Circuit for driving piezo-element in ink printer - has drive circuits for each piezo-element, potential divider inputs, additional DC voltage preventing depolarisation

摘要

A circuit for driving piezoelements in an ink printer has a drive circuit (ASS1-ASSn) for each piezoelement (CP1-CPn) with an ohmic potential divider input. The divider ends can be switched between low and high voltage and to earth respectively. Its tapping can be switched either to the piezoelement's control connection via a coupling capacitor or to the earth switch. An additional d.c. voltage (UO) is applied in the polarisation direction to the line connecting the capacitor and control input via a resistor (R31-R3n) which is large compared to the divider resistors (R11-R1n, R21-R2n). USE/ADVANTAGE - The circuit helps to eliminate depolarisation of low-cost, effective piezoelements.