METHOD OF DRIVING INK JET RECORDING HEAD

摘要

A piezoelectric element-driving circuit 50 generates a driving signal including two pulses in one recording period. A time period between an end of the first pulse and a start of a first signal T21 of the second pulse is set approximately equal to (a recovery time TR of an ink interface (meniscus) at the end of an ink conduit) + (3/8 a period Tm of a natural vibration). This arrangement enables an ink droplet to be spouted while the meniscus is hardly concaved inward the ink conduit. This accordingly increases the total weight of the ink droplet by approximately 30% at the maximum, compared with the sum of the ink weights when the first pulse and the second pulse are output separately. Another preferable application determines the time difference between the timing of spouting the first ink droplet and the timing of spouting the second ink droplet by taking into account a period Tc of a Helmholtz resonance of the meniscus. This arrangement enables the variable range of the ink weight spouted in one recording period to be extended when the piezoelectric element is regulated to vary the amount of ink spouted from each nozzle. <IMAGE>