Patent · US Active

Liquid crystal display and scanning back light driving method thereof

US8803925B2 · kind B2 · utility

1Cited by
4References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 23, 2011
Grant dateAug 12, 2014
Priority date
Expiry dateDec 26, 2031

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG09G2320/064
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A liquid crystal display includes a scanning backlight controller, that calculates a turn-on duty ratio of a pulse width modulation (PWM) signal for controlling turn-on and turn-off operations of light sources, and a light source driver, that synchronizes a frequency of the PWM signal with a frame frequency or synchronizes the frequency of the PWM signal with the frame frequency, changes the calculated turn-on duty ratio of the PWM signal to a maximum value, and adjusts an amplitude of the PWM signal based on a changed degree of the turn-on duty ratio of the PWM signal, based on the result of a comparison between the turn-on duty ratio of the PWM signal and a previously determined critical value, and then sequentially drive the light sources along a data scanning direction of the liquid crystal display panel.

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