Abstract: A piezoelectric sintered ceramic made of (a) 100 parts by weight of main components having a composition represented by the general formula: (Pb1−yMy)(ZrzTi1−z)O3, wherein M is at least one element selected from the group consisting of Sr, Ba and Ca, and y and z are numbers satisfying 0.01≦y≦0.10, and 0.51≦z≦0.56, respectively; (b) 0.05-1.0 parts by weight, as Fe2O3, of Fe; and (c) 10-1000 ppm of Ag.

Abstract: Disclosed is a piezoelectric loudspeaker.According to the present invention, a piezoelectric loudspeaker comprises: a flat compound piezoelectric sheet in which multiple piezoelectric devices are arranged in an organic material; electrodes which are provided on respective surfaces of the compound piezoelectric sheet; an acoustic impedance matching support layer for maintaining the flat compound piezoelectric sheet in a curved shape and for matching an acoustic impedance; and a support frame for supporting the compound piezoelectric sheet at its circumference. Thus, sound reproduction with a desirable frequency properties that have little distortion can be performed.

Abstract: A flow rate control valve including a valve chest having an open end, an inflow passage and outflow passage each having one end communicating with the valve chest and the other end opened, a valve seat provided at the end of the inflow passage or outflow passage communicating with the valve chest, a sheet-like diaphragm provided to tightly close the open end of the valve chest and a stacked-type dispalcement device made of an electromechanical transducing material exhibiting the maximum value of piezoelectric distortion constant at a higher temperature range than 100.degree. C. or above and which exerts a pressure on the diaphragm by its deformation to change the position of the diaphragm, thereby controlling the gap between the valve seat and the diaphragm.

Abstract: In an overall stacked piezoelectric element, the material for the electrode was selected from aluminum, nickel and copper each alone or alloys based on aluminum, nickel or copper, and further the parts of the electrodes which contact with molding resin on the side face of the stacked body and the parts which have to be insulated from the lead-out terminals were subjected to an oxidation or nitriding treatment. As the result, an improved element was obtained which is of a high reliability, suited to low voltage operation and suffers no short-circuit of the electrodes even when water permeates to the side face of the stacked body during operation in a humid atmosphere.

Abstract: In an overall stacked piezoelectric element, the material for the electrode was selected from aluminum, nickel and copper each alone or alloys based on aluminum, nickel or copper, and further the parts of the electrode which contact with molding resin on the side face of the stacked body and the parts which have to be insulated from the lead-out terminals were subjected to an oxidation or nitriding treatment. As the result, an improved element was obtained which is of a high reliability, suited to low voltage operation and suffers no short-circuit of the electrode even when water permeates to the side face of the stacked body during operation in humid atmosphere.

Abstract: A laminated displacement device comprises: a laminate which is formed by alternately laminating thin plates made of an electromechanical converting material and internal electrodes made of a conductive material; and external electrodes which are provided in the side portions of the laminate and are connected to the internal electrodes. In the laminated displacement device, a plane projection area which is obtained by overlapping the internal electrodes in the laminating direction is set to be smaller than a plane projection area which is obtained by overlapping the thin plates in the laminating direction. A relation of B/A.gtoreq.0.5 is satisfied between the width dimension A of a displacement portion which is formed by overlapping the projections of the internal electrodes in the laminating direction and the width dimension B of a non-displacement portion which is formed between the edge of the displacement portion and the side surface of the laminate.

Abstract: A laminate displacement device comprises a laminate body having a plurality of thin plates made of an electromechanical converting material and a plurality of internal electrodes made of conductive material superposed on each other. The internal electrodes are used for every other electrode alternately as electrodes of first and second conductivity type, respectively. A first insulating layer is formed on one side surface of the laminate body so that the internal electrodes used for the electrodes of first conductivity type are exposed. Further a second insulating layer is formed on another side surface of the laminate body so that the internal electrodes used for the electrodes of second conductivity type are exposed. A pair of external electrodes are formed on the first and second insulating layers, which bridge the internal electrodes used as the electrodes of first and second conductivity type, respectively.

Abstract: A flow rate control valve including a valve chest having an open end, an inflow passage and outflow passage each having one end communicating with the valve chest and the other end opened, a valve seat provided at the end of the inflow passage or outflow passage communicating with the valve chest, a sheet-like diaphragm provided to tightly close the open end of the valve chest and a stacked-type displacement device made of an electromechanical transducing material exhibiting the maximum value of piezoelectric distortion constant at a higher temperature range than 100.degree. C. or above and which exerts a pressure on the diaphragm by its deformation to change the position of the diaphragm, thereby controlling the gap between the valve seat and the diaphragm.

Abstract: A laminate-type displacement element comprising a plurality of thin plates made of an electromechanical conversion material laminated alternately with internal electrodes which cover substantial portions of said thin plates to form a laminate; a pair of external electrodes connected to said internal electrodes on both sides of said laminate; and a buffer portion extending between a non-deflecting portion located in the vicinity of each side surface of said laminate and a deflecting portion located within said laminate, said buffer portion having a deflection amount which increases gradually from 0% at a position adjacent to the non-deflecting portion to 100% at a position adjacent to the deflecting portion.