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:
Oct. 13, 2015
Filed:
Mar. 22, 2013
Koninklijke Philips N.v., Eindhoven, NL;
Ties Van Bommel, Horst, NL;
Rifat Ata Mustafa Hikmet, Eindhoven, NL;
René Theodorus Wegh, Veldhoven, NL;
Martinus Petrus Joseph Peeters, Weert, NL;
Gerardus Wilhelmus Gerbe Van Dreumel, Nijmegen, NL;
Lars Christian Casper, Den Bosch, NL;
KONINKLIJKE PHILIPS N.V., Eindhoven, NL;
Abstract
The invention provides a lighting device () comprising a light source () and luminescent materials (). The luminescent materials () comprise a first organic luminescent material () and a second organic luminescent material (), the light source () together with the luminescent materials () being configured to generate white lighting device light () during operation. The first organic luminescent material () degrades with time at a first degradation rate and the second organic luminescent material () degrades with time at a second degradation rate, wherein the first degradation rate is larger than the second degradation rate. The first organic luminescent material is configured in a first layer () and the second organic luminescent material is configured in a second layer (). The first layer and/or the second layer is further configured to at least partly compensate for the difference in the first degradation rate and the second degradation rate in order to maintain the lighting device light () substantially white during operation time of the lighting device ().