| 摘要 |
PURPOSE:To uniformize the particle size of ink drops, especially improving the quantity of uneven image by driving an ink drop jetting apparatus with a drive signal containing a plurality of frequency components equal in the threshold voltage and having a relationship of demultiply or multiplication therebetween. CONSTITUTION:For example, a unimorph type piezo-electric vibrator 2 with the diameter of D=10mm.phi in which a metal plate is glued on a piezo-electric ceramic plate is mounted at a long-diameter end of a horn-shaped pressure displacement chamber 3 so as to give the vibration diameter D'=8mm.phi. A diaphragm 4 with a thickness of delta=30mum is fastened at a short diameter end with an opening diameter of d=2mm.phi of a pressure displacement chamber 3 in such a manner as to be free to vibrate and mounted on an orifice plate 7 having an orifice 6 of 50mumphi made at the center with a fine gap of 400mum separated therefrom to form an ink chamber 5 with a thickness of DELTA=400mum. In an on-demand type ink drop jetting apparatus 1, when the frequency of the reference signal is set at 29kHz, frequency components of a drive signal are 20, 10, 20/3...20/nkHz, which makes the threshold value of respective frequencies equal to 110V thereby providing an ink drop of the same diameter. |
