Matsushita Electric Industrial Co., Ltd.

Fumio Fukushima

Tsuneharu Nitta

Yoji Fukuda

Shigeru Hayakawa

Tomizo Matsuoka

Yosuke Fujita

Mitsuo Makimoto

Morikazu Sagawa

Kazuhiro Eguchi

Jiro Terada

Masakazu Fukai

Katsumi Sasaki

Hiromitsu Taki

Haruyoshi Endo

Takehiko Yoneda

Yoshinobu Tsujimoto

Koji Nishimura

Shinji Sugai

A flat type dielectric filter comprises a substantially U-shaped strip line formed such that each center frequency of spurious output deviates from each odd number frequency times the center frequency of the dielectric filter. That is, it comprises a first portion so curved to form an open loop and two second portions formed to have a larger width than the first portion, each of the second portions being provided to an end of the first portion such that each extends in the opposite direction to the other. In this filter, input/output electrodes confronting ends of U-shaped strip line can be formed on a different layer from the layer where the resonator is formed in order to reduce its size. Reduction of size can be obtained by vertically folding the U-shaped strip line extending horizontally. Terminals of this filter formed on the side surface have a first layer formed on the side surface and a second layer formed on the first layer. The first layer is made of silver, the second layer nickel, or the first layer copper, the second layer solder. This filter has two conducting plates sandwiching dielectric substrates including each resonator, the conducting plate being coated with a epoxy resin or dielectric substance.

Flat type dielectric filter

A resonator having a strip line, the strip line comprising: a first portion forming an open loop; and two second portions, each provided to each end of the first portion, the second portions facing each other with a given distance therebetween, the distance and length of the second portion being determined such that necessary capacitance is provided. The capacitor is provided instead of a discrete capacitor for saving space and for reducing dielectric loss therein. A second resonator further comprises second and third capacitor having a semicircle strip-line patterns for providing capacitances between ends of the first portion and grounded planes which decrease the resonance frequency so that size of the second resonator are reduced. A third resonator also comprises the first capacitor, but arranged outside of the first portion. Capacitance of the first capacitor can be increased by teeth provided to the second portions. A filter comprises plural third resonators so arranged that coupling between the resonators is obtained by one selected from magnetic-field coupling through the first portions, electromagnetic-field coupling through first and second portions, and electric-field coupling through second portions.

Resonator and a filter including the same

A humidity sensitive device for sensing the humidity of an ambient humidity comprising a humidity sensitive resistor 15 which comprises as main component at least one selected from the group consisting of ZrO.sub.2, TiO.sub.2, Nb.sub.2 O.sub.5 and Ta.sub.2 O.sub.5 and an electric heater 13 applied near and for heating and retaining the humidity sensitive resistor 15 at a temperature above 200.degree. C. The humidity sensitive resistor 15 and a fixed resistor are series connected across an AC voltage source 17, and a voltage across the humidity sensitive resistor 15 or the fixed resistor 16 is rectified by a AC/DC converter and compared with a reference voltage by a comparator, thereby an output responding to humidity in the atmosphere can be measured for a wide range of temperature.

Humidity sensitive device

A ceramic luminescent device, in which a luminescent screen of zinc sulfide layer with luminescent impurities is formed on a translucent zinc oxide sintered body, and the luminescent light emitted from said luminescent screen is derived through said zinc oxide body. The device can be constructed in a manner that said luminescent screen is excited either by an electric field or electron beam.

Ceramic luminescent device

Highly densed zinc sulfide ceramic materials, which essentially comprise zinc sulfide and alkali metals and/or alkaline earth metals and impurities acting as luminescent center, and which show a high brightness of cathode luminescence under irradiation of electron beam having a low energy, are easily made in the form of the sintered material, by heating the mixture of the said materials in inert or sulfuring atmosphere.

Zinc sulfide ceramic material and cathode ray tubes using the same

Flake-like ceramic particles of zinc sulfide phosphor and method of preparing the same including the steps of preparing flake-like particles of basic zinc sulfate crystal doped with activator, sulfurizing in the particles carbon disulfide, and heating the sulfurized particles in hydrogen sulfide. Particularly by steeping said particles in a solution of alkaline earth metal salt prior to or after sulfurizing, grain growth in ceramic particles can be improved.

Method of preparing flake-like ceramic particle of zinc sulfide phosphor

Basic zinc compound flake-like crystalline material suited for use in crystal-oriented electronic devices and method for preparation thereof comprising the steps of preparing a solution including at least zinc ions and sulfate ions, and causing precipitation of zinc sulfate crystals by causing a reaction of components of said solution with alkali when said solution is at a temperature in the range 50.degree. to 100.degree. C. and has a pH value of in the range 4 to 6.5.

Basic zinc compound flake-like crystalline particle and method for

In the firing of a cerium-activated Y.sub.2 O.sub.3 -SiO.sub.2 system phosphor such as Y.sub.2 SiO.sub.5 :Ce and Y.sub.2 Si.sub.2 O.sub.7 :Ce, the improvement of adding BaF.sub.2 in a mol ratio of BaF.sub.2 /Y.sub.2 O.sub.3 of 0.01-0.1 is disclosed which increases the luminosity, emission intensity or both of the phosphor. Phosphors having improved properties are conveniently prepared according to the disclosed process.

Growing community of inventors

Miyazaki, Japan

Fumio Fukushima