Ngk Spark Plug Company, Limited

Yasufuku Ceramics Co., Ltd.

Marusu Glaze Co., Ltd.

Tsutomu Tsunooka

Takashi Yamamoto

Shigeo Saito

Hiroshi Ito

Hirofumi Ozeki

Kanji Ohya

Shogo Kawajiri

Tadashi Takeuchi

Koji Ogura

Kunihiro Ushida

Takeo Kinoshita

Hitoshi Ohsato

Tomonori Sugiyama

Hideyuki Ikoma

A sintering temperature can be lowered to 1,200&#xb0; C. by adding from 15% by weight or more to 35% by weight or less of rutile-type titanium dioxide into forsterite. By carrying out sintering at such a low temperature, a sintered product can be obtained in which sintering was carried out while retaining the respective crystal phases of the forsterite and rutile-type titanium dioxide. Such a sintered product is an excellent high-frequency ceramic composition, wherein the high quality factor Q&#xb7;f value derived from forsterite is hardly impaired, and, the absolute value of the temperature coefficient &#x3c4;is controlled to 30 ppm/&#xb0; C. or less by rutile-type titanium dioxide.

High-frequency porcelain composition, process for producing the same and planar high-frequency circuit

A piezoelectric composite material prepared by compounding a ferroelectric ceramic powder comprising microcrystals having virtually single domains and a polymer. This composite has both the high piezoelectric property of the ferroelectric ceramic and the pliability of the polymer.

Piezoelectric composite material

A particulate lead titanate ceramic obtained by calcining a mixture containing TiO.sub.2 and PbO at 1150.degree.-1300.degree. C., the proportion of the PbO being greater than 1 mole per mole of the TiO.sub.2. A composite material having the particulate lead titanate ceramic supported in an organic substrate exhibits improved piezoelectric properties and is useful as a piezoelectric element or pyroelectric element.

Particulate lead titanate ceramic and composite material containing same

A dielectric ceramic composition is disclosed, comprising as three components lead nickel niobate, lead titanate, and lead magnesium iron tungstate, wherein the composition in terms of the three components is represented by the formula

Dielectric ceramic composition and process for producing the same

A piezoelectric composite material having excellent piezoelectric property and workability, which is prepared by compounding in a specific mixing ratio a ferroelectric ceramic powder comprising microcrystals having uniform size and virtually a single domain and a polymer. The ceramic powder is obtained by preparing a ceramic having a desired composition by causing the appropriate mixture of starting powders to undergo a solid phase reaction, grinding the reaction product, annealing the resulting powder under heat and optionally chemically etching it.

Sheet-like piezoelectric element in which a plurality of slits are formed between the comb-shaped electrodes alternately projected in a zigzag shape from a pair of terminals arranged oppositely, a piezoelectric layer of composite piezoelectric material is filled into the slits, a DC voltage is applied between the terminals to polarize the adjacent layers in reverse directions to each other, and the electrodes have a thickness corresponding to that of the piezoelectric layer. The element may be used for an electro-mechanical transducer or a thermal-electric transducer.

Sheet-like piezoelectric element

The present invention provides a piezoelectric transducer and pickup means using the same for electrical string instruments, the transducer comprising a long and flat outer layer of flexible material and a flexible piezoelectric cable which is buried therein and has a center electrode, a piezoelectric layer formed on the outer periphery of the said electrode and an outer electrode formed on the outer periphery of the said layer, the stiffness thereof being enhanced by either using elastomer of the hardness of more than 80 as measured by the Spring Hardness Test Method in the Physical Testing Method for Vulcanizing Rubber of Japanese Industrial Standard (JIS K 6301) as the material for the outer layer, or by plaiting (braiding) metal wires or by winding the outer electrode of the piezoelectric cable in such a manner as to enable it to press against the piezoelectric layer.

Growing community of inventors

Aichi, Japan

Tsutomu Tsunooka