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:
Jul. 07, 2015
Filed:
May. 28, 2013
National Central University, Taoyuan County, TW;
Ching-Cherng Sun, Taoyuan County, TW;
Ching-Yi Chen, New Taipei, TW;
Hsin-Mei Wu, Kaohsiung, TW;
Cheng-Chien Chen, Yilan County, TW;
National Central University, Taoyuan County, TW;
Abstract
A light emitting device is provided to produce white light with a stable correlated color temperature and stable color coordinates. The light emitting device includes a blue LED chip and a yellow phosphor. The blue LED chip has a peak wavelength X slightly smaller than the peak wavelength Y of the phosphor such that when the light emitting device is subjected to a predetermined operating current, the phosphor decays due to thermal effect, and the LED chip has its emission spectrum red-shifted to substantially match with the excitation spectrum of the phosphor. At this time, the excitation ability of the LED chip is increased and causes an increase of yellow power output from the phosphor that substantially compensates a decrease of yellow light output caused by the phosphor.