Gte Products Corporation

Gte Laboratories Incorporated

Fred R. Taubner

Henry B. Minnier

Charles F. Chenot

A. Gary Sigai

Fred R Taubner

A Gary Sigai

Joseph A Roy

Charles F Chenot

Tadius T Sadoski

Albert K Fan

Vincent Chiola

Henry B Minnier

Richard L Doucette

Francis P Mackey

John P Gallien

Gerald B Fredrickson

A method for preparing a specific zinc orthosilicate phosphor particle having a nonparticulate, conformal aluminum oxide coating wherein all of a manganese activator is present as manganese (II) and occupies zinc (II) sites includes the steps of blending a zinc source, a manganese (II) source, a silicon source, and a tungsten source in amounts in accordance with said formula with an amount of up to about 2 weight percent NH.sub.4 Cl and up to about 0.2 weight percent NH.sub.4 F to form a relatively uniform admixture, firing the mixture in a closed container under an inert non-oxidizing atmosphere to promote retention of manganese in the plus two valance state whereby oxidation of manganese to a higher valence state is avoided and conditions promote larger particle size formation; milling and washing the phosphor in an aqueous citric acid solution to remove unreacted manganese; rinsing, drying and sieving the dried phosphor; and depositing a continuous, nonparticulate, conformal aluminum oxide coating on the dried phosphor particle.

Method for preparing zinc orthosilicate phosphor particle

An improved fluorescent lamp is disclosed. The lamp of the present invention includes an envelope containing an ionizable medium including mercury and having electrodes located within the envelope; an aluminum oxide reflector layer on the inner surface of the envelope, and a phosphor layer disposed on the reflector layer. The aluminum oxide reflector layer comprises particles of high purity aluminum oxide having an average particle size greater than 0.5 micrometer and less than or equal to about 1 micrometer and having a surface area of about 4 to 6 meter.sup.2 /gram. The aluminum oxide reflector layer preferably includes at least 95 weight percent alpha-alumina. Preferred coating weights for the reflector layer are from about 8.8 to about 11.1 milligram/square centimeter.

Aluminum oxide reflector layer for fluorescent lamps

An improved aperture fluorescent reprographic lamp is disclosed. The lamp of the present invention includes an elongated envelope containing an ionizable medium including mercury and having electrodes at each end of the envelope: a reflector layer on a major portion of the inner surface of the envelope, a phosphor layer disposed on and coextensive with the reflector layer, and a protective coating over at least the portion of the inner surface of the lamp envelope not covered with the reflector layer. The phosphor layer comprises particles of green-emitting zinc orthosilicate phosphor which are individually coated with a non-particulate, conformal aluminum oxide coating.

Reprographic aperture lamps having improved maintenance

Lumen maintenance of fluorescent lamps is improved by overcoating the phosphor layer with a coating of submicron size alumina having a weight greater than 160 micrograms per square centimeter.

Arc discharge lamp having improved lumen maintenance

A fluorescent lamp has two phosphor layers, the phosphor of the first layer being less expensive than the phosphor of the second layer. The second phosphor layer improves the lamp efficiency.

Fluorescent lamp having double phosphor layer

A fluorescent lamp has a phosphor coating on the interior surface of the lamp envelope. Dispersed throughout the coating is a melted and solidified amorphous borate-phosphate frit to improve the adhesion of the phosphor.

Fluorescent lamp containing adhesive frit in phosphor coating

A fluorescent lamp contains a blend of phosphors to provide predetermined minimum power levels of radiation at predetermined spectral bands that are used in the analysis of liquid samples placed close to the lamp.

Growing community of inventors

Danvers, MA, United States of America

Fred R Taubner