| 摘要 |
PROBLEM TO BE SOLVED: To obtain a high speed recording apparatus low in cost, high in reliability and having many nozzles in high density, that is small in size. SOLUTION: A pressure chamber 1a is surrounded on both sides thereof by side walls 2a, 2b each composed of a piezoelectric element and the upper, lower and front sides thereof are surrounded by a top plate 3, an under plate 4 and a nozzle plate 5. The upper and rear surfaces of the side walls 2a, 2b have electrodes 8a, 8b and electrodes 9a, 9b and these electrodes are electrically connected to a drive circuit. The parts exposed to the interior of the pressure chamber 1a of the electrodes 8a, 8b, 9a, 9b are covered with a protective film to prevent the direct contact of ink with the electrodes. The side walls 2a, 2b are polarized in the height direction (show by an arrow P). At a time of driving, voltage is applied in the same direction as polarization to expand the vol. of the pressure chamber and, thereafter, voltage is returned to the original voltage to pressurize the ink in the pressure chamber to emit ink droplets. |
