Osram Sylvania Inc.

Global Tungsten & Powders Corp.

Chung-nin Chau

Chen-Wen Fan

Gregory A Marking

Roger B Hunt, Jr

Thomas M Snyder

Shellie K Northrop

Paul W Salvi

Chen Wen Fan

Thomas Snyder

An electroluminescent lamp having a high color rendering index (CRI) can be made using a phosphor blend comprising a mixture of an electroluminescent phosphor and an europium-activated alkaline earth silicon nitride phosphor, wherein the electroluminescent phosphor is selected from a blue-emitting electroluminescent phosphor, a blue-green-emitting electroluminescent phosphor, or a combination thereof. Preferably, the lamp exhibits a CRI of at least about 75, and, more preferably, at least about 80. A preferred blend contains from about 10% to about 20% by weight of the europium-activated alkaline earth silicon nitride phosphor.

High CRI electroluminescent lamp

Blue-emitting phosphors for use with plasma display panels (PDP) or other vacuum ultraviolet-excited (VUV) devices are provided. These blue-emitting phosphors and mixtures thereof include at least a europium-activated calcium-substituted barium hexa-aluminate (CBAL) phosphor. Preferably, the CBAL phosphor has a composition which may be represented by the formula: BaCaEuAlO, wherein 0&#x3c;x&#x3c;0.25 and 0.01&#x3c;y&#x3c;0.20. These blue-emitting phosphors exhibit improved degradation characteristics, including reduced color shift and increased intensity maintenance, under conditions found in VUV-excited devices.

VUV-excited device with blue-emitting phosphor

A lamp envelope is provided with an alumina layer and a multilayer phosphor coating on the alumina layer. The phosphor coating includes a top phosphor layer with a first weight percent of rare earth activators and a middle phosphor layer with a second weight percent of rare earth activators. The second weight percent is less than the first weight percent so that a total amount of the activators in the coating is reduced while maintaining a required lamp brightness and color rendering index (CRI). Preferably, the second weight percent is about 50-60% of the first weight percent and the middle layer is about 30-50% of a total weight of the coating so that a total weight of the activators in the coating is no more than about 80% of a weight of the activators in the coating if the first and second weight percents were the same.

Lamp with multi-layer phosphor coating

A red-emitting phosphor blend is provided which comprises a mixture of a first red-emitting phosphor having a general formula of (Y Gd Eu ) O wherein 0&lE;x&lE;0.9 and 0.02&lE;y&lE;0.4 and a second red-emitting phosphor having a general formula of (Y Gd EU ) BO wherein 0&lE;a&lE;1 and 0.02&lE;b&lE;0.1, the second red-emitting phosphor comprising from 10 to 40% by weight of the blend.

Red-emitting phosphor blend for plasma display panels

High brightness green-emitting phosphor

Growing community of inventors

Athens, PA, United States of America

Chung-nin Chau