Patent ID: 8346149

Claim:
A fixing device that fixes a toner image in place on a recording medium, the fixing device comprising: a first member extending along a first longitudinal axis, the first member including a first elastic layer having a thickness that varies along a length of the first longitudinal axis to define at least one first convex portion curving outward and at least one first concave portion curving inward with respect to the first longitudinal axis; and a second member extending along a second longitudinal axis parallel to the first longitudinal axis, the second member including a second elastic layer having a thickness that varies along a length of the second longitudinal axis to define at least one second convex portion curving outward and at least one second concave portion curving inward with respect to the second longitudinal axis, wherein at least one of the first and second members is heated, and at least one of the first and second members is pressed against the other, with the first convex portion engaging the second concave portion and the first concave portion engaging the second convex portion, to define a fixing nip therebetween through which the recording medium is passed to fix the toner image under heat and pressure, and wherein first adjacent longitudinal ends of the first and second members, respectively, are aligned with each other, and second adjacent longitudinal ends of the first and second members, respectively, are displaceable along the respective first and second longitudinal axes.