摘要 |
<p>The shuttle print head (10) of a matrix printer carries a plurality of printing elements (12) and is supported by leaf springs (28, 30) on the printer frame (32). The print head is fixed to the movable core (18) of a linear electric motor (20) whose driving coil (22) is also supported on the frame by leaf springs (34, 36). The masses of the print head array and coil are made equal to form a balanced mass/spring system having a natural resonant frequency of oscillation of sinusoidal motion. The resonant frequency is chosen to correspond to a desired print rate. The drive coil is energized with alternating current at the resonant frequency in order to maintain the sinusoidal oscillation of the print head array at the required amplitude of oscillation. Selective energization of the printing elements effects selective printing of indicia at equal space column locations. </p> |