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:
Jan. 27, 2009
Filed:
May. 28, 2003
Frank Jermann, München, DE;
Markus Richter, Neutraubling, DE;
Wolfgang Rossner, Holzkirchen, DE;
Martin Zachau, Geltendorf, DE;
Frank Jermann, München, DE;
Markus Richter, Neutraubling, DE;
Wolfgang Rossner, Holzkirchen, DE;
Martin Zachau, Geltendorf, DE;
Osram Opto Semiconductors GmbH, Regensburg, DE;
Patent-Treuhand-Gesselschaft für elektrische Glühlampen mbH, Munich, DE;
Abstract
A luminescent powder () with luminescent particles () having an average luminescent-particle size () selected from the range of from 0.1 μm inclusive to 5.0 μm inclusive. The luminescent particles comprise primary particles () having an average primary-particle size (5) selected from the range of from 0.1 μm inclusive to 1.0 μm inclusive. The primary particles which, for example, consist of a cerium-doped yttrium-aluminum garnet (YAlO), are agglomerated to form the luminescent particles. A method for producing the luminescent powder has the following steps: a) preparing at least one precursor of the primary particles, b) producing the primary particles from the precursor of the primary particles, and c) forming the luminescent particles of the luminescent powder from the primary particles. The precursor for YAlOis, for example, a powder mixture of hydroxides. In order to prepare the precursor, the hydroxides are precipitated from a sulfuric-acid solution containing metal by dropwise addition of a basic ammonia solution. The precipitate is dried and subsequently calcined, so that the primary particles are formed and simultaneously cluster together to form the luminescent particles of the luminescent powder.