US Patent 7275481 Printer

A printer of the present invention includes a timing belt passed over drive pulleys, each of which is mounted on a particular print drum, via phase adjusting means and deflection pulleys or rotary members. The deflection pulleys are rotatable in contact with the rear surface of the timing belt. The timing belt has its rear surface ground to have uniform thickness. The printer is free from the deviation of relative phase between the rotary members and offset ghosts ascribable to the irregular thickness of the timing belt, while preserving the low-cost configuration of timing belt connection.