Patent ID: 6908177

Claim:
An electrostatic ejection type ink jet head that uses ink containing a charged fine particle component, controls ejection/non-ejection of the ink by means of an electrostatic force by applying a predetermined voltage to individual electrodes in accordance with image data, and records an image corresponding to the image data on a recording medium, the electrostatic ejection type ink jet head comprising: a head substrate; first drive electrodes provided for each of the individual electrodes; a second drive electrode provided commonly among all of the individual electrodes; ink guides arranged on the head substrate for each of the individual electrodes; and an insulating substrate in which through holes are established for each of the individual electrodes at a position corresponding to an arrangement of the ink guides, wherein the head substrate and the insulating substrate are arranged with a predetermined space therebetween, a flow path of the ink is formed between the head substrate and the insulating substrate, the ink guides are passed through the through holes established in the insulating substrate, tip portion of the ink guides are protruded above a surface of the insulating substrate on a recording medium side, the first drive electrodes are arranged closer to the insulating substrate side than the flow path of the ink, and the second drive electrode is arranged closer to the head substrate side than the first drive electrodes, and at the time of recording of the image, ejection/non-ejection of the ink is controlled by biasing the second drive electrode to a predetermined voltage level having the same polarity as the fine particle component contained in the ink and switching the first drive electrodes between a high-impedance state and a ground level in accordance with the image data.