Murata Manufacturing Co., Ltd.

Satoru Fujishima

Akira Ando

Hideharu Ieki

Takeshi Nakamura

Yukio Sakabe

Toshio Ogawa

Toshihiko Kittaka

Fumio Nakayama

Akira Kawabata

Fumio Takeda

Tadashi Shiosaki

A spherical piezoelectric speaker having a small and simple structure, a wide sound frequency range and a high sound pressure includes a spherical shell piezoelectric ceramic body which is hollow inside and an external electrode and an internal electrode defining a driving device for oscillating the spherical shell piezoelectric ceramic body. A sound absorber is provided in a hollow section of the piezoelectric ceramic body and a frame for holding the piezoelectric ceramic body is disposed on the outer surface of the piezoelectric ceramic body via dampers for reducing an influence of external oscillation.

Spherical piezoelectric speaker

An ultrasonic motor has a plurality of Langevin vibrators arranged in a ring, and the Langevin vibrators vibrate when an alternating voltage is provided thereto. Each of the Langevin vibrators has a first polarized region and a second polarized region which are polarized in mutually opposite directions. When the Langevin vibrators are supplied with an alternating voltage so as to vibrate in the length mode and flexural mode at substantially the same frequency, the edges of the metal terminals move in a elliptical motion, which drives the rotor.

Ultrasonic motor

An energy trapping type piezoelectric resonance device utilizing the mode of thickness extensional vibration comprises a plate-shaped body of a piezoelectric material and three or more electrodes provided to be opposed to each other through peizoelectric material layers in the direction of thickness of the body. At least one of the electrodes is provided to be smaller in area than the major surfaces of the body, to be capable of energy trapping.

Energy-trapping-type piezoelectric resonance device

A surface acoustic wave device comprising a surface acoustic wave substrate member composed by forming an aluminum oxide film and a thin zinc oxide film successively on a glass substrate. The thickness h.sub.1 of the aluminum oxide film and the thickness h.sub.2 of the zinc oxide film are set within ranges of 0.1.ltoreq.h.sub.1 /.lambda..ltoreq.10 and 0.05.ltoreq.h.sub.2 /.lambda..ltoreq.0.35 (where .lambda. is representative of wavelength of Sezawa wave) respectively, thereby to utilize Sezawa wave or a similar mode wave transmitted on the surface acoustic wave substrate member in multi-layer structure.

Surface acoustic wave device

Disclosed herein is a piezoelectric displacement element utilizing a sintered body obtained by stacking three or more ceramic layers (5a to 5h) through internal electrodes (6b to 6h) and co-firing the same. The sintered body has first, second and third regions when viewed in the direction of thickness. The first and third regions are so formed as to be displaced in reverse directions to each other. The second region consists of a plurality of piezoelectric ceramic layers (5d, 5e) in such a manner that an internal electrode (6e) interposed between the piezoelectric ceramic layers (5d, 5e) is connected with neither potentials in a driven state, whereby the second region is adapted not to be positively driven, to function as a buffer area.

Piezoelectric displacement element

A surface acoustic wave device comprising a surface acoustic wave substrate member composed by forming an aluminum nitride film and a thin zinc oxide film successively on a glass substrate. The thickness h.sub.1 of the aluminum nitride film and the thickness h.sub.2 of the zinc oxide film are set within ranges of 0.1.ltoreq.h.sub.1 /.lambda..ltoreq.10 and 0.05.ltoreq.h.sub.2 /.lambda..ltoreq.0.3 (where .lambda. is representative of wavelength of Sezawa wave) respectively, thereby to utilize Sezawa wave or a similar mode wave transmitted on the surface acoustic wave substrate member in multi-layer structure.

Sezawa surface acoustic wave device using a piezoelectric layer over a

A television tuner comprises a high frequency amplifier for receiving a high frequency signal received by an antenna, a local oscillator, and a mixer for mixing the high frequency signal from the high frequency amplifier and the oscillation frequency signal from the local oscillator for providing an intermediate frequency signal. The high frequency amplifier comprises a high frequency amplifying transistor, and a group of acoustic surface wave filter elements each exhibiting a high band pass characteristic corresponding to each of the television channels. The output of each filter in the filter group is transferred to the mixer through a corresponding switching device among a corresponding plurality of semconductor switching devices individually coupled between the corresponding output terminals of the filters and the ground by turning off the semiconductor switching device corresponding to a desired channel and turning on the remaining switching devices. These semiconductor switching devices are adapted to be on/off controlled individually in response to corresponding flip-flops adapted to be selectively set in response to a channel selection switch. The local oscillator comprises another group of acoustic surface wave resonators each exhibiting a resonance characteristic corresponding to a channel and a feedback loop. The respective resonators are selectively enabled or disabled by means of a corresponding plurality of semiconductor switching devices in the same manner as done in the above described filters.

Television tuner

A piezoelectric tuning fork device comprises a plate-like tuning vibrator having a pair of prongs and a base with a slot defined between the prongs. The tuning vibrator has at least one electrode layer deposited on and overlying a piezoelectric layer formed on one of the opposed major surfaces of the tuning vibrator. The electrode layer is generally U-shaped and has a pair of opposed leg portions each so positioned as to have its longitudinal axis located to one side of the imaginary corresponding prong.

Growing community of inventors

Muko, Japan

Satoru Fujishima