Futaba Denshi Kogyo K.k.

Futaba Corporation

Futaba Denshi Kogyo Kabushiki Kaisha

Neturen Co., Ltd.

Nanocarbon Research Institute Ltd.

Fumiaki Kataoka

Shigeo Itoh

Hitoshi Toki

Yoshitaka Sato

Yoshitaka Satoh

Yuji Nomura

Yoshiaki Inoue

Kazuhiro Kawasaki

Hisamitsu Takahashi

Seiji Yokota

Osamu Idohara

Akira Terajima

Makoto Takahashi

Hisashi Kanie

Eiji Osawa

Yoriko Suda

Takahiro Fujino

Kiyoshi Tamura

A dispersion of carbon nanoparticles is prepared by monodispersing carbon nanoparticles in water droplets of a reverse micelle solution in which the water droplets are coated with amphiphilic molecules and dispersed in an organic solvent. In a method of preparing the dispersion of carbon nanoparticles, carbon nanoparticles and a monodispersion function material, e.g., ammonia, for imparting a polarity to surfaces of the carbon nanoparticles are added to the reverse micelle solution. The solution is then stirred, so that the carbon nanoparticles whose surfaces have the polarity are monodispersed in the water droplets of the reverse micelle solution. Further, a metal alkoxide is added to the solution and then stirring them, so that the surfaces of the carbon nanoparticles are coated with oxide of the metal.

Dispersion of carbon nanoparticles and core-shell type carbon nanoparticles, and method of preparing the same

Ultradispersed ones of primary particles of nanometer-sized carbon are obtained by applying a wet-type milling method and/or a wet dispersion method to an aggregate structure of the primary particles to overcome van der Waals forces, by which forces the primary particles are held together to form the aggregate structure, whereby the ultradispersed primary particles are obtained in a colloidal dispersion on a large-scale basis at low cost without using any additive. In a method of manufacturing the ultradispersed primary particles, the wet-type milling method is carried out in a ball mill, preferably in combination with a high-energy ultrasonic-wave process carried out in a dispersing medium such as pure water, whereby a colloidal solution or slurry with a low-concentration of the primary particles ultradispersed in the dispersing medium is obtained.

Ultra-dispersed nanocarbon and method for preparing the same

The present invention provides a phosphor of formula A SiO :B (A is Y or Gd, and B is Ce or Tb) which is characterized by a surface elemental composition represented by (A&plus;B)/Si ranging from 1.5 to 2.5, wherein A is Y or Gd, and B is Ce or Tb; and method for preparing said phosphor. One embodiment of the method is as follows: a SiO powder is mixed with co-precipitate (Y, Ce) O (Ce/Y&equals;0.01), in an amount ranging from 10 to 110 mol % based on the amount of (Y, Ce) O , and the mixture is charged into the inner crucible of a double-walled aluminum crucible. After graphite is charged between the inner and outer crucible, the mixture is calcined at 1450&deg; C. for 2 hours to obtain an Y SiO :Ce phosphor. The luminous efficiency of a field emission display (FED) prepared employing the Y SiO :Ce phosphor was measured at an anode voltage of 600V, an electric power input of 30 Wp-p and a duty rate of 1/240. It is desirable that the relative amount of SiO based on the amount of (Y, Ce) O ranges from 40 to 70 mol %, preferably 50 to 60 mol %.

Phosphor and method for preparing same

A method for preparing a gallium nitride phosphor which is capable of emitting light at luminance increased to a degree sufficient to permit the phosphor to be practically used. A dopant compound containing elements reacted with H,and gasified by heating is arranged on an upstream side in a calcination oven in which NH,is flowed and a matrix element compound is arranged on the downstream side therein, resulting in calcination of the compound being carried out. This permits GaN to be surrounded with ammonia and the dopant during the calcination, so that the GaN phosphor may be fully doped with the dopant.

Method for preparing gallium nitride phosphor

A fluorescent material and a display device incorporating the fluorescent material are described. The fluorescent material is a mixture including a phosphor which is excitable at a voltage of 1 kV or higher for emitting light and a phosphor which is excitable at a voltage of 1 kV or lower for emitting light, wherein each phosphor emits light of the same color and the fluorescent material is luminous at an anode voltage of 2 kV or lower. The fluorescent display device accelerates electrons emitted from an electron source at an anode voltage of 2 kV or lower and rushes these electrons against an anode for exciting the fluorescent material present on the anode. The fluorescent material is a mixture as set forth above.

Fluorescent material and fluorescent display device

A phosphor capable of being kept from being affected by oxygen during production thereof, carrying out luminescence due to excitation by electrons, selectively realizing various luminous colors depending on selection of starting materials and exhibiting satisfactory luminance and life characteristics. The phosphor is represented by a chemical formula Ga.sub.1-x In.sub.x N:A (0.ltoreq.x&lt;0.8, A.dbd.Zn or Mg) and prepared by mixing starting materials containing at least an oxygen-free gallium compound and an oxygen-free doping substance to prepare a mixture and heating the mixture in a nitrogen-containing atmosphere.

Phosphor and method for producing same

A low-velocity electron excited phosphor having a composition represented by a general formula ZnO.multidot.(Al.sub.x, Ga.sub.1-x).sub.2 O.sub.3 :Mn, wherein X=0.001 to 0.3 mol. A content of Al in the phosphor is set be to within a range between 0.001 mol and 0.3 mol. The range permits a variation in luminance of the phosphor to be within .+-.30% and initial luminance of the phosphor to be significantly increased, resulting in the phosphor being suitable for use for a fluorescent display device.

Low-velocity electron excited phosphor

A phosphor is disclosed which is suitable for use for a fluorescent display device and driven at a driving voltage as low as 1 kV or less and free of S and Cd. Compounds of Ti, alkaline earth metal and an element of Group 13 of the periodic table in predetermined amounts are heated at 1100.degree. to 1400.degree. C. for calcination, resulting in a solid solution of the rare earth element and one element of Group 13 being formed in a phosphor matrix made of an oxide of alkaline earth metal and Ti. An example of the phosphor is SrTiO.sub.3 :Pr,Al exhibiting a red luminous color.

Phosphor and fluorescent display device

A low-velocity electron excited phosphor having a composition represented by a general formula ZnO.multidot.(Al.sub.x, Ga.sub.l-x).sub.2 O.sub.3 :Mn, wherein X=0.001 to 0.3 mol. A content of Al in the phosphor is set be to within a range between 0.001 mol and 0.3 mol. The range permits a variation in luminance of the phosphor to be within .+-.30% and initial luminance of the phosphor to be significantly increased, resulting in the phosphor being suitable for use for a fluorescent display device.

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Mobara, Japan

Fumiaki Kataoka