Highly loaded fluorescent lamp

Abstract

A high-duty fluorescent lamp (10) (Fig. 1) comprises a hollow translucent glass body (12) containing a medium capable of generating UV radiation of at least several wavelengths. A plurality of phosphors are disposed on the inner surface of the glass body (12), the plurality of phosphors emitting visible radiation when exposed to UV radiation. At least one of the plurality of phosphors degrades upon prolonged exposure to one of at least one of several wavelengths of UV radiation. At least one of the plurality of phosphors degraded in quality is installed ( FIG. 12 ) near the inner surface ( 14 ) of the glass body ( 12 ) to form the first layer ( 16 ); and the remainder of the plurality of phosphors is disposed on A second layer (18) is formed on the first layer which does not undergo long-term degradation when exposed to UV radiation.

Description

[0001] This application claims priority from Provisional Patent Application No. 60 / 224,475 filed 08 / 10 / 00. technical field [0002] This invention relates to fluorescent lamps, and more particularly to high duty electrodeless fluorescent lamps. High load means that the lamp has a discharge current equal to or greater than 2 amperes. Background technique [0003] Electrodeless lamps, such as those shown in US Patent No. 5,834,905, use a hollow glass envelope containing mercury vapor and buffer gas with a phosphor coating on the inner surface of the glass body. A phosphor is typically a substantially homogeneous mixture of three materials with emission spectra in different parts of the visible spectrum blended to emit white light. In a preferred form of this lamp, the blend includes three phosphors, namely, red-emitting Y 2 o 3 :Eu 3+ , emitting green LaPO 4 : Ce 3+ , Tb 3+ and the blue-emitting BaMgAl 10 o 17 :Eu 2+ . These lamps are designed to have an extremely l...

AI Technical Summary

Problems solved by technology

The long life of these lamps has caused problems involving color shifts in the emission spectrum

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