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. 09, 2012
Filed:
Jun. 24, 2009
Steven C. Allen, Beverly, MA (US);
Richard S. Speer, Concord, MA (US);
Steven C. Allen, Beverly, MA (US);
Richard S. Speer, Concord, MA (US);
OSRAM SYLVANIA Inc., Danvers, MA (US);
Abstract
A light emitting diode (LED) lamp includes a base with one or more LED chips, an internal cover over the LED chips, where the cover is a translucent ceramic whose thermal conductivity is greater than glass, where the cover has an interior surface separated from the LED chips by a gap, and where an exterior surface of the cover is coated with a phosphor. The ceramic cover preferably has a bulk thermal conductivity of at least 5 W/(m·K), such as polycrystalline alumina. The LED chips preferably are blue LEDs and the phosphor is selected so that the lamp emits white light. In the method of making the lamp, the phosphor may be applied to the exterior surface of the cover as a preformed sheet or in a coating.