Futaba Denshi Kogyo Kabushiki Kaisha

Futaba Denshi Kogyo K.k.

Futaba Denshi Kogya K.k.

Yoshitaka Satoh

Hitoshi Toki

Shigeo Itoh

Fumiaki Kataoka

Kiyoshi Morimoto

Yoshihisa Yonezawa

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 heat-treating method and an apparatus therefor capable of providing a phosphor exhibiting improved crystallizability and increased in concentration of a luminous center therein. A phosphor is heated and rapidly cooled in atmosphere gas of a predetermined pressure. The pressure substantially restrains decomposition and scattering of the phosphor during heating and cooling of the phosphor.

Phosphor heat-transfer method and apparatus therefor

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.

A low-velocity electron excited phosphor capable of exhibiting increased luminance and a stabilized blue tone. The phosphor is formed of ZnO.Ga.sub.2 O.sub.3 doped with Li and P, wherein the Li and P are doped in amounts of 500 to 2300 ppm and 100 ppm or less, respectively. Such construction permits the phosphor to exhibit a blue luminous color of a desirable tone having a value y of 0.05 to 0.25 in a CIE chromaticity diagram.

Low-velocity electron excited phosphor of blue luminous color

A phosphor producing process capable of providing a phosphor of good quality in a reduced period of time. A Li compound acting as a doping agent is added prior to primary calcination so that it may also act as a flux and removed by washing prior to secondary calcination. A ZnO.Ga.sub.2 O.sub.3 solid solution thus obtained is activated in the secondary calcination using an atmosphere in which reducing gas and Zn gas are mixed. Thus, a ZnO.Ga.sub.2 O.sub.3 :Li, P phosphor is which the molar ratio between Zn and Ga.sub.2 O.sub.3 is 1:1 and of which crystals exhibit good surface conditions can be produced in a reduced period of time.

Process for producing phosphor

A fluorescent composition capable of emitting light of various luminous colors under electron or ultraviolet excitation and a fluorescent luminous device having mounted such a fluorescent composition mounter therein. The fluorescent composition has a general formula of ZnO.Ga.sub.2 O.sub.3 and emits light of a luminous spectrum distributed at an ultraviolet or visible region. The fluorescent composition includes a matrix of ZnO.Ga.sub.2 O.sub.3 and Cd doped in the matrix. The fluorescent luminous device includes at least one ZnO.Ga.sub.2 O.sub.3 :Cd phosphor deposited on anode conductors and at least one luminous display section having an ultraviolet excitable visible light emitting phosphor deposited thereon within a region of radiation of ultraviolet rays emitted from the ZnO.Ga.sub.2 O.sub.3 :Cd phosphor.

Growing community of inventors

Mobara, Japan

Yoshitaka Satoh