Oxygen-containing phosphor powders, methods for making phosphor powders and devices incorporating same
AssigneeSuperior MicroPowders LLC
InventorsMark J. Hampden-Smith, Toivo T. Kodas, James Caruso, Daniel J. Skamser, Quint H. Powell
Life of this patent
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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.
Claims164
A powder batch comprising oxygen-containing phosphor particles, wherein said phosphor particles have a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said particles are not larger than twice said average particle size.
A powder batch comprising ZnO phosphor particles, wherein said ZnO phosphor particles have a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said phosphor particles are not larger than twice said average particle size.
A powder batch comprising Y2O3 phosphor particles, wherein said phosphor particles have a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said particles are not larger than twice said average particle size.
A powder batch comprising Y3 Al5O12 phosphor particles, wherein said phosphor particles have a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said particles are not larger than twice said average particle size.
A powder batch comprising barium aluminate phosphor particles, wherein said phosphor particles have a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said particles are not larger than twice said average particle size.
A powder batch comprising metal silicate phosphor particles, wherein said phosphor particles have a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said particles are not larger than twice said average particle size.
A powder batch comprising oxygen-containing phosphor particles, wherein said phosphor particles have a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said particles are not larger than twice said average particle size and wherein said phosphor particles comprise at least a first coating on an outer surface thereof.
A powder batch comprising composite oxygen-containing phosphor particles, wherein said composite phosphor particles have a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said particles are smaller than twice said average particle size and wherein said phosphor particles comprise at least a first oxygen-containing phosphor compound phase and at least a second phase.
A powder batch comprising a particulate precursor to an oxygen-containing phosphor, wherein said particulate precursor has a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said particles are smaller than twice said average particle size, wherein said particulate precursor is adapted to be converted into an oxygen-containing phosphor having a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said particles are smaller than twice said average particle size.
A method for the production of oxygen-containing phosphor particles, comprising the steps of:
- a) generating an aerosol of droplets from a liquid wherein said liquid comprises a oxygen-containing phosphor precursor and wherein said droplets have a size distribution such that at least about 80 weight percent of said droplets have a size of from about 1 μm to about 5 μm;
- b) moving said droplets in a carrier gas;
- and
- c) heating said droplets to remove liquid therefrom and form oxygen-containing phosphor particles.
A method for the production of coated oxygen-containing phosphor particles, comprising the steps of:
- a) forming a liquid solution comprising a oxygen-containing phosphor precursor;
- b) generating an aerosol of droplets from said liquid solution;
- c) moving said droplets in a carrier gas;
- d) heating said droplets to remove liquid therefrom and form particles comprising a oxygen-containing phosphor;
- and
- e) coating an outer surface of said oxygen-containing phosphor particles.
A method for the production of composite oxygen-containing phosphor particles, comprising of steps of:
- a) forming a liquid solution comprising an oxygen-containing phosphor precursor and a second phase precursor;
- b) generating an aerosol of droplets from said liquid solution;
- c) moving said droplets in a carrier gas;
- and
- d) heating said droplets to remove liquid therefrom and form composite oxygen-containing phosphor particles comprising an oxygen-containing phosphor compound and a second phase.
A method for the production of an oxygen-containing phosphor powder, comprising the steps of:
- a) forming an aqueous-based solution comprising soluble precursors of an oxygen-containing phosphor;
- b) generating an aerosol of droplets from said aqueous-based solution;
- c) heating said droplets to form an intermediate compound that is capable of being post-treated to form said oxygen-containing phosphor compound;
- and
- d) treating said intermediate compound to form said oxygen-containing phosphor powder.
A display device for conveying visual graphics and information, comprising:
- a) a plurality of pixel regions comprising phosphor powder layers;
- and
- b) an excitation source adapted to stimulate said phosphor powder to emit light to be viewed by a viewer;
- wherein said phosphor powder comprises oxygen containing phosphor particles that are substantially spherical and have a weight average particle size of not greater than about 5 μm.
A flat panel display, comprising:
- a) an excitation source adapted to stimulate a phosphor;
- and
- b) a viewing panel proximate to said excitation source, comprising a transparent substrate having disposed thereon an oxygen-containing phosphor powder defining pixels, wherein said phosphor powder comprises substantially spherical particles having a weight average particle size of not greater than about 10 μm.
A field emission display, comprising:
- (a) a back plate portion comprising a plurality of electron tip emitters;
- (b) a transparent front plate portion comprising a layer of phosphor powder comprising oxygen-containing phosphor particles, wherein said phosphor particles have a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said particles are not larger than twice said average particle size.
An electroluminescent device, comprising an electrically insulative substrate, a first electrode supported on said substrate, a phosphor layer disposed over said first electrode, a second electrode disposed over said phosphor layer, and means for applying an electric field between said first and second electrodes, wherein said phosphor layer comprises phosphor powder comprising oxygen-containing phosphor particles, wherein said phosphor particles are substantially spherical and have a weight average particle size of not greater than about 5 μm
A method for securing a document, comprising the step of applying a phosphor powder to said document, wherein said phosphor powder comprises oxygen-containing phosphor particles, wherein said phosphor particles are substantially spherical and have a weight average particle size of not greater than about 5 μm.
A plasma display panel, comprising:
- a) a rear panel comprising a plurality of row electrodes;
- b) a front panel comprising a plurality of column electrodes, wherein said row electrodes and said column electrodes are in perpendicular relation to form a plurality of addressable x-y coordinates;
- c) a phosphor powder dispersed on a substrate disposed between said electrodes, wherein said phosphor powder comprises particles having a weight average particle size of not greater than about 5 μm and a particle size distribution wherein at least about 90 weight percent of said particles are not larger than twice said average particle size.
Dependencies are inferred from the claim text.