Patent ID: 7056245
Filing Date: 2006-06-06
Classification: B41J,F16H

Abstract:
1. A belt driving apparatus comprising: a toothed pulley; an endless toothed belt wound on said pulley, wherein a first surface of said toothed belt comprises teeth corresponding to teeth of said pulley and a second surface of said toothed belt is substantially smooth; an auxiliary roller for holding said toothed belt in a gap defined by said pulley and said auxiliary roller; a roller holding unit for holding said pulley and said auxiliary roller to be able to respectively rotate on axes of said pulley and said auxiliary roller and maintaining said gap between said pulley and said auxiliary roller; and an urging member for urging said roller holding unit in a direction to said toothed belt around said pulley in order for said auxiliary roller held by said roller holding unit to provide a tension to said toothed belt, wherein a distance between centers of axes of said pulley and said auxiliary roller is shorter than a sum of a radius of said auxiliary roller, a radius of said pulley, which is determined to be a distance from the center of said axis to a top end of a tooth of said pulley, and a distance from said second surface to a top end of a tooth of said toothed belt.