Tdk Corporation

Tdk Electronics Company, Limited

Ohkawara Kakohki Co., Ltd.

Mitsubishi Denki Kabushiki Kaisha

U.S. Philips Corporation

Mizusawa Industrial Chemicals, Ltd.

Shoichi Iwaya

Hitoshi Masumura

Hiroki Takahashi

Katsumi Kobayashi

Takashi Ito

Masaaki Ohkawara

Sho Masujima

Hiromi Adachi

Munemitsu Hamada

Haruo Taguchi

Hisao Abe

Hitoshi Tanaka

Koji Takahashi

Kenichi Horie

Teiji Sato

Yasunobu Oikawa

Setsuo Sasaki

Tomohiro Sogabe

Teruo Taguchi

Norimasa Sakamoto

Hiroyuki Satoh

Tsunehiko Yoshioka

Shigeya Takahashi

Seiichiro Yamamoto

Masaru Fukuda

Yoshifumi Midori

Yoshishige Towatari

Mutsuo Koganebuchi

Seizou Tanaka

Hitoshi Nakata

Takayuki Ishizuki

Yuuiti Sannohe

Yasutaka Oyamada

Hiroaki Abe

Minoru Sato

Takeyoshi Satoh

A dielectric filter includes a first dielectric layer containing at least a pair of strip-line resonators to be electromagnetically coupled to each other. Second and third dielectric layers are disposed in an opposed relation to each other with the first dielectric layer sandwiched therebetween and having substantially the same dielectric constant (K1). Each of the second and third dielectric layers contains at least one shield electrode. The dielectric filter further includes fourth and fifth dielectric layers which have substantially the same dielectric constant (K2) and are interposed between the first and second dielectric layers and between the first and third dielectric layers, respectively. The dielectric constant (K2) of the fourth and fifth dielectric layers is selected to be less than any one of the dielectric constant (K1) of the second and third dielectric layers and the dielectric constant (K3) of the first dielectric layer.

Dielectric filter

The present invention provides an electrode for a ceramic electrode fluorescent discharge lamp; an electrode material for a discharge lamp, which has high electron flow density, high thermal shock resistance, and reduced deterioration due to sputtering; and also a method for manufacturing the same. The invention makes it possible to reduce the tube diameter of the ceramic electrode fluorescent discharge lamp. An electrode material for a discharge lamp is obtained from a first component of 0.5 to 1.5 mols of BaO, CaO or SrO, a second component of 0.05 to less than 0.3 mols or more than 0.7 to 0.95 mols of ZrO,or TiO,, and a third component of 0.025 to less than 0.3 mols of V,O,, Nb,O,, Ta,O,, Sc,O,, Y,O,, La,O,, Dy,O,, or Ho,O,, or 0.05 to less than 0.15 mols or more than 0.35 to 0.95 mols of HfO,, CrO,, MoO,or WO,. This electrode material is granulated and is turned into a massive, granular, or porous electrode material. This is placed in a cylindrical semiconductor ceramic container with a closed bottom and is reduced and fired to prepare an electrode. A mercury dispenser of the ceramic electrode fluorescent discharge lamp is disposed in series between the cylindrical semiconductor ceramic container with a closed bottom and a lead-in portion of the lead wire.

Discharge lamp electrode

A process for producing a columbite-type niobate and a process for producing a niobium-containing lead-type perovskite compound using the columbite-type niobate. A precursor slurry of a columbite compound composed of a fresh niobium hydroxide, a metal acetate and ammonium aqueous solution is spray-dried, and is calcined at 500.degree. C. or higher to obtain a crystalline columbite-type compound having grain sizes of 1 .mu.m or smaller to which was then mixed a lead component. The mixture is calcined, pulverized and is sintered at a temperature of 800.degree. to 1100.degree. C. to synthesize a highly dielectric material of a niobium-containing lead-type composite perovskite. The precursor of columbite is calcined at 500.degree. to 1100.degree. C. to obtain fine columbite-type niobate crystals of grain sizes of 1 .mu.m or smaller. A lead-type perovskite compound using the above crystals can be sintered at a temperature of as low as 950.degree. C. or lower, and the sintered product thereof has a homogeneous and fine texture and excellent dielectric properties that could not be obtained by the conventional solid-phase process.

Process for producing columbite-type niobate and process for producing

In conventional fluidized granulators whose housing is made of a steel plate, a powder tends to cause blocking if it is highly hygroscopic, and the bag filter used therein causes clogging. These problems have been solved in the present invention by forming the housing of a fluidized granulator with a porous membrane in place of the conventional steel plate. This fluidized granulator produces granules or a coated powder by spraying powder with water, a binder fluid or a coating fluid while maintaining the powder in a fluidized state.

Fluidized bed granulator

A semiconductive ceramic composition capable of permitting its resistance-temperature characteristics and resistance to be controlled as desired and a firing temperature of the composition to be lowered to a degree sufficient to facilitate the mass-production at a low cost. The composition contains a main component consisting of SrO, PbO and TiO.sub.2 and is subjected to firing in an oxidizing atmosphere. The composition may contain at least one of SiO.sub.2 and M as a minor component. A variation in amount of the main and minor components permits characteristics and properties of the composition to be varied as desired.

Semiconductive ceramic composition

Spray dryer

The spray drying process and the apparatus therefor, of the present invention use a spray drying chamber formed by a heat-resistant porous membrane. Said porous membrane enables rapid separation of a discharge gas and a produced powder and accordingly total recovery of the produced powder from the spray drying chamber. Therefore, there occurs no nonuniformity in product composition; cleaning and blowing-off of adhered fine powder can be conducted rapidly and easily even in frequent product changes inevitable with a less grade larger quantity production system; as a result, a fine powder of higher quality and higher purity can be produced.

Spray drying process and apparatus therefor

The spray drying process and the apparatus therefor, of the present invention use a spray drying chamber formed by a heat-resistant porous membrane. Said porous membrane enables rapid separation of a discharge gas and a produced powder and accordingly total recovery of the produced powder from the spray drying chamber. Therefore, there occurs no nonuniformity in product composition; cleaning and blowing-off of adhered fine powder can be conducted rapidly and easily even in frequent product change inevitable with a less grade larger quantity production system; as a result, a fine powder of higher quality and higher purity can be produced.

A through-type capacitor capable of effectively preventing peeling of an insulation resin from a ceramic dielectric and providing an insulation case of the capacitor with heat resistance, tracking resistance, arc resistance to improve burning resistance of the case, resulting in safely and positively operating for a long period of time. The capacitor includes an insulation case arranged to surround a ceramic dielectric and filled with insulation resin materials to embed the ceramic dielectric in the materials. The insulation case includes a first insulation case member formed of thermoplastic resin and arranged to surround the ceramic dielectric and a second insulation case member formed of thermosetting resin and integrally mounted on the first insulation case member.

Through-type capacitor and magnetron using same

Lighting apparatus for a discharge lamp

A discharge lamp lighting device comprises a discharge lamp (1) with a pair of filaments (101a, 101b), an inductive balast (2) coupled with said lamp (1) and a power supply, a non-linear dielectric element (4) coupled across said lamp (1), a semiconductor switch (3) coupled substantially parallel with said non-linear dielectric element (4), and delay means ((6,7,303c,304b,303d), (8,303c,304b,303b), (9,10,60), (6,11)) for shifting firing phase of said semiconductor switch (3) so that a spike voltage induced by said non-linear dielectric element increases gradually for every cycle of a power supply voltage.

Discharge lamp lighting device

Current restriction element responsive to applied voltage

A D-E hysteresis loop of ferroelectrics known in the art has a square shape when the ferroelectrics are a BaTiO.sub.3 single crystal. Such ferroelectrics are used as a non-linear dielectric element of, for example a pulse generating device. The non-linear dielectric element according to the present invention consists of a polycrystal mainly composed of Ba(Ti.sub.0.90-0.98 Sn.sub.0.02-1.00)O.sub.3 and having an average grain diameter of from 10 to 60 .mu.m. The non-linearity is excellent and the temperature dependence of the non-linearity is considerably low.

Non-linear polycrystalline barium titanate-type dielectric element

An improved starter switch which provides a rapid firing of a fluorescent lamp within 0.8 second has been found. An external appearance and the size of the present starter switch are almost the same as those of a prior glow switch which is slow to fire a fluorescent lamp, therefore, the present starter switch is replaceable to a prior glow switch by merely inserting the present starter switch to a socket of a prior glow switch. The present starter switch has a connector cap which is to be able to be engaged with a socket for a glow switch, a printed circuit board mounting circuit components and connected to said connector cap by lead lines, and a housing fixed to said cap and covering said printed circuit board. The circuit elements mounted on the printed circuit board include at least a non-linear capacitor which has a saturation characteristics between a voltage applied to the capacitor and the charge stored in the same, and a semiconductor switch which conducts upon the application of the voltage higher than a predetermined threshold voltage and holds the conductive status until the current in the same reaches almost zero. Following to the switching OFF of the semiconductor switch when the source current is almost zero but the source voltage is almost maximum due to the presence of an inductive ballast, the non-linear capacitor is charged but is saturated in a short time, then, the charge current of the capacitor is interrupted. The interruption of the charge current of the non-linear capacitor induces the high firing pulse voltage in a ballast inductor which is connected in series with a fluorescent lamp, and said pulse voltage fires a lamp.

Rapid starter switch for a fluorescent lamp

A capacitor trimming system for a quartz-crystal oscillator in a watch and/or a clock for providing a punctual watch and/or a clock has been found. The system comprises an oscillation circuit including at least a quartz-crystal piece, a trimmer capacitor for adjusting the oscillating frequency of the quartz-crystal piece, a semiconductor electronic circuit for operating said quartz-crystal piece, and apparatus for adjusting automatically the trimmer capacitor so that the oscillating frequency becomes the same as the desired reference frequency. The trimmer capacitor comprises of at least a fixed outer trimming electrode, an inner common electrode fixed parallel to said trimming electrode and a dielectric body sandwiched between the two electrodes. The trimming electrode is disposed in the air for enabling the trimming of the area of the trimming electrode, and the trimming electrode has a coarse adjustment portion parallel and aligned with said common electrode and a fine adjustment portion attached to the same plane of that of the coarse adjustment portion but outside of the common electrode. The oscillation frequency of the quartz-crystal piece is automatically picked up and the frequency is compared with the desired reference frequency, and according to the result of the comparison, the trimming electrode is trimmed so that the oscillating frequency becomes the desired reference frequency. The trimming is carried out first for the coarse trimming portion, and secondly for the fine adjustment portion.

Capacitor trimming system in a quartz-crystal oscillator

Growing community of inventors

Tokyo, Japan

Shoichi Iwaya