| 摘要 |
PURPOSE:To enable a high printing force to be generated, by a method wherein a repulsive force obtained by collision with a repulsive member is imparted to a electrostrictive vibrator. CONSTITUTION:When a driving voltage is impressed on a electrostrictive element 10B of the electrostrictive vibrator 10 by a driving circuit 11, the element 10B is contracted, so that the vibrator 10 is bent and is displaced in the direction from a position A before impressing the voltage to a position B at a velocity v1 to collides against the repulsive member 13. Simultaneously, the driving voltage is cut off, so that due to the repulsion on collision against the member 13 and the elasticity of the vibrator 10 itself, the vibrator 10 is returned toward the position A at a velocity -ev1 to give an impact on a non-printing side end of a printing wire 5. The velocity of the vibrator 10 at this time is -(ev1+v2). As a result, the vibrator 10 remains stationary at the position A, while the wire 5 starts to solely move on receiving the impact from the vibrator 10, and the tip thereof protrudes from a tip bearing 7 to give an impact on an ink ribbon and a printing paper. After the impact, the wire is returned by the repulsive forces of the ribbon and the paper and an elastic force of a return spring 8 to make contact with a stopper 9. |
