記録媒体の移動方向下流側で、定着ベルト４３を介して加圧ローラ４５などの加圧部材と接触しない位置に配置され、定着ベルト４３の内周面に当接して、定着ベルト４３の曲率を大きくする分離補助部材４８などの分離部材を備えている。また、記録媒体の移動方向において、ニップ形成部材から分離部材までの間に、定着ベルト４３の内周面に当接して定着ベルト４３を押さえる押さえ部材４９が配置されている。また、加圧部材を前記定着ベルト４３に対して接離させる加圧脱圧機構などの接離手段を備えている。そして、加圧ローラを熱膨張させるプレ加熱動作の動作条件を、環境温度に基づいて変更するようにした。【選択図】図２