Tdk Corporation

Other

Dai Matsuoka

Yo Saito

Katsunari Moriai

Masatada Yodogawa

Yuji Terada

Hitoshi Tanaka

Naoyoshi Yoshida

Koichi Ishii

Naoki Chida

Tadashi Ogasawara

Izuru Soma

Makoto Takahashi

Munemitsu Hamada

Hideaki Sone

Hiraku Harada

Akira Takeishi

Hideaki Fukuzawa

Takahiro Sato

Tomohito Mizuno

Masahito Furukawa

Tetsuya Shibata

Jitsuo Kanazawa

Kaname Ueda

Makoto Numata

Takeshi Yanata

Masuo Okada

Takehiko Abe

Masahiko Konno

Nobuei Shimojo

Masaru Fukuda

Masaaki Taniguchi

Kimio Suto

Toshio Marui

Hitomi Naitou

Toshiyuki Yamazaki

Kaneo Mori

Hisayoshi Saito

Hidetaka Kitamura

Takahiro Sawaguchi

An optical sensor includes a wavelength filter configured to transmit light in a specific wavelength range and a magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer. The light passing through the wavelength filter is applied to the magnetic element and the light applied to the magnetic element is detected.

Optical sensor, optical sensor unit, optical sensor device, and information terminal device

A chip-type electronic component has: a ceramic element body; a plurality of first and second internal electrodes arranged in the ceramic element body so as to be opposed at least in part to each other; a first external connection conductor to which the plurality of first internal electrodes are connected; a second external connection conductor to which the plurality of second internal electrodes are connected; first and second terminal electrodes; a first internal connection conductor arranged in the ceramic element body and connecting the first external connection conductor and the first terminal electrode; and a second internal connection conductor arranged in the ceramic element body and connecting the second external connection conductor and the second terminal electrode. The number of the first internal connection conductor is set to be smaller than the number of the first internal electrodes and the number of the second internal connection conductor is set to be smaller than the number of the second internal electrodes.

Chip-type electronic component

A varistor has a ceramic composition to exhibit nonlinear voltage-current characteristics, and at least two electrodes arranged to sandwich at least a portion of the ceramic composition. The ceramic composition contains a mixture phase in which a first phase containing zinc oxide as a major component, and a second phase comprised of an oxide of Ca and Si are mixed.

Varistor

A nonlinear resistor ceramic composition has a major component containing zinc oxide, a first minor component containing an oxide of a rare-earth metal, a second minor component containing an oxide of Ca, and a third minor component containing an oxide of Si. A percentage of the second minor component to 100 moles of the major component is in the range of 2 atomic %&#x2266;the second minor component&#x3c;80 atomic % in terms of Ca. A percentage of the third minor component to 100 moles of the major component is in the range of 1 atomic %&#x2266;the third minor component&#x3c;40 atomic % in terms of Si. An atomic ratio of Ca to Si (Ca/Si) is not less than 1.

Nonlinear resistor ceramic composition, electronic component, and multilayer chip varistor

In a varistor element, Ca exists in the grain interior of grains consisting primarily of ZnO in a varistor element body and Ca also exists in a grain boundary. In this crystal structure Ca replaces oxygen defects in the grain interior of grains consisting primarily of ZnO, in the varistor element body to make the ceramic structure denser Such crystal structure also decreases a ratio of an element tending to degrade the stability of the temperature characteristic of the varistor element, e.g., Si as a firing aid, in the grain boundary between grains. As a result, the varistor element has a stable temperature characteristic, which can decrease change in capacitance and tan &#x3b4; (thermal conversion factor of resistance) against change in temperature.

Varistor element

A varistor is provided with a varistor element, and an external electrode disposed on the varistor element. The varistor element contains ZnO as a principal ingredient and contains a rare-earth element and Ca. The external electrode is formed by baking on an outer surface of the varistor element and contains Pt. When the external electrode is formed by baking on the varistor element, a compound of the rare-earth element and Pt and a compound of Ca and Pt are formed near an interface between the varistor element and the external electrode, and exist there. The existence of these compounds enhances the bonding strength between the varistor element and the external electrode.

Varistor and method of producing varistor

A varistor has a varistor element body, and an external electrode disposed on the varistor element body. The varistor element body contains ZnO as a principal component, and a rare-earth metal. The external electrode has an electrode layer. The electrode layer is formed on an external surface of the varistor element body by simultaneous firing with the varistor element body. The electrode layer contains Pd.

Varistor and method of producing the same

As for the voltage non-linear resistance element layer, sintered body (ceramics) having ZnO as main component is used. Said sintered body comprises Pr, Co, Ca and Na are added. Therefore, the ranges are 0.05 to 5.0 atm % of Pr, 0.1 to 20 atm % of Co, 0.01 to 5.0 atm % of Ca and 0.0001 to 0.0008 atm % of Na. When it is within the range, the capacitance changing rate at 85&#xb0; C. with standard being 25&#xb0; C. can be made to equal or less than 10%.

Voltage non-linear resistance ceramic composition and voltage non-linear resistance element

An object of the present invention is to provide a multilayer filter constructed so as to be less likely to suffer peeling between a varistor part and an inductor part. A multilayer filteras a preferred embodiment has a structure in which a varistor partand an inductor part are stacked. The varistor partconsists of a stack of varistor layerswith internal electrodes, and the varistor layers contain ZnO as a principal component, and contain at least one element selected from the group consisting of Pr and Bi, Co, and Al as additives. The inductor partconsists of a stack of inductor layers-with conductor patterns-, and the inductor layers contain ZnO as a principal component and substantially contain neither Co nor Al.

Multilayer filter

A multilayer chip varistor comprises a multilayer body in which a plurality of varistor portions are arranged along a predetermined direction, and a plurality of terminal electrodes. Each varistor portion has a varistor layer to exhibit nonlinear voltage-current characteristics, and a plurality of internal electrodes disposed so as to interpose the varistor layer between them. Each terminal electrode is disposed on a first outer surface parallel to the predetermined direction out of outer surfaces of the multilayer body and is electrically connected to a corresponding internal electrode out of the plurality of internal electrodes. Each of the plurality of internal electrodes includes a first electrode portion overlapping with another first electrode portion between adjacent internal electrodes out of the plurality of internal electrodes, and a second electrode portion led from the first electrode portion so as to be exposed in the first outer surface. The plurality of terminal electrodes are electrically connected via the respective second electrode portions to the corresponding internal electrodes.

Multilayer chip varistor

A filter circuit has first and second varistors, a resistance, an input terminal, an output terminal, and a ground terminal. The resistance is connected between the first and second varistors. The input terminal is connected to a junction between the first varistor and resistance through a first coil. The output terminal is connected to a junction between the second varistor and resistance through a second coil. The ground terminal is connected to a side of the first varistor opposite from the resistance and a side of the second varistor opposite from the resistance.

Filter circuit and filter device

A varistor element comprises a varistor element body, a plurality of inner electrode pairs, a connecting conductor, and a plurality of terminal electrodes. The varistor element body has first and second main faces opposing each other. Each inner electrode pair has first and second inner electrodes. The first and second inner electrodes are arranged so as to oppose each other at least partly within the varistor element body. The connecting conductor is arranged on the first main face so as to electrically connect the first inner electrodes in a predetermined inner electrode pair in the plurality of inner electrode pairs to each other. The terminal electrodes are provided so as to correspond to the second inner electrodes in the plurality of inner electrode pairs, and are arranged on the second main face so as to electrically connect with the second inner electrodes.

An object of the present invention is to provide a small surge absorption element that exhibits superior impedance matching even for high-speed signals and a surge absorption circuit. The surge absorption element comprises first and second inductor sections and first and second surge absorption sections. The first inductor section comprises first and second coils and the second inductor section comprises third and fourth coils. By suitably setting the coupling coefficients between the respective coils and the induction coefficients of the first to fourth coils, image impedance with an even frequency characteristic can be implemented over a wide area. Further, because the first to fourth coils have a positive magnetically coupled state with respect to one another, the induction coefficients of the first to fourth coils can be reduced in comparison with a case where the first to fourth coils are not afforded a positive magnetically coupled state.

Surge absorption element and surge absorption circuit

As for the voltage non-linear resistance element layera sintered body having ZnO as a main component is used. In this sintered body, Pr, Co, Ca, and either Cu or Ni are added. The ranges are; 0.05 to 5.0 atm % of Pr, 0.1 to 20 atm % of Co, 0.01 to 5.0 atm % of Ca, and 0.0005 to 0.05 atm % of either Cu or Ni. Within these ranges, the capacitance changing rate can be made to equal or less than 10 % at 85&#xb0; C. when 25&#xb0; C. is taken as standard.

A light emitting device has a semiconductor light emitting element and a multilayer chip varistor. The multilayer chip varistor has a multilayer body with a varistor portion therein, and a plurality of external electrodes disposed on an outer surface of the multilayer body. The varistor portion has a varistor layer containing ZnO as a principal component and exhibiting nonlinear voltage-current characteristics, and a plurality of internal electrodes arranged to interpose the varistor layer between them. Each of the external electrodes is connected to a corresponding internal electrode out of the plurality of internal electrodes. The semiconductor light emitting element is disposed on the multilayer chip varistor. The semiconductor light emitting element is connected to corresponding external electrodes out of the plurality of external electrodes so as to be connected in parallel to the varistor portion.

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Tokyo, Japan

Dai Matsuoka