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. 14, 2015
Filed:
Jun. 10, 2014
Cree, Inc., Durham, NC (US);
Antony P. van de Ven, Hong Kong, CN;
Jason E. Taylor, Cary, NC (US);
Paul K. Pickard, Morrisville, NC (US);
Gauss Ho Ching So, Kowloon, HK;
Heidi M. Dieringer, Cary, NC (US);
Andrew Dummer, Chapel Hill, NC (US);
Cree, Inc., Durham, NC (US);
Abstract
Semiconductor light emitting devices are provided that include a first string of light emitting diodes ('LED') that emit unsaturated light having a color point that is within at least eight MacAdam ellipses of one or more points within a first blue-shifted-yellow region on the 1931 CIE Chromaticity Diagram, a second string of LEDs that emit unsaturated light having color point that is within at least eight MacAdam ellipses from one or more points within a second blue-shifted-green region on the 1931 CIE Chromaticity Diagram, and a third light source that emits radiation having a dominant wavelength between 600 and 720 nm. A drive circuit is provided that is configured to supply a first drive current to the first string of LEDs, a second drive current to the second string of LEDs and a third drive current to the third string of LEDs, wherein at least two of the first, second and third drive currents are independently controllable.