Patent ID: 7193756
Filing Date: 2007-03-20
Classification: B41J,H01L

Abstract:
1. A piezoelectric element comprising: a first electrode film; a piezoelectric layered film including a first piezoelectric film formed on the first electrode film and a second piezoelectric film formed on the first piezoelectric film and controlled in crystal orientation thereof by the first piezoelectric film; and a second electrode film formed on the second piezoelectric film, wherein each of the first and second piezoelectric films is an aggregate of columnar grains grown unidirectionally along the thickness direction of the piezoelectric layered film, wherein the first piezoelectric film has a smaller Pb content than a Pb content of the second piezoelectric film, wherein a columnar grain of the second piezoelectric film has a larger average cross-sectional diameter than an average cross-sectional diameter of a columnar grain of the first piezoelectric film, and wherein a ratio of a thickness of the piezoelectric layered film to the average cross-sectional diameter of the columnar grain of the second piezoelectric film is not less than 20 and not more than 60.