(19)
(11) EP 2 955 711 A8

(12) CORRECTED EUROPEAN PATENT APPLICATION
Note: Bibliography reflects the latest situation

(15) Correction information:
Corrected version no 1 (W1 A1)

(48) Corrigendum issued on:
16.03.2016 Bulletin 2016/11

(88) Date of publication A3:
16.12.2015 Bulletin 2015/51

(43) Date of publication:
16.12.2015 Bulletin 2015/51

(21) Application number: 14172195.1

(22) Date of filing: 12.06.2014
(51) International Patent Classification (IPC): 
G09G 3/34(2006.01)
G09G 5/02(2006.01)
 F21K 99/00(2016.01)
(84) Designated Contracting States:
AL 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 RS SE SI SK SM TR
Designated Extension States:
BA ME

(30) Priority: 09.05.2014 US 201461991321 P

(71) Applicant: ams AG
8141 Unterpremstätten (AT)

(72) Inventors:
  • Ghoshal, Sajol Christopher
    78759 Austin, Texas (US)
  • Afshari, Sina
    12180 New York, New York (US)

(74) Representative: Epping - Hermann - Fischer 
Patentanwaltsgesellschaft mbH Schloßschmidstraße 5
80639 München
80639 München (DE)

   


(54) Method for calibrating a color space transformation, method for color space transformation and color control system


(57) A method of calibrating a color space transformation accordingly comprises the driving of a light source at a first ambient temperature (T1). The light source is tuned to emit light with a number N of combinations of at least two correlated color temperatures and at least two intensities. Furthermore, for each of the N combinations, color coordinates are received by a processing unit including first red coordinates, first green coordinates and first blue coordinates derived from measurements in the RGB color space, and first x-coordinates, first y-coordinates and first z-coordinates derived from measurements in the XYZ color space. Respective 3xN matrices RGB_1 and XYZ_1 are subsequently constructed based on the received coordinates, and a 3x3 conversion matrix C is generated to fulfil the relation XYZ_1 = C*RGB_1.