Patent ID: 6980764

Claim:
A belt-type fixing device for fixing a toner image on a paper, the belt-type fixing device comprising: an endless-sheet-like belt member, a pressurizing roller which has an elasticity and on which the paper is passed through a fixing nip that is contact part between the pressurizing roller and an outer circumferential surface of the belt member, a nip forming member that is harder than the pressurizing roller, that is positioned inside the belt member, that relatively presses the belt member against the pressurizing roller, and that has a pressing surface opposite to the pressurizing roller and formed of a curved surface extending along an outer circumferential surface of the pressurizing roller, and a spring that provides the belt member with a tension such that, for a tension load W [N] and a width L [m] of the belt member, W/L is in a range from 18.0 to 107.9 [N/m].