| 摘要 |
PURPOSE:To prevent the electrolysis of an ink, by providing one electrode composed of specific metal oxide having conductivity, heat resistance and oxidation resistance with specified values to the entire inner surfaces of a plurality of ink cavities formed to the surface of a piezoelectric plate. CONSTITUTION:Ink cavities 11 are provided to a piezoelectric plate 10 composed of piezoelectric ceramics in parallel and each of them has such a cross-section that narrow grooves are further deeply bored along both side surfaces of a U-shaped groove. One electrode 16 is provided to the entire inner surface of each ink cavity 11 and the other electrode 17 is provided to the part of the under surface of the piezoelectric plate 10 opposed to the extensible and contractable part 18 being the protruding part at the central part of said cavity. When driving pulse voltage is applied between the electrodes 16, 17, the extensible and the contractable part 18 composed of a piezoelectric material is compressed in the longitudinal direction and extended in the lateral direction and, as a result, the inner volume of the ink cavity expands as a whole and the ink cavity 11 sucks in ink 1 from an ink common supply chamber 14. Contrarily, when pulse voltage becomes zero, the ink 1 is formed into an ink droplet to be injected from a nozzle 12. The material quality of the electrode 16 is selected from tin oxide, indium oxide and indium oxide-tin oxide composite oxide. |
