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:
Aug. 16, 2005
Filed:
Oct. 09, 2003
Jozef Petrus Emanuel DE Krijger, Geldrop, NL;
Armand Boudewijn Perduijn, Eindhoven, NL;
Engbert Bernard Gerard Nijhof, Eindhoven, NL;
Marcel Johannes Maria Bucks, Weert, NL;
Jozef Petrus Emanuel De Krijger, Geldrop, NL;
Armand Boudewijn Perduijn, Eindhoven, NL;
Engbert Bernard Gerard Nijhof, Eindhoven, NL;
Marcel Johannes Maria Bucks, Weert, NL;
Lumileds Lighting U.S., LLC, San Jose, CA (US);
Abstract
In a circuit arrangement for driving a LED array comprising red, green and blue LEDs, a control loop is added for limiting the duty cycles of the control signals for driving the red, green and blue LEDs. In case one of the duty cycles reaches the limit value, the reference signals for the red, green and blue light are decreased with the same relative amount. The color point of the light is thereby maintained, even when the efficiency of part of the LEDs decreases.