Fixing device and image forming apparatus incorporating same

A fixing device comprising:

• a rotator having flexibility and a sleeve form, the rotator including an inner portion having a sliding surface, the inner portion having an elastic power of 55% or more, wherein the sliding surface of the rotator has a valley void volume of 0.01 ml/m2 or more;
• a secured member being disposed inside a loop of the rotator, the secured member having a slide surface on which the sliding surface of the rotator is to slide, the slide surface having a smaller surface roughness in a sliding direction of the rotator than a surface roughness of the sliding surface in the sliding direction of the rotator;
• a pressure rotator configured to press the rotator against the secured member and form a nip between the rotator and the pressure rotator;
• and
• lubricant provided between the rotator and the secured member.

A fixing device comprising:

• a rotator having flexibility and a sleeve form, the rotator including an inner portion having a sliding surface, the inner portion having an elastic power of 55% or more, wherein the sliding surface of the rotator has a kurtosis equal to or smaller than three;
• a secured member being disposed inside a loop of the rotator, the secured member having a slide surface on which the sliding surface of the rotator is to slide, the slide surface having a smaller surface roughness in a sliding direction of the rotator than a surface roughness of the sliding surface in the sliding direction of the rotator;
• a pressure rotator configured to press the rotator against the secured member and form a nip between the rotator and the pressure rotator;
• and
• lubricant provided between the rotator and the secured member.