| 摘要 |
PURPOSE:To improve quality of printed letter, by varying excitation voltage to be impressed onto a ultrasonic wave oscillator of an ink jet head on the basis of signal selected in accordance with kind of image. CONSTITUTION:Ink in an ink tank 4 is sent into an ink chamber of an ink jet head 1 by the liquid level, capillarity or weak pressure, and while this ink chamber is usually filled with the ink, the surface tension prevents the ink from being jetted out of an orifice 3. Once a letter-printing signal has been impressed on an oscillator driving circuit 5, however, a ultrasonic wave oscillator 2 displaces to rapidly decrease volume of the ink chamber, jet out the ink jet particles from the orifice 3 and cause letter to be printed on a recording paper 6. A triplet- or quartet switch 10 is provided for selection of kind of image, so that oscillation voltage of the ultrasonic wave oscillator 2 is changed by the pressed position of the switch. |
