Part-I - Controller General of Patents Designs and Trademarks

(12) PATENT APPLICATION PUBLICATION (21) Application No.1527/CHENP/2012 A
(19) INDIA
(22) Date of filing of Application :20/02/2012 (43) Publication Date : 21/06/2013
(54) Title of the invention : METHOD AND APPARATUS FOR CONTROLLING DIMMING LEVELS OF LEDS
(51) International classification :H05B33/08
(31) Priority Document No :61/236998
(32) Priority Date :26/08/2009
(33) Name of priority country :U.S.A.
(86) International Application No
Filing Date
(87) International Publication No : NA
(61) Patent of Addition to Application
:NA
Number
:NA
Filing Date
(62) Divisional to Application Number
Filing Date
:PCT/IB2010/053729
:18/08/2010
:NA
:NA
(71)Name of Applicant :
1)KONINKLIJKE PHILIPS ELECTRONICS N.V.
Address of Applicant :GROENEWOUDSEWEG 1
EINDHOVEN 5621 BA NETHERLANDS
(72)Name of Inventor :
1)CLAUBERG Bernd
2)GREISCHAR Richard
3)SHROTRIYA Ameya
(57) Abstract :
Circuits useful in achieving efficient current control of LEDs based on a dimming control input are described. The circuits use a
combination of PWM dimming and analog dimming to achieve a highly efficient LED driver over a wide range of dimming from
near 0% to 100% light output.
No. of Pages : 24 No. of Claims : 14
The Patent Office Journal 21/06/2013 13832