MECHANISM FOR ENLARGING FINE DISPLACEMENT IN PRINTING HEAD

摘要

PURPOSE:To attain a small-size printing head, by a method wherein an arm member is inclinedly displaced because of the buckling deformation of a plate spring due to the displacement of an element to displace a printing wire longitudinally. CONSTITUTION:When a signal according to printing data is outputted from a control circuit and a voltage is applied between electrodes of a piezoelectric element 5, the piezoelectric element 5 extends by a predetermined amount in its lamination direction. Then, a movable element 6 is pressed up, a plate spring 7 is bucklingly deformed, and an arm member 10 is inclinedly moved; in this manner, a printing wire 11 on the tip end of the arm member 10 is guided forwards by a guide member 14 to a printing position. When the plate spring 7 is bucklingly deformed, a maximum gradient is obtained at a point P which interiorly divides a full length L of the plate spring 7 in the ratio of approximately 1:3. Thus, the printing wire 11 mounted on the tip end of the arm member 10 extended from the point P can be statisfactorily advanced to the predetermined printing position. In addition, the plate spring 7 and the arm member 10 are made of a plate of nearly T-shape as an integral part.