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:
Apr. 30, 2013
Filed:
Jan. 31, 2012
Chung Hoon Lee, Ansan-si, KR;
Walter Tews, Greifswald, DE;
Gundula Roth, Levenhagen, DE;
Stefan Tews, Greifswald, DE;
Chung Hoon Lee, Ansan-si, KR;
Walter Tews, Greifswald, DE;
Gundula Roth, Levenhagen, DE;
Stefan Tews, Greifswald, DE;
Seoul Semiconductor Co., Ltd., Seoul, KR;
Abstract
Disclosed is a light emitting device employing non-stoichiometric tetragonal Alkaline Earth Silicate phosphors. The light emitting device comprises a light emitting diode emitting light of ultraviolet or visible light, and non-stoichiometric luminescent material disposed around the light emitting diode. The luminescent material adsorbs at least a portion of the light emitted from the light emitting diode and emits light having a different wavelength from the absorbed light. The non-stoichiometric luminescent material has tetragonal crystal structure, and contains more silicon in the crystal lattice than that in the crystal lattice of silicate phosphors having stoichiometric crystal structure. The luminescent material is represented as the formula (BaSrCaCu)(Zn,Mg,Mn)SiO:Eu. Light emitting devices having improved temperature and humidity stability can be provided by employing the non-stoichiometric tetragonal Alkaline Earth Silicate phosphors.