Abstract: A piezoelectric resonator includes a base member including a plurality of laminated piezoelectric layers and internal electrodes. The adjacent piezoelectric layers are polarized in different directions with an internal electrode disposed therebetween. A groove is provided on one lateral surface of the base member, and every other internal electrode is exposed at both sides of the groove. Insulating films are disposed on unexposed portions of the internal electrodes. External electrodes are provided on both sides of the groove in the base member and are connected to the internal electrodes. As a result of this structure, the piezoelectric resonator prevents a reduction in the difference .DELTA.F between the resonant frequency and the anti-resonant frequency.

Abstract: A piezoelectric resonator having a small spurious resonance and a large difference .DELTA.F between the resonant frequency and the antiresonant frequency has a compact size and an external electrode has a structure which prevents damage or breaking of the external electrode. The piezoelectric resonator has a substantially rectangular-parallelepiped base member which includes a plurality of laminated piezoelectric layers. A middle portion of the piezoelectric layers is polarized in opposite directions relative to each other. On main surfaces of the middle part of the piezoelectric layers, first and second groups of inner electrodes and are exposed alternately at both side surfaces of the base member. On both side surfaces of the base member, first and second external electrodes are arranged so as to alternately connect to the first and second groups of inner electrodes.

Abstract: A piezoelectric resonator which vibrates in a longitudinal vibration mode includes first insulating films disposed on a side surface of a base member so as to cover at least part of exposed portions of a first group of the internal electrodes and second insulating films disposed on the side surface of the base member so as to cover at least part of the exposed portions of a second group of the internal electrodes. A first thin-film external electrode extends continuously in the longitudinal direction of the base member on the first insulating films and a second thin-film external electrode extends continuously in the longitudinal direction of the base member on the second insulating film. A first conductive resin film and a second conductive resin film are respectively provided on the first thin-film external electrode and the second thin-film external electrode such that even if the thin-film external electrodes are broken or damaged, the piezoelectric resonator still functions.

Abstract: A piezoelectric sensor has a piezoelectric element having a specific axis of sensitivity and a package for the piezoelectric element. The package has a rectangular parrallelopiped configuration with opposite longitudinal end surfaces having a height-to-width ratio of about 1:1. External lead electrodes are formed to cover at least the longitudinal end surfaces. A method and apparatus for detecting if the sensor is disposed in the proper posture is also disclosed.

Abstract: A piezoelectric component achieves a desired Qm by using a presently available piezoelectric material. The piezoelectric component includes a supporting substrate on which pattern electrodes are provided. Electroconductive supporting members are disposed on the pattern electrodes, and a piezoelectric resonator is mounted on the supporting members. External electrodes of the piezoelectric resonator and the pattern electrodes are electrically connected to each other by the supporting members. Gaps between the piezoelectric resonator and the supporting substrate are filled with a first elastic material element. A second material element may be provided on the surface of the piezoelectric resonator disposed opposite to the surface of the resonator facing the supporting substrate. Only one of these elastic material elements or both these elastic material elements may be used.

Abstract: In a piezoelectric element (21), an internal electrode (31) is embedded in a piezoelectric ceramic body (22) to extend in its longitudinal direction, first to third surface electrodes (23 to 25, 27 to 29) are formed on upper and lower surfaces of the piezoelectric ceramic body (22) in first to third portions along the longitudinal direction, connecting electrodes (26, 30) are formed to connect the first to third surface electrodes (23 to 25, 27 to 29) with each other, the first to third portions are so polarized that the second portion is oppositely polarized to the first to third portions, and regions located above and under the internal electrode are polarized in opposite directions in the respective ones of the first to third portions.

Abstract: A piezoelectric resonator having a small spurious resonance, a large frequency difference .DELTA.F between the resonant frequency and the anti-resonant frequency, adjustable capacitance, and high design flexibility includes a base member formed by laminating, for example, a plurality of piezoelectric layers and internal electrodes. When the length, width, and thickness of the base member are indicated by L, W and T, respectively, the dimensions of the member are selected to satisfy the conditions of L.gtoreq.2W and L.gtoreq.2T. The base member is polarized at both ends of each internal electrode in opposite directions. A groove is preferably formed on one lateral surface of the base member, and at both sides of the groove, the internal electrodes are alternately covered with two insulating films. The two insulating films are respectively formed to cover the different internal electrodes. External electrodes are formed on both sides of the groove of the base member and are connected to the internal electrodes.

Abstract: A ladder filter has a piezoelectric resonator having reduced spurious vibrations and having a wider range of selection of the difference .DELTA.F between the resonant frequency and the antiresonant frequency, and has a substantially reduced size. The ladder filter includes an insulating substrate on which four pattern electrodes are provided. Four lands are respectively formed as portions of the four pattern electrodes. Another land is formed as a portion of the second pattern electrode. External electrodes of four piezoelectric resonators adapted to vibrate in a longitudinal vibration mode and capable of being mounted in a surface mount manner are connected to the land of the pattern electrodes by supporting members made of an electroconductive material. The four piezoelectric resonators are arranged in a row in the order of a first series resonator, a first parallel resonator, a second parallel resonator and a second series resonator.

Abstract: A piezoelectric resonator includes a base member having a piezoelectric member at the center and dielectric members disposed at opposite ends. A plurality of internal electrodes are provided in the base member. The piezoelectric member layer at the center of the base member is polarized in the longitudinal direction of the base member in opposite directions at both sides of each internal electrode. The center section of the base member is used as a vibrating section. On the other hand, the dielectric members at both ends of the base member are not polarized and are used as capacitor sections. Adjacent internal electrodes are connected to external electrodes serving as input and output electrodes, respectively.

Abstract: A piezoelectric resonator has a base member including a plurality of piezoelectric layers laminated with electrodes disposed therebetween. A first vibrating section is formed so as to occupy most of the base member. In the first vibrating section, adjacent piezoelectric layers sandwiching one electrode therebetween are polarized in opposite directions in the longitudinal direction of the base member. At both sides of the first vibrating section, second vibrating sections are formed. A piezoelectric layer of each of the second vibrating sections is polarized in the same direction as an adjacent piezoelectric layer in the first vibrating section with an electrode disposed therebetween. An electric field is applied in opposite directions to adjacent piezoelectric layers disposed on both sides of an electrode in the base member.

Abstract: A piezoelectric resonator has a base member including laminated piezoelectric layers and internal electrodes. The base member is polarized in different directions at both sides of each internal electrode. The internal electrodes are alternately covered by insulating film on opposing side surfaces of the base member. External electrodes are formed on the opposing side surfaces of the base member and the internal electrodes are connected thereto, respectively. At both ends of the base member, inactive sections are formed such that an electric field is not applied to the base member by covering consecutive plural electrodes with the insulating film. The center of the base member serves as an active section since an electric field is applied.

Abstract: A piezoelectric component has a substantially stronger connection between a substrate and a piezoelectric resonator and has improved electrical reliability. The piezoelectric resonator includes an insulating substrate having pattern electrodes disposed therein. A piezoelectric resonator capable of vibrating, for example in a longitudinal vibration mode is mounted on the substrate. A supporting member prepared separately as a pre-formed material member is bonded to the piezoelectric resonator at a nodal point of the resonator. A first flat surface of the supporting member is bonded to a vibrating electrode on the piezoelectric resonator by a first bonding and supporting material while a second flat surface of the supporting member is bonded to one of the pattern electrodes on the substrate by a second bonding and supporting material.

Abstract: A piezoelectric element includes an internal electrode embedded in a piezoelectric ceramic body so as to extend in a longitudinal direction of the body. First to third surface electrodes are formed on upper and lower surfaces of the piezoelectric ceramic body in respective first to third portions along the longitudinal direction. Connecting electrodes are formed to connect the first to third surface electrodes with each other. The first to third portions are polarized so that the second portion is polarized opposite to the polarization of the first and third portions, and regions located above and below the internal electrode are polarized in opposite directions in the respective ones of the first to third portions.

Abstract: A piezoelectric resonator has a substantially rectangular-parallelpiped-shaped base member. The base member includes laminated piezoelectric layers which are polarized in the longitudinal direction of the base member such that the directions of polarization differ at adjacent piezoelectric layers. Internal electrodes are disposed between the piezoelectric layers. The internal electrodes each preferably comprise a plurality stripes dispose on main surfaces of the piezoelectric layers. On opposing side surfaces of the base member, the internal electrodes are alternately covered by at least two insulating films. The at least two insulating films cover different internal electrodes. External electrodes are disposed on the opposing side surfaces of the base member and are connected to internal electrodes.

Abstract: A piezoelectric resonator has a substantially rectangular-parallelpiped-shaped base member. The base member includes a plurality of laminated piezoelectric layers. The piezoelectric layers are polarized in the longitudinal direction of the base member such that the direction of polarization differs at adjacent piezoelectric layers. At opposite major surfaces of the plurality of piezoelectric layers, internal electrodes are disposed. The internal electrodes have surface areas with different sizes and therefore, areas of pairs of opposing electrodes have different sizes. The internal electrodes are alternately covered by at least two insulating films provided on opposing side surfaces of the base member. The at least two insulating films cover different internal electrodes. External electrodes are disposed on the same or the opposing side surfaces of the base member and the external electrodes are connected to the internal electrodes.

Abstract: A piezoelectric resonator has a base member formed by laminating a plurality of piezoelectric layers and electrodes. The base member is polarized in different directions at both sides of each electrode. Electrodes are alternately covered by a first insulating film and a second insulating film, respectively, at both sides of a groove formed in the base member. The first insulating film covers electrodes which are not covered by the second insulating film, and vice versa. External electrodes are formed at both sides of the groove on the base member and the internal electrodes are connected to the external electrodes. A support member made from an electrically conductive material is provided at the approximate centers of the external electrodes.

Abstract: A piezoelectric resonator has a substantially rectangular-parallelpiped-shaped base member including a plurality of laminated piezoelectric layers. The piezoelectric layers have different dimensions in the longitudinal direction of the base member. The piezoelectric layers are polarized in the longitudinal direction of the base member such that the direction of polarization differs at every other piezoelectric layer. At both surfaces of the piezoelectric layers, a plurality of internal electrodes are disposed. The internal electrodes are alternately covered by at least two insulating films disposed on opposing side surfaces of the base member such that the at least two insulating films cover different electrodes. External electrodes are provided on the opposing side surfaces of the base member and the external electrodes are connected to internal electrodes.

Abstract: A ladder type filter achieves a substantial reduction in distortion in filtering characteristics. The ladder type filter includes a supporting substrate formed of an insulating material. Supporting members are attached to lands which are formed by portions of pattern electrodes disposed on the supporting substrate. A plurality of piezoelectric resonators are mounted on the supporting members and connected in a ladder arrangement to define a ladder type filter. Each piezoelectric resonator has a base member in which piezoelectric layers and internal electrodes are laminated. External electrodes formed on one side surface of the base member are connected to the internal electrodes disposed in the base member. The width w and the thickness t of the piezoelectric resonators and the number n of laminated layers each comprising one of the piezoelectric layers and one of the internal electrodes disposed adjacent to the corresponding piezoelectric layer are selected so as to satisfy 1.ltoreq.log.sub.10 (n.sup.2 wt).

Abstract: To provide a mounting arrangement of acceleration detecting elements capable of detecting acceleration over a wide range with as few elements as possible and having substantially the same detection sensitivity with regard to acceleration operating in any direction of orthogonal coordinate axes, two acceleration detecting elements are disposed on an element attaching surface defining x-y plane in an x-y-z orthogonal coordinate system, such that orientations of the two acceleration detecting elements are along the x axis and y axis on the element attaching surface, a maximum sensitivity direction of one of the two acceleration detecting elements being inclined from the y axis toward the z axis by 40.degree. to 50.degree. and a maximum sensitivity direction of the other of the acceleration detecting elements being inclined from the x axis to the z axis by 40.degree.to 50.degree..

Abstract: An acceleration sensor includes a sensor body obtained by forming first and second signal electrodes on outer major surfaces of first and second piezoelectric ceramic plates which are pasted to each other through an intermediate electrode. The sensor body is formed to be mechanically supported in the form of a center beam, and has first to third regions formed so that stress is caused in different directions in adjacent ones of the first to third regions upon acceleration. The first and second piezoelectric ceramic plates are polarized in opposite directions in the second region so that charges which are opposite in polarity to charges generated in the second region are not drawn from the signal electrodes in the first and third regions.