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:
Jan. 26, 2010
Filed:
Feb. 23, 2007
Desen Cao, Sandy, UT (US);
Zhao-hui Lin, Salt Lake City, UT (US);
Desen Cao, Sandy, UT (US);
Zhao-hui Lin, Salt Lake City, UT (US);
CAO Group, Inc., West Jordan, UT (US);
Abstract
The present invention is a non-invasive method and associated apparatus for determining the junction temperature for an LED or laser diode (collectively 'LED'). First a sample LED is placed in a heat chamber and the change of the LED's peak wavelength is recorded over time, as is the change in the temperature in the heat chamber. Since the heat chamber supplies the major component to the junction temperature, dwarfing the other components, it is a reasonable proxy for true junction temperature. The data is compiled to determine change of peak wavelength as a function of temperature and that function can then be used to determine junction temperature of similar LEDs that are installed in a system or manufactured. The invention may also be used to measure other useful data, such as power, output power changing with the junction temperature and intensity of the LED over time and may be used to estimate failure rate.