Patent ID: 8824930

Claim:
A synchronized drive unit, comprising: a drive member comprising a pulley; a driven member comprising a pulley; a relay member comprising a pulley, configured to transmit a power; and a timing belt hung around the drive and driven members through the relay member with tension and configured to rotate the drive and driven members in synchronization, wherein the timing belt is formed of plural narrow belts parallely placed in a rotational axis direction of the pulley, each of the plural narrow belts includes: a drive narrow belt hung around the drive member and the relay member with tension; and a driven narrow belt hung around the relay member and the driven member, wherein the plural narrow belts are located such that eccentric components of the drive narrow belts transmitted to the driven member through the relay member and those of the driven narrow belts transmitted thereto counteract each other on the driven member in a rotational direction, wherein each of the timing belts includes a plurality of the marks, and wherein one of the plurality of marks identifies rotational direction, and each of the plurality of marks is assembled in a same rotational direction.