The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 02, 1991
Filed:
Mar. 22, 1989
Tungsram Reszvenytarsasag (Tungsram RT), Budapest, HU;
Abstract
In a luminescent material which comprises a first component for luminescing red light under influence of incident optical radiation and a second component for luminescing in the spectral range from 520 to 560 nm, the second component includes a first phase of garnet crystallization system consisted of yttrium aluminate activated by trivalent cerium and determined by the general structural formula Y.sub.3-a Ce.sub.a Al.sub.5 O.sub.12, wherein 0.0003<a<0.1, and a second phase of hexagonal crystallization system of general structural formula La.sub.b Ce.sub.1-b Al.sub.11 O.sub.18, wherein O<b<1, and the second phase is present in an amount ranging from the amounts detectable by means of X-ray diffractometry to the double amount of the first phase. In a low-pressure or high-pressure mercury vapor gas discharge lamp, comprising a hermetically sealed discharge vessel including at least two electrodes for generating a gas discharge process, an inner surface is covered by a luminescent material, comprising the two phases mentioned above, wherein the composition of the two phases is determined by the general structural formula Y.sub.3-a Ce.sub.a Al.sub.5 O.sub.12 +xLa.sub.b Ce.sub.1-b Al.sub. 11 O.sub.18, wherein O<x<2, 0.0003<a<0.1 and O<b<1 and the second phase is present in an amount ranging from the amounts detectable by means of X-ray diffractometry to the double amount of the first phase.