The present invention while reducing the thickness of the peripheral wall of the heating roller, to prevent deformation of the heating roller.
A fixing device 13 includes a cylindrical heating roller 31, provided inside the heating roller 31, the heating unit 32 for heating the heating roller 31, is pressed against the heating roller 31, the recording sheet is pinched the nip region N and pressure roller 33 to be formed between the heating roller 31, provided inside the heating roller 31, an auxiliary roller 34 which is pressed against the pressure roller 33 via the circumferential wall of the heating roller 31 the provided, the outer peripheral shape of the auxiliary roller 34 which is pressed against the inner circumferential surface of the heating roller 31 is reversed to the outer diameter of about the auxiliary roller 34 closer to the axially central portion than the axial outer sides of the auxiliary roller 34 becomes smaller It has been the crown type.
.FIELD 2