Integrated backlight dimming method and device for enhancing liquid crystal display contrast ratio

Abstract

The invention discloses an integrated dimming method for a liquid crystal display backlight source, and the integrated dimming method comprises the following steps: carrying out the statistics analysis on input images, thus obtaining a backlight dimming factor k (0<=k<=1); integrally changing the backlight brightness according to the k and simultaneously generating an S curve according to the characteristic values of the images; and independently compensating each liquid crystal pixel according to the S curve, wherein the pixel compensation factor with the brightness larger than the inflection point of the S curve is larger than 1 and the pixel compensation factor with the brightness less than the inflection point of the S curve is less than 1, thereby effectively enhancing the display contrast ratio and simultaneously reducing the energy consumption. The invention also discloses a backlight device with a global dimming function, and the backlight device comprises an LED (Light Emitting Diode) light source plate, a video signal interface plate, an LED driving plate, an FPGA (Field Programmable Gate Array) control plate and the like. The dimming algorithm disclosed by the invention can be used for enhancing the dynamic contrast ratio and also effectively enhancing the static contrast ratio and can be used for direct descending type backlight and side emitting type backlight.

Description

technical field [0001] The invention relates to the technical field of liquid crystal display, in particular to a backlight overall dimming method and device for improving the contrast of liquid crystal display. Background technique [0002] After 30 years of development, Liquid Crystal Display (LCD) has become the mainstream technology of flat panel display. Liquid crystal molecules do not emit light by themselves, and need a backlight to illuminate the display area. Currently used LCD backlight sources mainly include cold cathode fluorescent lamps (Cold Cathode Fluorescent, CCFL) and light emitting diodes (Light Emitting Diode, LED). LED has the advantages of long life, green environmental protection, fast response time, etc., and its application in the field of liquid crystal display is gradually expanding. [0003] Liquid crystal display has two inherent disadvantages: (1) low contrast; (2) high power consumption. At present, many researchers use backlight dynamic dim...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to provide a global dimming method for LED backlights of liquid crystal displays. This method not only solves the problem that the existing dimming algorithm cannot improve the static contrast, but also has fewer control channels, low hardware cost, no Light crosstalk and other advantages, suitable for direct-type backlight and side-type LED backlight

[0009] Another object of the present invention is to provide a backlight device that helps to improve the static contrast and dynamic contrast of liquid crystal display, so as to solve the problems of low contrast and high energy consumption of liquid crystal display

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