Ink jet printing apparatus with controlled compression and ejection of colorants in liquid ink

An ink jet printing apparatus, comprising:

• a head substrate having an electrode array formed on a surface of the head substrate over which ink having colorants distributed in a solvent is supplied;
• voltage application means for applying voltages to the electrode array to produce an electric field for exerting an electrostatic force on the colorants in the ink supplied over the electrode array such that the colorants are compressed and ejected from a colorant ejection point on the electrode array toward a recording medium;
• an auxiliary substrate provided over the head substrate defining an ink supply passage through which the ink is supplied over the electrode array;
• and
• colorant convey means, provided on a surface of the auxiliary substrate facing toward the electrode array, for conveying colorants in the ink through the ink supply passage toward the colorant ejection point on the electrode array.

An ink jet printing apparatus, comprising:

• a head substrate;
• at least one electrode formed on a surface of the head substrate;
• an ink supply unit configured to supply ink in which colorants are distributed in a solvent, the ink being provided over a top surface of the at least one electrode by positive pressure applied to the ink by the ink supply unit, and the ink being provided over a tip portion and a bottom surface of the at least one electrode by negative pressure applied to the ink by the ink supply unit;
• and
• a voltage application unit connected to the at least one electrode and configured to provide an apply voltage to the at least one electrode to produce an electric field for exerting an electrostatic force on the colorants in the ink provided over the at least one electrode by the ink supply unit such that the colorants are compressed and ejected toward a recording medium.