关于点阵式LED动态背光源及其驱动电路的设计

由于液晶本身不发光，需要通过背光照明，因此目前大多数产品采用冷阴极射线荧光灯（CCFL）作为背光源，但因CCFL的亮度不容易控制和响应速度慢等缺点，造成液晶显示的能源浪费和动态模糊。文章提出了一种基于点阵式LED的动态背光源结构，将单个LED发出的光投射区域限制在散光膜的单一区域，即每个LED只负责液晶部分区域的背光照明。文章还设计了动态背光源的驱动电路，通过对显示的画面进行分析．采用亮度动态控制的方式可以得到不同区域的最佳亮度，同时驱动LED背光达到相应的亮度。并利用Matlab软件仿真LED背光源，结果表明采用动态背光源能有效地降低功耗．提高图像对比度。

The Matrix LED Dynamic Backlight and Drive Circuit's Design

Because of its non-luminous, the liquid crystal needs backlight. At present majority use the Cold Cathode Fluorescent Lamp(CCFL) as backlight. But the brightness is not easy to be controlled and response slow and so on disadvantages of CCFL, it results the energy wasted and motion blur of the liquid crystal display. This study introduced a structure of direct dynamic backlights based on LEDs, in which the light emission of every LED was restricted to a smaller area on the diffuser film and every LED was only responsible to illuminate one part of LCD. Designed the drive circuit of dynamic backlight, the LED backlight achieves the corresponding brightness by the analysis to the demonstration picture to obtain the parts of different best brightness and using the way of dynamic controlling the brightness. Using Matlab software simulation LED backlight, results show that the dynamic backlight can effectively reduce power consumption and improve image contrast.