一种小点间距LED显示屏画面偏色的补偿方法

Compensation Method for Color Cast of Fine Pixel Pitch LED Display

针对小点间距LED显示屏常见的两种偏色问题,即白平衡偏色和首行偏暗,设计了一种可以同时解决两种问题的电路。由于红绿蓝三种LED的寄生参数不同,使得白平衡偏色。多行扫中第一行扫的列电压较其他列高时,导致第一行的LED导通电流偏低,使得第一行显示效果偏暗。该解决方案对两种情况下的PWM驱动信号进行补偿,并且提供了不同的补偿等级,补偿后,显示画面灰度精准、均匀性高,很好地解决了以上两种问题。

For two common problems,color cast and first dim line in fine pixel pitch LED display,a circuit which could solve the two problems at the same time is designed.The color cast occurs because the parasitic parameters of red,green,blue LEDs are quite different.It affects the display which eventually causes the color cast.The first dim line occurs when the column voltage is higher than the other lines,so the current through the first line's LEDs is smaller than the normal value.At last,the first line would be darker than the other lines.The solution presented tries to compensate the PWM driver signal and offer different compensation levels.After compensation,the display shows accurate gray level and uniformity,which means the two problems are well solved.