Dot matrix printer using piezoelectric or other actuator having discharge control means.

摘要

A driver circuit for driving a piezoelectric element (P), including a charging circuit having a DC power source (E) and a coil (L) for charging the piezoelectric element, and a discharging circuit for discharging the piezoelectric element. When the piezoelectric element is charged, a first switching device (TR1) in the charging circuit is held on until a voltage of the element reaches a predetermined level below a line voltage of the power source. A second switching device (TR2) provided in the discharging circuit is turned on at the time when the first switching device is turned off or at a predetermined later time, and is turned off by the time when said first switching device is again turned on next activation of the piezoelectric element. A voltage limiter (D1, D2) inhibits the voltage of the piezoelectric element element from exceeding the predetermined level. The driver circuit may be used for a dot-matrix printer, which may be adapted to discharge the piezoelectric element for a comparatively long time where a distance between adjacent two dots to be formed is larger than a predetermined value. <IMAGE>