(19)
(11)EP 2 197 241 A3

(12)EUROPEAN PATENT APPLICATION

(88)Date of publication A3:
30.11.2011 Bulletin 2011/48

(43)Date of publication A2:
16.06.2010 Bulletin 2010/24

(21)Application number: 09178306.8

(22)Date of filing:  08.12.2009
(51)International Patent Classification (IPC): 
H05B 33/08(2006.01)
F21S 8/00(2006.01)
(84)Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR
Designated Extension States:
AL BA RS

(30)Priority: 12.12.2008 US 334269

(71)Applicant: Palo Alto Research Center Incorporated
Palo Alto, California 94304 (US)

(72)Inventor:
  • Maeda, Patrick Y.
    Mountain View, CA 94040 (US)

(74)Representative: Gervasi, Gemma et al
Notarbartolo & Gervasi GmbH Bavariaring 21
80336 München
80336 München (DE)

  


(54)Control system for light-emitting device


(57) A control system for a light-emitting device may include test circuitry, photodetectors, and process circuitry. The test circuitry is configured to sequentially drive individual groups of light-emitting elements in a light-emitting device during a test sequence. Each group of light-emitting elements includes one or more light-emitting elements. The photodetectors are configured to detect an intensity of light present at a plurality of locations of the light-emitting device during the test sequence and generate a detection signal corresponding to the detected intensity of light. The process circuitry is configured to process the detection signals and transmit an adjustment signal based on the processing. The light-emitting elements may then be driven such that at least one characteristic of light emitted by all of the plurality of light-emitting elements is substantially the same at each of the plurality of locations of the light-mixing region.







Search report