| 摘要 |
<p>A method for ejecting a micro droplet having a diameter of 15ν or less without causing increase in the cost or size of an apparatus and deterioration in the reliability or the yield of manufacture. The waveform for driving a piezoelectric actuator comprises a first voltage variation process (31) for expanding a pressure generating chamber at falling time t1, a second voltage variation process (32) for contracting the pressure generating chamber abruptly at rising time t3 after holding the voltage for time t2, a third voltage variation process (33) for abruptly expanding the pressure generating chamber immediately after the second voltage variation process (32), and a fourth voltage variation process (34) for contracting the pressure generating chamber immediately after the third voltage variation process (33). The times t1 and t2 are set to satisfy the conditions shown below.</p> |
