| 摘要 |
PROBLEM TO BE SOLVED: To perform gradation printing by making the ink emitting amt. from an ink chamber variable by simple control. SOLUTION: A reference voltage waveform of a triangle wave is outputted from a power supply circuit 12 to be applied to a piezoelectric member 11i. The transistor 13i corresponding to the piezoelectric member desired to be driven is subjected to ONoperation simultaneously with the application of the reference voltage waveform to the piezoelectric member. By this constitution, an ink chamber is opened. Thereafter, immediately before the reference voltage waveform falls to earth potential steeply, the transistor is once subjected to OFF-operation. By this mechanism, the piezoelectric member holds charge to hold its displacing position. At this time, the supply of ink to the ink chamber is performed. After the elpse of a proper holding time, the transistor is again subjected to ON-operation to return the piezoelectric member to a steady state. By this constitution, the ink chamber returns to the original state suddenly and ink is emitted from the ink chamber. The ink emitting amt. at this time is made variable by making the holding time variable and gradation printing can be performed. |
