Patent ID: 8867963

Claim:
A belt driving mechanism, comprising: a driving pulley; a driven pulley; a looped transmission belt extended over the driving pulley and the driven pulley; a first holding member that bearing-supports and holds the driving pulley; a second holding member that bearing-supports and holds the driven pulley and is combined with the first holding member; and a biasing member that biases the first holding member and the second holding member so as to be separated, in a state in which the first holding member and the second holding member are combined wherein the second holding member comprises a plurality of walls, each wall of the second holding member conforms to shape of the first holding member and accommodates an entirety or part of the first holding member, and the plurality of walls of the second holding member substantially encloses the exterior of the first holding member in a state where the first holding member substantially resides inside the second holding member.