Global Patent Index - EP 1646033 A1

EP 1646033 A1 20060412 - Method for maintaining the white colour point over time in a field-sequential colour LCD

Title (en)

Method for maintaining the white colour point over time in a field-sequential colour LCD

Title (de)

Verfahren zum Erhaltung des Weisspunktes über die Betriebsdauer in einer Anzeigevorrichtung mit zeitsequentiellen Farbwiedergabeverfahren

Title (fr)

Procédé pour maintenir le point blanc pendant le temps d'utilisation dans un dispositif d'affichage à cristaux liquides à séquence de trames couleur

Publication

EP 1646033 A1 20060412 (EN)

Application

EP 04104887 A 20041005

Priority

EP 04104887 A 20041005

Abstract (en)

A field sequential liquid crystal display maintains its white colour point through compensation values to at least one colour light emitting diode that illuminates the display. The compensation values may be impedances to control the current or pulsing of the current source according to a pulse width modulation technique. A degradation curve may be used to calculate extrapolate the theoretical forward voltage of the light emitting diode. Additional complexity arises from the need for calculating uptime for multiple light emitting diodes of different colours. Brightness levels may also be factored in.

IPC 8 full level

G09G 3/34 (2006.01)

CPC (source: EP)

G09G 3/3413 (2013.01); G09G 2310/0235 (2013.01); G09G 2320/043 (2013.01); G09G 2320/064 (2013.01); G09G 2320/0666 (2013.01)

Citation (applicant)

Citation (search report)

Citation (examination)

Designated contracting state (EPC)

AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR

DOCDB simple family (publication)

EP 1646033 A1 20060412; CA 2519967 A1 20060405; CA 2519967 C 20121127

DOCDB simple family (application)

EP 04104887 A 20041005; CA 2519967 A 20050916