Patent ID: 7523934

Claim:
A roller structure comprising: a first roller member, adapted to be fitted on a roller shaft, and comprising: at least one first portion, extending in a circumferential direction of the roller shaft, and having a first thickness in a radial direction of the roller shaft; and at least one second portion, extending in the circumferential direction, and having a second thickness in the radial direction which is greater than the first thickness; and at least one projection, formed on the first portion; and a second roller member, formed on the first roller member, and comprising: a third portion, opposing the second portion, and having a third thickness in the radial direction; and a fourth portion, opposing the first portion, and having a fourth thickness in the radial direction which is greater than the third thickness, wherein, the first roller member comprises a plurality of the first portions and a plurality of the second portions which are alternately arranged in an axial direction of the roller shaft, and wherein, the projection is formed on one of the first portions located between two of the second portions.