Gte Laboratories Incorporated

Gte Products Corporation

Osram Sylvania Inc.

Thomas E Peters

Romano G Pappalardo

Roger B Hunt, Jr

James R McColl

A Gary Sigai

Anthony F Kasenga

Han J Kim

John C Gustafson

Jean M Evans

Harold L Rothwell, Jr

William J Miniscalco

Kailash C Mishra

Harold Rothwell, Jr

Boon Wong

Baldassare Di Bartolo

Karen Lee

Alexandre Vetrovs

John Collins

David Snee

A phosphor coating for gas discharge lamps is provided. The phosphor coating contains a nano-size phosphor which promotes adherence of the primary phosphor to the glass envelope. The phosphor coating is applied to the interior surface of the gas discharge lamp using an aqueous suspension containing the primary phosphor, the nano-size phosphor, and an organic binder.

Phosphor coating for gas discharge lamps and lamp containing same

A neon gas discharge lamp is provided which produces an acceptable amber color emission for automotive applications. The red emission from the neon discharge when the lamp is operated in a pulsed mode is combined with a green emission from a substituted Y.sub.3 Al.sub.15 O.sub.12 :Ce phosphor coated on the interior surface of the lamp. The resulting amber emission meets both SAE and ECE amber color requirements. In particular, phosphor has the general formula:

Neon discharge lamp for generating amber light

A host acting as an optical emitter and a process of making the same for the .sup..about. 1.3 .mu.m to .sup..about. 1.55 .mu.m spectral region utilized in optical communications is disclosed. The host is Cr-activated willemite (Zn.sub.2 SiO.sub.4). Efficient band-emission at room temperature, with peak at 1.42 .mu.m, is observed on exiting the material in the near infrared, typically at 730 nm and 829 nm.

Optical emitter for amplification and process for making same

A new and improved method of treating a manganese activated zinc silicate phosphor is described. The method comprises heating a manganese activated zinc silicate phosphor powder having cations consisting essentially of zinc, silicon, manganese, and tungsten and having a 350 nm reflectance less than 80% and a 275 nm reflectance greater than 13.5% to a temperature of about 1225.degree. C. in air. The phosphor powder is then cooled to room temperature and wet milled in an acid solution. The phosphor powder is then separated from the acid solution washed in water and dried to form a dry phosphor powder having a 350 nm reflectance equal to or greater than 80% and a 275 nm reflectance equal to or less than 13.5%.

Method for improving a manganese activated zinc silicate phosphor

The lumen maintenance of fluorescent lamps containing yttrium vanadate phosphors is markedly improved by the presence of a protective oxide layer for the phosphor. The protective oxide layer is produced by evaporating aluminum isopropoxide, in a vacuum, over phorphor particles forming a continuous aluminum isopropoxide over the phosphor particles. The isopropoxide coating is subsequently oxidized by lehring the phosphor at a temperature from about 500.degree. C. to 625.degree. C. forming an alumina coating on the phosphor particles.

Method of coating yttrium vanadate phosphors with Al.sub.2 O.sub.3

A method for producing manganese activated zinc silicate phosphor wherein the individual phosphor particles are surrounded with a non-particulate, conformal aluminum oxide coating is disclosed. The method comprises dry blending a mixture of components consisting essentially of zinc oxide, silicic acid, a source of manganese, ammonium chloride, ammonium fluoride, tungstic oxide, and silica, wherein the Zn+Mn/Si mole ratio is from about 1.95 to about 2.02, wherein the silica is colloidal and has a surface area of from about 50 to about 410 m.sup.2 per gram, and wherein the colloidal silica makes up from about 0.01% to about 1.0% by weight of the mixture; firing the resulting dry blend of components in a nitrogen atmosphere at a temperature of from about 1200.degree. C. to about 1300.degree. C. for a sufficient time to produce the phosphor; milling the resulting phosphor for a period of time of from about 60 minutes to about 120 minutes; firing the resulting milled phosphor in air at a temperature of from about 1175.degree. C. to about 1275.degree. C. for a sufficient time to diffuse the tungsten and manganese to the surfaces of the phosphor particles; applying a non-particulate, conformal aluminum oxide coating to the outer surface of individual particles of the phosphor while the phosphor particles are suspended in a fluid bed having a midpoint temperature between 400.degree. and 480.degree. C., the aluminum oxide coating being formed by a chemical vapor deposition reaction involving oxidation of trimethyl aluminum; and annealing the aluminum oxide coated phosphor for a period of time from 4-16 hours at a temperature between 750.degree. and 800.degree. C.

Firing and milling method for producing a manganese activated zinc

A fluorescent lamp containing a Y.sub.2 O.sub.3 or Al.sub.2 O.sub.3 coating on a layer of yttrium vanadate phosphor and a method of coating the layer of the yttrium vanadate phosphor with a continuous protective coating of Y.sub.2 O.sub.3 or Al.sub.2 O.sub.3 is described. The method comprises applying a coating of a metal, such as yttrium or aluminum, on the yttrium vanadate phosphor then lehring the metallic coating at about 500.degree. C. to about 625.degree. C. to form a continuous protective coating of Y.sub.2 O.sub.3 or Al.sub.2 O.sub.3 overlaying the layer of phosphor.

A method of coating a layer of an yttrium vanadate phosphor contained in

A new and improved manganese activated zinc silicate phosphor is described. The phosphor has cations consisting essentially of zinc, silicon, manganese, and tungsten. The phosphor has an absolute reflectance less than or equal to 13.5% at 275 nm, an absolute reflectance equal to or greater than 80% at 350 nm, and a surface area from about 0.3 m.sup.2 /gm to about 0.4 m.sup.2 gm.

Manganese activated zinc silicate phosphor

A manganese activated zinc silicate phosphor and method for producing same is disclosed which comprises dry blending a mixture of components consisting essentially of zinc oxide, silicic acid, a source of manganese, ammonium chloride, ammonium fluoride, tungstic oxide and silica wherein the Zn+Mn/Si mole ratio is from about 1.95 to about 2.02, wherein the silica is colloidal and has a surface area of from about 50 to about 410 m.sup.2 /g, and wherein the colloidal silica makes up from about 0.01% to about 1.0% by weight, firing the blend in a nitrogen atmosphere at a temperature of from about 1200.degree. C. to about 1300.degree. C. for a sufficient time to produce the phosphor, and firing the phosphor in air at a temperature of from about 1175.degree. C. to about 1275.degree. C. for a sufficient time to diffuse the tungsten and manganese to the surfaces of the phosphor particles. Between the firing steps, the phosphor can be milled for from about 60 to 120 minutes to increase luminescence. The phosphor can be coated with a continuous coating of aluminum oxide and annealed to improve maintenance of the phosphor. A fluorescent lamp incorporating the phosphor is also disclosed.

A method for preventing the hydration/solubilization of the protective oxide coating of a phosphor is described. The method involves coating of the oxide coated phosphor particles with a continuous hydrophobic coating. After the phosphor particles are coated with the continuous hydrophobic coating and the continuous hydrophobic coating cured, they are added to a water-based suspension and subsequently processed into a lamp.

Method of treating a coated phosphor

A method for eliminating carbonaceous contaminants and preventing the hydration/solubilization of the oxide coating of a phosphor is described. The method involves the annealing of the oxide coated phosphor at a temperature and for a period sufficient to preclude adversely affecting the protective oxide coating on the phosphor during subsequent water-based suspension processing without detrimentally altering the phosphor. After annealing the phosphor is cooled and then added to a water-based suspension. The optimum conditions for annealing a manganese activated zinc silicate phosphor or a calcium halophosphate phosphor having a protective aluminum oxide coating are the combination of a temperature between about 700.degree. C. and about 850.degree. C. and for a period of time from about 15 minutes to about 20 hours.

Pre-water-based suspension phosphor treatment process

The present invention is directed to luminescent materials having the general formula:

Process for preparing high-brightness yellow-emitting triboluminescent

The present invention is directed to phosphors exhibiting efficient, narrow band UV emission, with peak emission at 330 nm (from excitation at 254). These phosphors are cerium-activated calcium pyrophosphate (beta-phase) of nominal formulation

Efficient UV-emitting phosphors based on cerium-activated calcium

An efficient green emitting phosphor results from the coactivation of yttrium fluoride with gadolinium and erbium. The excitation energy absorbed by the Gd.sup.3+ centers is transferred non-radiatively to minority Er.sup.3+ centers, whose emission produces green light when excited by 275 nanometer or 378 nanometer radiation.

Green emitting phosphor

Yellow emitting fluorescent lamp phosphor compositions comprise cerium and manganese activated alkali-earth fluoroapatite compositions containing sodium having the approximate formula

Growing community of inventors

Chelmsford, MA, United States of America

Thomas E Peters