Kyocera Corporation

Gen Shimura

Takeshi Hirayama

Shuhei Tabata

Makoto Higashibeppu

Yukihiro Hasegawa

Atsushi Ishihara

Takashi Miyahara

In a piezoelectric ceramic composition including potassium sodium niobate, a transition temperature at which a phase transition between an orthorhombic crystal structure and a tetragonal crystal structure occurs lies in a temperature range of −20° C. or higher and 60° C. or lower. In the piezoelectric ceramic composition, αt/αo is 0.72 or more, where αo represents a coefficient of linear expansion determined when a crystal structure is orthorhombic in the temperature range, and αt represents a coefficient of linear expansion determined when a crystal structure is tetragonal in the temperature range.

Piezoelectric ceramic composition and piezoelectric actuator

A first active region is made of a piezoelectric overlaps a midsection of a pressure chamber when viewed in plan through a pressure applying surface. A second active region is made of a piezoelectric member closer than the first active region to the pressure applying surface. The second active region extends over both a peripheral section of the pressure chamber and an outer region located outside the pressure chamber when viewed in plan through the pressure applying surface. A driver controls intensity of a first electric field applied to the first active region and intensity of a second electric field applied to the second active region such that the time period over which the first active region contracts and the time period over which the second active region contracts overlap or coincide with each other. The first electric field is more intense than the second electric field.

Liquid ejection head and recording apparatus

A piezoelectric ceramic composition is represented by a composition formula ABOand includes potassium sodium niobate containing K and Na that account for 80% or more of an amount of A-site elements and containing Nb that accounts for 70% or more of an amount of B-site elements. The piezoelectric ceramic composition contains Ta and Fe at a B-site.

Piezoelectric ceramic composition

A piezoelectric actuator includes a common electrode on a piezoelectric layer at a first side adjacent to a first surface and extends over a plurality of piezoelectric elements. A plurality of first individual electrodes is on the piezoelectric layer at a second side adjacent to a second surface. Each of the plurality of first individual electrodes is at a piezoelectric element of the plurality of piezoelectric elements, and are not electrically connected together. A first insulating layer is on the common electrode at the first side and extends over the plurality of piezoelectric elements. A plurality of second individual electrodes is on the first insulating layer at the first side. Each of the plurality of second individual electrodes is at a piezoelectric element of the plurality of piezoelectric elements, and overlap centers of the plurality of first individual electrodes. The plurality of second individual electrodes are electrically connected together.

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Kirishima, Japan

Gen Shimura