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:
Dec. 28, 2010
Filed:
Sep. 18, 2008
Marcus J. H. Kessels, Susteren, NL;
Willem Sillevis Smitt, San Jose, CA (US);
Gerd Mueller, San Jose, CA (US);
Serge Bierhuizen, Santa Rosa, CA (US);
Marcus J. H. Kessels, Susteren, NL;
Willem Sillevis Smitt, San Jose, CA (US);
Gerd Mueller, San Jose, CA (US);
Serge Bierhuizen, Santa Rosa, CA (US);
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Philips Lumileds Lighting Company, LLC, San Jose, CA (US);
Abstract
A backlight for a color LCD includes white light LEDs formed using a blue LED die with a layer of red and green phosphors over it. The attenuation by the LCD layers of the blue light component of the white light is typically greater as the blue wavelength becomes shorter. In order to achieve a uniform blue color component across the surface of an LCD screen and achieve uniform light output from one LCD to another, the blue light leakage of the phosphor layer is tailored to the dominant or peak wavelength of the blue LED die. Therefore, the white points of the various white light LEDs in a backlight should not match when blue LED dies having different dominant or peak wavelengths are used in the backlight. The different leakage amounts through the tailored phosphor layers offset the attenuation vs. wavelength of the LCD layers.