Patent ID: 6782232
Filing Date: 2004-08-24
Classification: G03G

Abstract:
An image forming apparatus comprising a fixing unit which includes a heat section having a resilient body and a release layer that covers said resilient body, and a press section having a resilient body and a release layer that covers said resilient body and pressed by said heat section, and which heats and fixes a transfer medium at a nip portion as a press contact portion of said two sections, whereinat least one of the following three conditions is satisfied: (a) a tensile strength of said resilient body of said heat section upon a lapse of an arbitrary use time is higher than an initial tensile strength thereof or is not lower than the initial tensile strength by not less than 0.5 MPa, (b) a relationship (H1âˆ’H0)âˆ’(h1âˆ’h0)&lE;0 is always satisfied where H0 is the initial surface hardness of said heat section, h0 is the initial surface hardness of said press section, and H1 and h1 are the surface hardnesses of said heat section and said press section, respectively, upon a lapse of the arbitrary use time, and (c) a modulus of impact resilience of said resilient layer of said heat section upon a lapse of the arbitrary use time is higher than a modulus of initial impact resilience thereof before start of use, or is not lower than the modulus of initial impact resilience by not less than 10%.