RGB-based method for adjusting white balance of LED backlight

Abstract

An RGB (red, green and blue) based method for adjusting white balance of an LED backlight comprises the following steps: when a display runs independently, adjusting the backlight to a new brightness level after powering up; reading the value of a temperature sensor on a backlight board; reading the drive current duty ratio of the backlight corresponding to the brightness level and the standard value of a color sensor at the temperature; turning on the backlight according to the read drive current duty ratio; reading the values of red, green and blue in the color sensor on the backlight board and comparing the actual value and the standard value of the current color sensor; and if the actual value is more than the standard value of the current color sensor, reducing a bit of the current duty ratio of the backlight, conversely, increasing a bit of the current duty ratio of the backlight. In order to obtain the drive current duty ratio and the standard value of the color sensor, the method adopts particle swarm optimization. The method has the advantages of adjusting white balance automatically at wide temperature, accelerating the response speed, relieving the labor intensity and improving the efficiency.

Description

【Technical field】 [0001] The invention belongs to the technical field of LED backlights for liquid crystal displays, and in particular relates to a wide temperature range dynamic white balance adjustment method based on RGB three-color LED lamps. 【Background technique】 [0002] In the field of flat panel display, the traditional CRT (Cathode Ray Tube, cathode ray tube) has been gradually replaced by the increasingly advanced LCD (Liquid Crystal Display, liquid crystal display) due to its high radiation, high power consumption, large size, and heavy weight. The liquid crystal display itself cannot emit light, and a white light source with uniform brightness distribution needs to be added after the liquid crystal display to display images. Currently, the LCD backlight is mainly based on CCFL (Cold-Cathode Fluorescent Lamps, cold cathode ray tube). It has the characteristics of linear luminescence, high brightness and uniform light source. However, a high voltage of 1,000V or...

AI Technical Summary

Problems solved by technology

The backlight using all white light-emitting diodes has a large deviation from the standard white color, and it is difficult to completely reproduce the original color of the object; while the backlight using red, green and blue three-color light-emitting diodes has the problem of white balance adjustment

Due to the different attenuation characteristics of the three colors of LEDs with temperature and time, there will be inconsistent luminance after long-term use, resulting in poor white balance, especially at low temperature (-40°C) and high temperature (60°C) , the problem will be more serious

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