Hitachi, Ltd.

Noriyuki Taguchi

Tadashi Fujieda

Kishio Hidaka

Tokio Isogai

Mitsuo Hayashibara

Katsuo Abe

Gyozo Toda

Takashi Kuroki

Shinzou Ikeda

Akira Ikegami

Masami Masuda

Tsuyoshi Fujita

Hirayoshi Tanei

Nobuyuki Sugishita

Takashi Nishiguchi

Tatsuhiro Suzuki

Hiroshi Ohtsu

Shoosaku Ishihara

Syoosaku Ishihara

Tsuyoshi Fuzita

The purpose of the present invention is to provide an easy-to-manufacture electromagnetic wave absorption material usable from submillimeter wave region to millimeter wave region with an excellent radio wave absorbing performance and a variety of usage thereof. The present invention is characterized by an electromagnetic wave absorption material comprised of a dispersions of at least one of the materials: a multi-layer hollow globule of carbon, a schungite carbon, and the schungite ore; mixed into a matter having a high electrical resistivity. The invention is further characterized by an electronic device, an optical transmission module, an optical reception module, a high frequency telecommunication equipment, and a stop-free automated tollgate system, wherein at least a part of their board, electronic element, and circuit wiring are covered with said electromagnetic wave absorption material.

Electromagnetic wave absorption material and an associated device

An electromagnetic wave absorption material includes a dispersions of at least one of the materials: a multi-layer hollow globule of carbon, a schungite carbon, and the schungite ore; mixed into a matter having a high electrical resistivity. The invention is further characterized by an electronic device, an optical transmission module, an optical reception module, a high frequency telecommunication equipment, and a stop-free automated tollgate system, wherein at least a part of their board, electronic element, and circuit wiring are covered with said electromagnetic wave absorption material.

In a rear projection screen, a plurality of convex lenses of the prescribed configuration are made of photoresist and formed and arranged on a surface or surfaces of a substrate in the prescribed pattern. In case that the convex lenses are formed in the shapes of ellipsoid, the longer radial direction of the ellipsoid is made to coincide with the horizontal direction and shapes of the lenses are changed gradually from the center of the screen to the extremity thereof. Bottom surfaces of non-lens boundary grooves between adjacent convex lenses are made rougher than the convex lens surfaces. A screen manufacturing method comprises the steps of applying photoresist onto a surface or surfaces of a substrate, exposing a patttern of boundary grooves onto the photoresist by photolithography, forming the boundary grooves by etching, and heating and melting the photoresist which is formed with the boundary grooves so as to form a plurality of convex lenses having the prescribed configuration. Further, it is possible to form a plurality of convex lenses of the prescribed configuration by rotating the substrate about the center thereof in the horizontal plane following the heating and melting step. In addition, it is possible, in forming the boundary grooves, to change the setting conditions of etching so that the bottom surfaces of the boundary grooves are made rougher than the convex lens surfaces.

Rear projection screen and manufacturing method therefor as well as

A ceramic wiring board which comprises ceramic part in which through-holes are made, sintered wiring pattern part provided on the surface of said ceramic part and sintered conductor part filled in said through-holes shows much decrease in cracks at the through-hole part caused by sintering and remarkable reduction in moisture absorbency when the ceramic part comprises ceramic containing a sintering assistant and the sintered conductor part comprises a metal containing the same sintering assistant as that present in said ceramic part.

Ceramic wiring boards

A ceramic multilayer circuit board is provided by sintering a multilayer wiring substrate containing alumina as a main component, which was prepared by the green sheet process, nickel plating and gold plating in this order on the superficial wiring conductor layer, printing a thick film conductor paste on the gold plating layer, firing the printed substrate and finally printing a thick film resistor paste on at least part of the thick film conductor layer and firing to form a thick film resistor layer.

Ceramic multilayer circuit board and a process for manufacturing the same

A low temperature-sinterable dielectric composition is provided, whose sintered composition when prepared by firing a uniform mixture consisting of lead ferrotungstate, lead titanate and manganese dioxide at a temperature of not higher than 1,000.degree. C. has the general formula A.Pb(Fe.sub.2/3 W.sub.1/3).sub.1-x Ti.sub.x O.sub.3 +B.MnO.sub.2, wherein 0.005.ltoreq..times..ltoreq.0.65, A=0.95-0.9995, and B=0.0005-0.05, a relative dielectric constant of at least 2,000 at 25.degree. C., a dissipation factor (tan .delta.) of not more than 5% at 25.degree. C., and a specific resistance of at least 10.sup.9 .OMEGA..cm at 25.degree. C. Also provided is a thick film capacitor having a dielectric layer prepared from said composition.

Low temperature-sinterable dielectric composition and thick film

A dielectric paste for a thick film capacitor comprises barium titanate powder, glass frit, magnetite powder, an organic vehicle and a surface-active agent. A dielectric constant higher than 1,100 is obtained by firing at a temperature of 900.degree. C. or lower.

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Yokohama, Japan

Noriyuki Taguchi