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:
Mar. 11, 2008
Filed:
Feb. 20, 2004
Wounjhang Park, Dunwoody, GA (US);
Kazuhito Yasuda, Kani-Gifu, JP;
Brent K. Wagner, Marietta, GA (US);
Christopher J. Summers, Dunwoody, GA (US);
Youngrag DO, Seoul, KR;
Hong Guen Yang, Suwon, KR;
Wounjhang Park, Dunwoody, GA (US);
Kazuhito Yasuda, Kani-Gifu, JP;
Brent K. Wagner, Marietta, GA (US);
Christopher J. Summers, Dunwoody, GA (US);
Youngrag Do, Seoul, KR;
Hong Guen Yang, Suwon, KR;
Georgia Tech Research Corporation, Atlanta, GA (US);
Samsung Display Devices Co., Ltd., Suwan, KR;
Abstract
The present invention provides surface coated phosphors useful in field emission displays and vacuum fluorescent displays. The surface coated phosphor comprises a thin coating of rare earth oxide, e.g., yttrium oxide, disposed on an uncoated phosphor such as a sulfide phosphor. The present invention further provides a process for preparing a surface coated phosphor comprising contacting the uncoated phosphor with a rare earth hydroxide gel solution to obtain a rare earth hydroxide gel coated phosphor, drying the gel coated phosphor to remove solvent residues, and heat treating the dried rare earth hydroxide gel coated phosphor. The surface coated phosphors of the present invention have improved cathodoluminescence efficiency, coulombic aging resistance, chemical, and/or oxidative stability.