Patent · US Expired

Liquid crystal display having an improved lighting device

US6636190B2 · kind B2 · utility

166Cited by
6References
27Claims
0Family size

Assignees

Inventors

Key dates

Filing dateAug 23, 2001
Grant dateOct 21, 2003
Priority date
Expiry dateMar 5, 2022

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG09G2330/045
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A liquid crystal display device includes a liquid crystal display panel and a lighting device. The lighting device is supplied with alternately a first current during a period t1 and a second current during a second period t2 such that electric power E1 is lower than electric power E2. E1 is defined as (t1×ip-p(1)×Vp-p(1))/2+(t2×ip-p(2)×Vp-p(2))/2, where ip-p(1)=a peak-to-peak value of the first current, Vp-p(1)=a peak-to-peak value of a voltage across the light source during the period t1, ip-p(2)=a peak-to-peak value of the second current, and Vp-p(2)=a peak-to-peak value of a voltage across the light source during the period t2. E2 is defined as (t1+t2)×Ieff×Veff, where Ieff and Veff are effective values of the current and voltage of the light source, respectively.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.