| 摘要 |
PURPOSE:To contrive a smaller size, a higher efficiency and reductions in the number of component parts and weight, by a construction wherein a rotor connected directly to a platen shaft is pressed against an elastic body, the elastic body is provided with a piezoelectric element for generating an elastic surface wave in the surface of the body, and a detecting means for the rotating quantity of the rotor is provided. CONSTITUTION:A platen 6 with a printing paper 7 set thereon is directly connected to a driving mechanism through the platen shaft 5, and is driven to rotate. The shaft 5 is provided with a gear for detecting the rotating quantity thereof, and the rotating quantity is detected by a magnetic sensor 9. The rotating quantity thus detected is fed back to a driving system by a controlling mechanism to perform feedback control. By the surface wave generated by the piezoelectric element 1, a driving force for low-speed, high-efficiency and high-torque rotation is exerted on the rotor 3. Accordingly, there is no need for gear trains or timing belts, so that not only a smaller device size but higher reliability and lower cost can be achieved. |
