Patent ID: 7738828

Claim:
A fixing devise comprising: a cylindrical base material, with a variation in outer diameter within about ±0.5% when the cylindrical base material is in a circular cylinder tube shape having rigidity; an elastic layer that is disposed on or above the base material and with a variation in thickness within about ±5%; and a surface layer that is disposed on or above the elastic layer, with a variation, along a circumferential direction of the base material, in thickness of the surface layer within about ±5% and with a surface elongation percentage which increases from a center portion toward both end portions in a widthwise direction of the base material, wherein a ratio (B/A) of a maximum value (B) to a minimum value (A) of the elongation percentages of the surface layer in the widthwise direction is in a range of about 1.25 to about 2.5, and the maximum value of the thickness of the surface layer in the widthwise direction is about 50 μm or less, and the minimum value of the thickness of the surface layer in the widthwise direction is about 20 μm or more.