Abstract: A piezoelectric vibrator uses aluminum nitride as piezoelectric material and thickness sliding vibration as the primary vibration. A polarization direction of the primary vibration is along the longitudinal direction of its vibrating element. This vibrator eliminates undesired resonance, caused by a width of the vibrating element, from a vicinity of a resonance frequency of the primary vibration. Vibrating element 1 has width W and thickness H defined as follows: 2.0≦W/H≦4.0 or 4.3≦W/H≦5.7 or 6.2≦W/H≦7.8 or 8.2≦W/H≦9.8.

Abstract: A method for manufacturing a bimorph type piezoelectric element including a first step of providing a first piezoelectric single-crystal plate having a first surface and a second surface; a second step of providing a second piezoelectric single-crystal plate having a third surface and a fourth surface; a third step of directly bonding the third surface of the second piezoelectric single-crystal plate to the first surface of the first piezoelectric single-crystal plate without using any adhesives; a fourth step of forming a freely vibrating part by grinding away the second surface of the first piezoelectric single-crystal plate to a first depth and with a first spacing; and a fifth step of producing an element having a supporting member and the freely vibrating part by cutting the first piezoelectric single-crystal plate and second piezoelectric single-crystal plate with the freely vibrating part included, which have been prepared in the fourth step, with a predetermined spacing and at least in one of the dire

Abstract: A piezoelectric vibration element comprises a vibration element part 1, a vibration propagation part 2 made of a same material with a greater thickness than the vibration element part 1, a groove 6 disposed in the boundary of the vibration element part 1 and vibration propagation part 2, excitation electrodes 3 confronting the face side and back side of the vibration element part 1, a connection electrode 4 disposed in the vibration propagation part 2, and an external lead-out electrode 5 connected electrically to the connection electrode 4. In this piezoelectric vibration element, the main vibration is the overtone mode, that is, when the lowest order wave mode is first-order or second-order, the wavelength in the thickness direction is (2n+1) times (n being a natural number) thereof.

Abstract: The present invention relates to a bimorph type piezoelectric acceleration sensor used in detecting vibrations of a variety of equipment such as a hard disk, CD-ROM and the like and has the objective of providing a bimorph type piezoelectric element for acceleration sensor of a small size, high sensitivity, a narrow range of sensitivity variation and a low cost by forming a freely vibrating part and a supporting means at the same time in single-piece construction through a grinding away process applied to lithium niobate. One section of a structure formed of two of a lithium niobate single-crystal plate directly bonded together with the polarization directions thereof reversed each other is applied with a grinding away process to produce a freely vibrating part (32a) and the remaining section, where no grinding away process has been applied, serves as a supporting member (33a), thus both being formed simultaneously and made integral with each other, and electrodes (31a, 31b) are formed by electroless plating.

Abstract: The present invention relates to a bimorph type piezoelectric acceleration sensor used in detecting vibrations of a variety of equipment such as a hard disk, CD-ROM and the like and has the objective of providing a bimorph type piezoelectric element for acceleration sensor of a small size, high sensitivity, a narrow range of sensitivity variation and a low cost by forming a freely vibrating part and a supporting means at the same time in single-piece construction through a grinding away process applied to lithium niobate. One section of a structure formed of two of a lithium niobate single-crystal plate directly bonded together with the polarization directions thereof reversed each other is applied with a grinding away process to produce a freely vibrating part (32a) and the remaining section, where no grinding away process has been applied, serves as a supporting member (33a), thus both being formed simultaneously and made integral with each other, and electrodes (31a, 31b) are formed by electroless plating.

Abstract: A piezoelectric vibrator using thickness mode as the primary vibration and having a cross section of a bevel or convex configuration is provided which is superior in mechanical strength, easy to steadily mount, and has a small dispersion of characteristic. By employing a structure in which a vibrator 1 and a support section 2 are composed of the same material, the end portions of the vibrator section are integrated with the support section on the periphery of the vibrator, and the configuration of the cross section of the vibrator 1 is such that the thicknesses of the end portions of the vibrator are smaller than that of the central portion of the vibrator, a superior mechanical strength without chipping or cracking at the end portions of the vibrator is obtained allowing easy mounting while keeping the vibrator size small.