Fixing device

摘要

A fixing device includes: a cylindrical film; a nip forming member; and a back-up member for forming a nip. The nip forming member includes a projected portion. The projection amount of the projected portion is smaller in an end portion region positioned at an end portion of the projected portion with respect to a generatrix direction of the film than in a central region positioned at a central portion of the projected portion with respect to the generatrix direction, at least a part of the end portion region being inside a feeding region of a maximum-sized recording material usable in the fixing device. With respect to the recording material feeding direction, the width of the part of the projected portion inside the nip is broader in the end portion region than in the central region.

主权项

1. A fixing device for fixing an image on a recording material, comprising:
a cylindrical film; a nip forming member contacting an inner surface of said film; and a back-up member configured to form a nip in cooperation with said nip forming member via said film, the nip being a contact region where said film and said back-up member contact each other to feed the recording material and being a portion extending from an entrance where the recording material in an unnipped state enters the contact region to an exit where the recording material comes out of the contact region, wherein said nip forming member includes a projected portion, at the exit, projected toward said back-up member, wherein at least a part of said projected portion with respect to a recording material feeding direction is inside the nip and contacts the inner surface of said film, wherein the projection amount of said projected portion is smaller in an end portion region positioned at an end portion of said projected portion with respect to a generatrix direction of said film than in a central region positioned at a central portion of said projected portion with respect to the generatrix direction, at least a part of the end portion region being inside a feeding region of a maximum-sized recording material usable in said fixing device, and wherein with respect to the recording material feeding direction, the width of the part of said projected portion inside the nip is broader in the end portion region than in the central region.