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:
Aug. 05, 1986
Filed:
Nov. 01, 1984
Jan L van Koesveld, Eindhoven, NL;
Roelof E Schuil, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A display tube comprising in an evacuated envelope means to generate at least one electron beam which is focused on a display screen and describes a field thereon, which display screen comprises a terbium-activated blue-luminescing phosphor on a carrier, and in which the light emitted by the phosphor falls through a filter. If the energy of the emissions of the phosphor which find their origin in the .sup.5 D.sub.3 -level of terbium is at least 40% of the energy of the emissions of all terbium levels and the filter has a transmission of more than 75% at those wavelengths where the .sup.5 D.sub.3 .fwdarw..sup.7 F.sub.5 and the .sup.5 D.sub.3 .fwdarw..sup.7 F.sub.4 emissions of terbium are located and the filter has a transmission of less than 10% at those wavelengths where the .sup.5 D.sub.4 .fwdarw..sup.7 F.sub.5 and the .sup.5 D.sub.4 .fwdarw..sup.7 F.sub.4 and the .sup.5 D.sub.4 .fwdarw..sup.7 F.sub.3 emissions of terbium are located so that the color point of the filtered light is located in the range x.ltoreq. 0.200 and y.ltoreq.0.100 in the CIE color triangle, a well saturated blue picture is displayed having a satisfactorily high energy efficiency.