Ink-jet printer using RF tone burst drive signal

摘要

A driving circuit controls a time for applying a drive signal to a piezoelectric element so as to bring a control in the number of ink droplets squirted from a liquid surface of liquid ink according to a gray scale level of an image to be printed on a printed object. According to application of the drive signal, acoustic waves emitted from a piezoelectric element array are focused in a main scanning direction, made incident to an acoustic lens via an acoustic matching layer, further focused in a direction orthogonal to the main scanning direction and focused in a vicinity of the liquid surface in a point form. In the vicinity of the liquid surface, an ink liquid mound is formed by means of pressure (discharging pressure) generated by the focused acoustic waves and then from a tip of the ink liquid mound an ink droplet according to the application time is squirted. The squirted ink droplet is ejected and stuck to the printed object. By performing main and subscanning to the printed object, a two-dimensional image is printed thereon.