Luminescent aluminoborate glass and luminescent screen provided with such a glass
AssigneeU.S. Philips Corporation
InventorsTheo J. A. Popma, Hendrik J. M. Joormann
Life of this patent
Estimating the term…
Abstract
Luminescent aluminoborate and/or aluminosilicate glass which is activated by one or more rare earth metals. The glass has a matrix comprising from 5 to 65 mol. % of one or more of the alkaline earth metal oxides BaO, SrO, CaO, ZnO and MgO, from 20 to 85 mol. % of B.sub.2 O.sub.3 and/or SiO.sub.2 and from 1 to 35 mol. % of Al.sub.2 O.sub.3. The glass contains as activator Tb.sup.3+ and/or Ce.sup.3+ in a quantity, calculated as Tb.sub.2 O.sub.3 and/or Ce.sub.2 O.sub.3, of 0.1 to 10 mol. % with respect to the matrix. The luminescent glasses have high conversion efficiencies, especially high quantum efficiencies upon UV excitation, and are preferably used in luminescent screens of, for example, discharge lamps or cathode-ray tubes.
Claims4
A luminescent aluminoborate and/or aluminosilicate glass with high quantum efficiency upon excitation by ultraviolet radiation having a matrix which consists of from 5 to 65 mol. % of at least one alkaline earth metal oxide selected from the group consisting of BaO, SrO, CaO, ZnO and MgO;
- from 20 to 85 mol. % of B.sub.2 O.sub.3 ;
- from 1 to 35 mol. % of Al.sub.2 O.sub.3 ;
- and from 0.1 to 10 mol. %, based on the matrix, of at least one activator selected from the group consisting ofTb.sup.3+ and Ce.sup.3+, calculated as Tb.sub.2 O.sub.3 and Ce.sub.2 O.sub.3.
Dependencies are inferred from the claim text.