Abstract: A color cathode ray tube is provided with an electron gun having a voltage-dividing resistor having a stable and good voltage supplying function. The voltage-dividing resistor has an insulating substrate on which a resistor pattern and a terminal-connecting conductive film are formed, and a terminal having a first flange portion, a connecting portion, a tubular portion and a second flange portion. The first flange portion partly has a convex portion for electrical connection to the terminal-connecting conductive film, and the second flange portion is doubled. This construction provides reliable electrical connection between the terminal and the terminal-connecting conductive film.

Abstract: A red emitting phosphor comprises a yttrium oxysulfide phosphor as a base material. A red emitting phosphor of medium particle size type has such a particle size distribution that a content of a component of a particle diameter of less than 4.0 &mgr;m is 15% or less, that of a component of a particle diameter of 4.0 &mgr;m or more and less than 8.0 &mgr;m is 75% or more, and that of a component of a particle diameter of 8.0 &mgr;m or more is 10% or less. A red emitting phosphor of larger particle size type has such a particle size distribution that the content of a component of a particle diameter of less than 5.04 &mgr;m is 20% or less, that of a component of a particle diameter of 5.04 &mgr;m or more and less than 10.079 &mgr;m is 70% or more, and that of a component of a particle diameter of 10.079 &mgr;m or more is 10% or less. Phosphor layers employing these red emitting phosphors are excellent in denseness. Accordingly, a cathode ray tube of high contrast and high quality can be provided.

Abstract: Disclosed are a photosensitive resin composition which comprises: (C) a photopolymerizable unsaturated compound having an ethylenic unsaturated group; (D) a photopolymerization initiator which produces free radical by irradiation of active light; and (E) a surface treated phosphor, a photosensitive film and a process for preparing a fluorescent pattern using the same, and a plate for a display panel.

Abstract: The wavelength-converting casting composition is based on a transparent epoxy casting resin with a luminous substance admixed. The composition is used in an electroluminescent component having a body that emits ultraviolet, blue or green light. An inorganic luminous substance pigment powder with luminous substance pigments is dispersed in the transparent epoxy casting resin. The luminous substance is a powder of Ce-doped phosphors and the luminous substance pigments have particle sizes ≦20 &mgr;m and a mean grain diameter d50≦5 &mgr;m.

Abstract: A color cathode ray tube includes a phosphor screen, cathodes, a G1 electrode, a G2 electrode, a G4 electrode, a G5 electrode and an anode for focusing the electron beams on the phosphor screen. The G5 electrode is divided into plural sub-electrodes arranged to be supplied alternately with a first focus voltage and a second focus voltage, at least one electrostatic quadrupole lens is formed between two of the sub-electrodes supplied with the first and second focus voltages, respectively, at least one lens for correcting curvature of the image field is formed between two of the sub-electrodes supplied with the first and second focus voltages, respectively. The G4 electrode, the G5 electrode and the phosphor screen satisfy following inequalities: 0.0625×L (mm)≦B−20A/(3&phgr;)≦22.

Abstract: Phosphor powders and a method for making phosphor powders. The powders are oxygen-containing, such as metal oxides, silicates, borates or titanates and have a small particle size, narrow particle size distribution and are substantially spherical. The method of the invention advantageously permits the continuous production of such powders. The invention also relates to improved devices, such as display devices, incorporating the phosphor powders.

Abstract: 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.

Abstract: A method for forming a plurality of stripe-like phosphor layers on a surface of a substrate constituting a plasma display panel, the surface having a plurality of parallel ribs disposed thereon and grooves defined between two adjacent ribs, includes the steps of: molding a phosphor paste composed of a phosphor substance and a first synthetic resin into filament-like article; placing the molded filament-like article into each groove; filling the grooves with a solvent optionally containing a second synthetic resin compatible with the first synthetic resin; and conducting a sintering treatment of the substrate to form the phosphor layers in the grooves.

Abstract: Sulfur-containing phosphor powders, methods for making phosphor powders and devices incorporating same. The powders have a small particle size, narrow particle size distribution and are substantially spherical. The method of the invention permits the continuous production of such powders. The invention also relates to products such as display devices incorporating such phosphor powders.

Abstract: Color rendering indices Ra,8 between 80 and 90 and R9 greater than 20, and a color point on or near the Planckian curve, are achieved with a lamp vessel provided with a luminescent screen including a first luminescent substance which emits predominantly between 520 nm and 565 nm, a second luminescent substance which emits predominantly between 590 nm and 630 nm, and a third luminescent substance which emits predominantly in the range between 615 nm and 780 nm.

Abstract: A fluorescent lamp comprises at least one layer of a four-component phosphor blend for producing visible illumination having a white color. The quad-phosphor blend comprising a first and second red-emitting phosphor component with each red-emitting phosphor component having different visible emission spectrum principally in the 590 to 630 nm wavelength range. A third blue-emitting phosphor component has an emission spectrum principally in the 430 to 490 nm wavelength range. A fourth no-rare-earth green-emitting phosphor component has an emission spectrum principally in the 500 to 570 nm wavelength range. The relative proportions of the phosphor components are such that an enhanced color rendering index is produced as compared to tri-component blends formed from only three of the phosphor components.

Abstract: A phosphor composition selected from a range of phosphor compositions is provided for discharging spent electrons from a display screen of a luminescent display. The selected phosphor composition is a mixture of phosphor species, including a dielectric phosphor species capable of emitting visible green, blue or red light when subjected to excitation electrons at a relatively high voltage and a conductive phosphor species capable of emitting visible green, blue or red light when subjected to energized excitation electrons at a relatively low voltage. The display screen of the luminescent display is coated with the selected phosphor composition to form a cathodoluminescent layer on the screen. The cathodoluminescent layer is then selectively subjected to excitation electrons having a voltage within a predetermined broad range. The excitation electrons impart their energy to the phosphor composition causing it to emit visible green, blue or red light, thereby creating an image on the screen.

Abstract: The current coefficient and saturation brightness of a phosphor is increased by coating the surfaces of phosphor particles (11, 21, 41) constituting a powdered phosphor with layers (12, 22, 42), preferably composed of phosphor, of 5 .mu.m, or less in thickness. A cathode-ray tube using this phosphor has a high luminance and/or a high resolution. If the above phosphor contains phosphor particles covered with electrically conductive phosphor and is used for an electroluminescence device or a vacuum fluorescent display, the life time and stability are improved.

Abstract: A color cathode ray tube comprises a panel having an effective portion. The outer surface in the effective portion of the panel is substantially flat or forms a slightly curved plane with a small curvature. The inner surface of the panel has a substantially infinite curvature radius in a direction of the longer axis in at least a central portion of the panel and is curved in a direction of the shorter axis. A difference in thickness of the effective portion of the panel between the central portion and the edge portions diagonally apart from each other exceeds 8 mm and does not exceed 20 mm, and the transmittance of the glass in the central portion of the effective portion is at least 70%. The particular construction enables the vacuum envelope of the color cathode ray tube to exhibit a mechanical strength high enough to sufficiently withstand the atmospheric pressure, though the effective portion of the panel is flattened.

Abstract: The wavelength-converting casting composition is based on a transparent epoxy casting resin with a luminous substance admixed. The composition is used in an electroluminescent component having a body that emits ultraviolet, blue or green light. An inorganic luminous substance pigment powder with luminous substance pigments is dispersed in the transparent epoxy casting resin. The luminous substance is a phosphorous group of the general formula A.sub.3 B.sub.5 X.sub.12 :M, and the luminous substance pigments have particle sizes<20 .mu.m and a mean grain diameter d.sub.50 <5 .mu.m.

Abstract: A multi-stage process for preparing a phosphor product includes the stages of selecting precursors of a dopant and a host lattice as the phosphor starting materials, grinding the starting materials in an initial grinding stage for an initial grinding time period to produce an initial ground material having a smaller particle size distribution than the starting materials, firing the initial ground material in an initial firing stage at an initial firing temperature for an initial firing time period to produce an initial fired material, grinding the initial fired material in an intermediate grinding stage for an intermediate grinding time period to produce an intermediate ground material having a smaller particle size than the initial fired material, wherein the intermediate grinding time period is substantially less than the initial grinding time period, firing the intermediate ground material in an intermediate firing stage at an intermediate firing temperature for an intermediate firing time to produce an in

Abstract: In a cathode-ray tube, a phosphor screen is formed by employing a blue phosphor obtained by mixing Cu with ZnS:Ag, Al in a normal solid phase reaction, then forming the phosphor solution on the inner surface of a panel of a cathode ray tube. The resulting cathode-ray tube can have increased brightness with negligible loss of chromacity. The amount of Cu as a co-activator in the blue phosphor can range between 0.6 to 1.5 ppm. In a preferred embodiment, the blue phosphor has a chromacity y-value of 0.089.

Abstract: The invention relates to a display screen having a phosphor layer of a phosphor composition of a phosphor coated with an oxygen compound of one of the elements magnesium, calcium, barium, zinc and aluminium, and with colloidal SiO.sub.2 having an average particle size of 70 nm.ltoreq.d.ltoreq.130 nm. The invention further relates to a phosphor composition of a phosphor coated with an oxygen compound of one of the elements magnesium, calcium, barium, zinc and aluminium, and with colloidal SiO.sub.2 having an average particle size of 70.ltoreq.d.ltoreq.130 nm, and to a method of manufacturing the phosphor composition.

Abstract: A method of manufacturing a phosphor screen for a flickerless cathode ray tube comprising the steps of forming red and green phosphor layers on a panel for a cathode ray tube on which a black matrix is formed, forming a blue phosphor layer on said panel on which a black matrix is formed by coating the blue phosphor slurry and drying and forming a double phosphor layer by coating an ultraviolet phosphor slurry on said blue phosphor layer and drying, is provided.

Abstract: A CRT 10 has an evacuated envelope 11 comprising a funnel 15 having a neck 14 and an open end. The funnel 15 is sealed at the open end to a faceplate panel 12 having a luminescent screen 22 formed on a viewing area of an interior surface of the faceplate panel by an electrophotographic screening process. The screen 22 comprises a multiplicity of different color-emitting phosphor elements. A light absorbing matrix 23 has a first portion that includes a multiplicity of openings therein overlying the viewing area of the faceplate panel, and a second portion providing an imperforate border 123 extending beyond the viewing area. The phosphor elements are disposed within the openings in the matrix. A color selection electrode 25 is mounted within the faceplate panel 12, in proximity to the screen 22. An electron gun 26 is centrally disposed within the neck 14 for generating and directing a plurality of electron beams 28 toward the screen 22.

Abstract: A fluorescent layer formation process which comprises dispersing particles of a fluorescent substance and particles of a (meth)acrylic resin as a binder or particles of the fluorescent substance coated with the (meth)acrylic resin in a medium incapable of dissolving the resin therein to prepare a fluorescent paste; applying the fluorescent paste on a fluorescent layer formation surface to form a paste layer; and baking the paste layer at such a temperature that the resin is substantially decomposed or burnt out, thereby to form a fluorescent layer.

Abstract: A color image receiving tube comprising three color (red, green and blue) phosphor screens on an inner surface of a face-plate; wherein at least two of said three color phosphor screens are coated with pigments; and wherein said three color phosphor screens have a total reflective brightness less than 70% that of three color phosphor screens with no pigment coating. According to the above-mentioned constitution, a color image receiving tube having a higher emisson brightness and contrast is achieved as compared to a color image receiving tube having the same reflective brightness, where the reflective brightness is obtained by lowering the light transmittance of its face-plate.

Abstract: A class of high efficiency (e.g., .gtoreq.20%) materials for use as display pixels to replace conventional phosphors in television, monitor, and flat panel displays. The materials are comprised of nanocrystals such as CdS.sub.x Se.sub.1-x, CuCl, GaN, CdTe.sub.x S.sub.1-x, ZnTe, ZnSe, ZnS, or porous Si or Ge alloys which may or may not contain a luminescent center. The nanocrystals may be doped with a luminescent center such as Mn.sup.2+ or a transition metal. The nanocrystals have passivated surfaces to provide high quantum efficiency. The nanocrystals have all dimensions comparable to the exciton radius (e.g., a size in the range of approximately 1 nm to approximately 10 nm). A quantum dot nanocrystal display phosphor that has a size selected for shifting an emission wavelength of a constituent semiconductor material from a characteristic wavelength observed in the bulk to a different wavelength.

Abstract: A projection television device includes a projection cathode-ray tube for red (1a), a projection cathode-ray tube for green (1b) and a projection cathode-ray tube for blue (1c) which are provided with phosphor layers (5a, 5b and 5c), respectively, each having a thickness which varies continuously so that it may be thick at the center portion and may be thinner at the peripheral portion. Having the above configuration, the projection television device makes it possible to suppress the loss in resolution and luminance at the peripheral portion of the image projected on the screen, thereby ensuring uniform resolution and luminance of the image. Thus, it becomes possible to enhance the quality of the image produced on the screen.

Abstract: On manufacturing a low voltage electron beam excitation phosphor display apparatus (10) which includes an anode (6) having a principal surface and enclosed in a vacuum chamber (1, 2, and 3), a phosphor film (7) formed on the principal surface, and a cathode (9) enclosed in the vacuum chamber opposite to the phosphor film, a phosphor is prepared which consists essentially of an oxisulfide and an oxide which is inevitably formed on a surface of the oxisulfide on preparing the phosphor. The oxisulfide is represented by Ln.sub.2 O.sub.2 S:R, where Ln is at least one selected from a group consisting of Gd, La, Y, and Lu and where R is a rare-earth element. The oxide is removed from the phosphor to produce an oxide-removed phosphor. A pasts comprising a mixture of the oxide-removed phosphor, a conductive material, and an autolytic type binder is coated on the principal surface of the anode which is formed on an insulating substrate (1) constituting the vacuum chamber.

Abstract: The present invention relates to a process for manufacture of color cathode-ray tube for preventing the deterioration of color purity of red phosphor while enhancing the brightness and the contrast of color cathode-ray tube, which comprises steps of forming a black matrix film corresponding to 3 colors of green(G), blue(B) and red(R) onto the panel glass by using 0.067-0.075 g atom (content relative to 1 mol of Y.sub.2 O.sub.3) of europium(Eu) as an activator for red phosphor; forming a 3 color fluorescent film onto said black matrix film, wherein said 3 color fluorescent film consists of green phosphor, red phosphor to which predetermined amount of red pigment having 50-70% of reflectance has been adhered, and blue phosphor to which predetermined amount of blue pigment having 50-65% of reflectance has been adhered; coating an organic film on the 3 color fluorescent film; forming a metal reflective film thereon; and thermally decomposing the organic film at high temperature to obtain a fluorescent plane.

Abstract: A cathode-ray tube includes a phosphor screen having a tricolor phosphor layer composed of a red phosphor, a green phosphor of ZnS:Cu, Al activated with Ni, Fe, or Co, and a blue phosphor of ZnS:Ag activated with Ni, Fe, or Co. The green phosphor and the blue phosphor have a decay intensity of at most 0.5% upon elapse of 8 milliseconds after excitation is removed therefrom. The green phosphor of ZnS:Cu, Al activated with Ni and the blue phosphor of ZnS:Ag activated with Ni have their afterglow characteristics substantially equalized to the afterglow characteristics of the red phosphor of Y.sub.2 O.sub.2 S:Eu.

Abstract: A display (300, 400) includes a face plate (40, 60) having an inner surface, a back plate (44, 64) having an inner surface opposing the inner surface of the face plate (40, 60), an electron source (48, 68) opposing the inner surface of the face plate (40, 60), and a phosphor (49, 72, 70) disposed on the face plate (40, 60). The phosphor (49, 72, 70) includes an electron-excitable UV-emitting material (52, 72) and a UV-excitable light-emitting phosphor (50, 70). The UV-excitable light-emitting phosphor (50, 70) is disposed to receive UV radiation emitted by the electron-excitable UV-emitting material (52, 72). The electron-excitable UV-emitting material (52, 72) includes a sol-gel product formed using sol-gel techniques.

Abstract: Disclosed is a phosphor suitable for use in a cathode-ray tube, a fluorescent lamp, a radiation intensifying screen, which comprises transparent spherical particles having an average particle size of 0.5 to 20 .mu.m and a ratio of the major diameter to the minor diameter of individual particles in the range of 1.0 to 1.5, and ultrafine particles having a diameter of 0.2 .mu.m less in an amount of 5 wt % or less.

Abstract: A phosphor film structure comprising a substrate and a phosphor film formed on the substrate, wherein the phosphor film comprises ultrafine phosphor particles having an average diameter of 200 nm or less, and obtained by heating a phosphor material to vaporize and rapidly quenching to solidify, and a haze of the phosphor film to a luminous flux of 380-760 nm in wavelength is 50% or less.

Abstract: The brightness of a color CRT with a pigmented phosphor screen is improved by providing a composite layered screen in which a first layer of the composite layer is a relatively thin, heavily pigmented layer and a second is non-pigmented.

Abstract: A color display screen having a coating which comprises at least a greend an/or a red phosphor as well as at least a pigment having the following composition:Ga.sub.a In.sub.b Zn.sub.c Al.sub.d O.sub.n S.sub.m Se.sub.o Te.sub.pwherein0.05<a<1.95 0.0.ltoreq.n<0.30.05<b<1.95 2.1<m.ltoreq.30.00.ltoreq.c<0.09 0.0.ltoreq.o<0.30.00.ltoreq.d<0.2 0.0.ltoreq.p<0.3and n+m+o+p=3 and a+b+2/3c+d=2, yields a high-contrast and low-reflection picture, because the pigmentation in accordance with the invention is self-luminescent and its solid-solution properties enable its absorption properties to be accurately adapted to the emission spectrum of the phosphor. The solid solutions having the composition Ga.sub.a In.sub.b Zn.sub.c Al.sub.d O.sub.n S.sub.m Se.sub.o Te.sub.p are characterized by steep absorption edges in the yellow-orange spectral range and by a high absorptivity. This permits thin pigment-containing layers and small quantities of pigment to be used.

Abstract: A phosphor composition selected from a range of phosphor compositions is provided for discharging spent electrons from a display screen of a luminescent display. The selected phosphor composition is a mixture of phosphor species, including a dielectric phosphor species capable of emitting visible green, blue or red light when subjected to excitation electrons at a relatively high voltage and a conductive phosphor species capable of emitting visible green, blue or red light when subjected to energized excitation electrons at a relatively low voltage. The display screen of the luminescent display is coated with the selected phosphor composition to form a cathodoluminescent layer on the screen. The cathodoluminescent layer is then selectively subjected to excitation electrons having a voltage within a predetermined broad range. The excitation electrons impart their energy to the phosphor composition causing it to emit visible green, blue or red light, thereby creating an image on the screen.

Abstract: A field emission type fluorescent display device capable of carrying out luminous display with increased reliability at an anode voltage 200V to 1000V and providing a desired luminous color by means of a filter. The fluorescent display device includes a luminous display section consisting of three display elements. The display elements include filters of red, green and blue colors on which light-permeable anode conductors are deposited, respectively. Then, the anode conductors have phosphors of the same colors as the filters deposited thereon, respectively. The blue phosphor is made of ZnO:Zn substantially containing a blue color component. Thus, a combination of the blue filter and phosphor provides light of a blue color with increased efficiency.

Abstract: An europium activated yttrium oxysulfide fluorescencer composition for color cathode-ray tube is disclosed, wherein a first red fluorescencer with predetermined particle size and a second red fluorescencer with smaller particle size are mixed and said first fluorescencer and second fluorescencer comprises respectively 0.07-0.08 g atomic weight of europium as an activator relative to 1 mole of yttrium oxysulfide as a mother body.

Abstract: The invention relates to a luminescent zeolite of the Faujasite type containing Ce.sup.3+ ions. Such a zeolite can for instance be used in the luminescent screen of a low pressure mercury discharge lamp for use in photochemical processes. According to the invention the zeolite further contains cations S.sup.n+, wherein n.gtoreq.2 and the sum of the amount of Ce.sup.3+ ions and the amount of cations S.sup.n+ per unit cell of the zeolite is at least 16. The zeolite exhibits a high quantum efficiency for converting UV radiation of 254 nm into radiation having an emission maximum between 315 and 400 nm, even in case the Ce.sup.3+ ion content is relatively low.

Abstract: For the manufacture of a color screen for a cathode ray tube a process is described which uses a single photolithographic mask for defining multiple patterns, so that said single mask may be used for determining the different areas where several different phosphor layers will be located. Masks used for conventional photolithographic processes normally comprise a pattern of regions that are either fully transparent or fully opaque to the radiation used for exposing the resist. The mask used as part of the present invention includes regions that are neither fully transparent nor fully opaque, having, instead, a grey scale of optical densities. Through careful control of both exposure and development time, selected parts of a layer of a positive photoresist, that were exposed through successively denser regions of the mask, can be successively removed.

Abstract: In an electroluminescent device wherein a first electrode, a first insulating layer, a luminescent layer, a second insulating layer, and a second electrode are laminated in that order on a transparent electrode, the luminescent layer is made of ZnS as a host material and Tb, O, F, and Cl as additives Cl/Tb and Cl/F atomic ratios in the luminescent layer are each between 0.002 and 0.2 inclusively, and Cl concentration in the luminescent layer is between 0.002 at % and 0.2 at % inclusively. By adding a predetermined amount of Cl as mentioned above, the luminescent efficiency and luminescent brightness of the electroluminescent device can be improved.

Abstract: A color display screen comprising a coating which contains at least a green and/or a red phosphor and at least a pigment having the composition Zn.sub.3-3x In.sub.2xy Ga.sub.2x-2xy S.sub.3, wherein 0.2<x<0.97 and 0.1<y.ltoreq.1.0, yields a high-contrast and low-reflection picture, because the solid-solution properties of the pigmentation in accordance with the invention enable its absorption properties to be accurately adapted to the emission spectrum of the phosphor. The solid solutions having the above-mentioned composition are characterized by steep absorption edges in the yellow-orange spectral range and by a high absorptivity. This permits thin pigment-containing layers and small quantities of pigment to be used.

Abstract: The invention relates to a display screen comprising a phosphor composition of a sulphide and/or selenide-containing phosphor which is provided with a coating which comprises one or more catena-polyphosphates of one or more alkaline earth metals, zinc, cadmium and/or manganese. In such a display screen, in particular a low-energy cathode ray display screen, the advantages of the efficient sulphide or selenide-containing phosphors can be used and said display screen remains bright and rich in contrast for a long period of time because the coating acts as a stabilizing protective coating which limits the corrosion processes in sulphide and/or selenide-containing phosphors induced by low-energy radiation.

Abstract: To provide a stable phosphor with a high brightness and little luminous degradation, a phosphor comprises yttrium, aluminum (a part or the whole of aluminum may be replaced with gallium), and oxygen as basic constituting elements, Tb or Ce as an activator, and the garnet structure as a crystal structure and in the curve 1-1 showing the temperature dependency of the thermoluminescence intensity, the integrated intensity of the thermoluminescence peak in the temperature range from 300K to 700K is made smaller than the integrated intensity of the thermoluminescence peak in the temperature range of less than 300K.

Abstract: A screen structure of a cathode-ray tube includes color filters of three R, G and B colors arranged individually on the inside of the panel, black matrixes between each color filter, a complex phosphor which mixes phosphors of the R, G and B three primary colors in equal proportion on the front side, black matrixes and color filters being spread on the front side, to maintain the most suitable repeatability of images, namely the most suitable color purity and brightness character, demonstrating an easy formation of the screen.

Abstract: A mixed green-emitting phosphorus manufactured by mixing InBO.sub.3 :Tb and one selected from ZnS:Cu,Au,Al and ZnS:Cu,Al, optionally with Zn.sub.2 SiO.sub.4 :Mn. A cathode ray tube adopting the mixed green-emitting phosphor not only has good luminance and color purity, but also enhanced afterglow and luminosity characteristics.

Abstract: The invention provides methods, compositions, and apparatus for performing sensitive detection of analytes, such as biological macromolecules and other analytes, by labeling a probe molecule with an up-converting label. The up-converting label absorbs radiation from an illumination source and emits radiation at one or more higher frequencies, providing enhanced signal-to-noise ratio and the essential elimination of background sample autofluorescence. The methods, compositions, and apparatus are suitable for the sensitive detection of multiple analytes and for various clinical and environmental sampling techniques.

Abstract: The invention relates to a display screen comprising a phosphor composition of a sulphide and/or selenide-containing phosphor which is provided with a coating which is composed of germanium disulphide and/or germanium diselenide. In such a display screen, in particular a low-energy cathode ray display screen, the advantages of the efficient sulphide or selenide-containing phosphors can be used and said display screen remains bright and rich in contrast for a long period of time because the coating, which is composed of germanium disulphide and/or germanium diselenide, surprisingly acts as a stabilizing protective coating which limits the corrosion processes in sulphide and/or selenide-containing phosphors induced by low-energy radiation.

Abstract: The present invention relates to a novel cost efficient luminescent composition comprising particles of a core material which have been coated with a luminescent material that is distributed in the form of a chemically homogeneous layer. The average diameter of the core particle is in the range of from about 0.5 to 20 microns, and the coating corresponds to between about 2 and 30 wt % of the total composition. One aspect the invention relates to a process for preparing the composition which comprises decomposing chelated metal luminescent precursors in solution at a relatively high pH while in the presence of dispersed core particles, thereby coating the core particles with hydrous metal oxides, recovering the coated particles, washing the coated particles substantially free from soluble species, drying and calcining. In another aspect, a hydrous oxide coating is converted to a sulfide coating by treating the hydrous coating with a source of active sulfur.

Abstract: A multi-stage process for preparing a phosphor product includes the stages of selecting precursors of a dopant and a host lattice as the phosphor starting materials, grinding the starting materials in an initial grinding stage for an initial grinding time period to produce an initial ground material having a smaller particle size distribution than the starting materials, firing the initial ground material in an initial firing stage at an initial firing temperature for an initial firing time period to produce an initial fired material, grinding the initial fired material in an intermediate grinding stage for an intermediate grinding time period to produce an intermediate ground material having a smaller particle size than the initial fired material, wherein the intermediate grinding time period is substantially less than the initial grinding time period, firing the intermediate ground material in an intermediate firing stage at an intermediate firing temperature for an intermediate firing time to produce an in

Abstract: A process is provided for manufacturing high-purity phosphors having utility in field emission displays. The high-purity phosphor is a host lattice infiltrated by a dopant that activates luminescent properties therein. The lattice and dopant are initially milled together to reduce their average particle size while simultaneously achieving complete mixing between the lattice and the dopant. The resulting mixture is maintained free of a flux or substantially any other treatment agent capable of contaminating the phosphor and placed in a heating vessel formed from a substantially impervious contaminant-free material. The mixture is heated to a high temperature effectuating thorough infiltration of the dopant into the lattice structure. The use of an impervious contaminant-free heating vessel and the exclusion of flux or other treatment agents from the mixture avoids undesirable contamination and undue particle size growth of the phosphor product during the manufacture thereof.

Abstract: A green-emitting phosphor of Tb-activated oxide, which is represented by the compositional formula:(Y.sub.l-x-y-z Tb.sub.x Yb.sub.yD.sub.z).sub.3 (Al.sub.l-w Ga.sub.w).sub.5 O.sub.12wherein D is at least one element selected from the group consisting of Sc and La, and x, y, z and w are numbers satisfying the following conditions:1.times.10.sup.-2 .ltoreq.x.ltoreq.2.times.10.sup.-11.times.10.sup.-6 .ltoreq.y.ltoreq.2.times.10.sup.-21.times.10.sup.-4 .ltoreq.z.ltoreq.5.times.10.sup.-10.ltoreq.w.ltoreq.1,and which contains from 1.times.10.sup.-5 to 1.times.10.sup.-2 gram atom of barium element per mol of the phosphor and is capable of emitting a color within the following range by CIE chromaticity coordinates:0.325.ltoreq.X.ltoreq.0.3600.540.ltoreq.Y.ltoreq.0.625.

Abstract: The invention relates to a luminescent screen and to a low pressure mercury discharge lamp comprising such a luminescent screen. According to the invention the luminescent screen comprises a zeolite containing trivalent Ce. The luminescent screen exhibits a large quantum efficiency for converting UV radiation of 254 nm into radiation having an emission maximum at approximately 346 nm.