How to solve the different brightness of LED display colors

A good led full-color display must adapt to different temperatures, different weather, and can be used normally in various occasions. It also needs to have a good effect on the distant and near light. Especially in large-scale concerts, the special effect lighting should be particularly excellent. But sometimes we will find that the brightness of the LED is different. What is the reason for the inconsistent brightness of the LED full-color display? Sostron concluded that the following three factors can cause the brightness inconsistency of LED full-color display.

1. Light emitting element

Led full-color display light-emitting components, that is, LED light-emitting tubes, are inevitably inconsistent in brightness in the production process. However, the countermeasure adopted by the manufacturers of LED electronic display screen is to grade after production. The smaller the brightness difference between the two adjacent grades, the better the consistency. However, the more serious the appearance of low yield and high inventory will be. Therefore, each manufacturer controls the brightness difference between the two adjacent gears at 20%.

2. Drive element

The driver of LED full-color display screen is usually a constant current driver chip, such as mbl5026. These chips include 16 constant current drive outputs, and the current output value can be set with resistance. The error of each output of the same chip is controlled within 3%, and that of different chips is controlled within 6%. It is normal for 25% brightness error to appear between pixels of LED full-color display screen. If the LED light-emitting tube used is not the same level and type of full-color LED display screen, the brightness error will rise to more than 40%.

In addition, it is worth noting that the inconsistent brightness of the full-color LED display screen is the fundamental reason for the formation of the flower screen, which cannot be corrected by the later proofreading equipment, as long as it is realized by the manufacturing process of the LED display screen manufacturer. So if you buy a screen with inconsistent brightness, please contact your service provider or manufacturer to solve the problem.

3. The display screen is mixed with materials in the production process, and different batches of dot matrix are used.

LED electronic displays

How to solve the color difference of LED electronic display screen?

The first method is to change the current flowing through the LED. Generally, the LED tube allows a continuous working current of about 20 mA. Except that the red LED is saturated, the brightness of other LEDs is basically proportional to the current flowing;

The second method: using the visual inertia of the human eye, the pulse width modulation method is used to realize the gray level control, that is, the light pulse width (i.e. duty cycle) is changed periodically. As long as the cycle of repeated lighting is short enough (i.e. the refresh frequency is high enough), the human eye can not feel the light-emitting pixels shaking. Since pulse width modulation is more suitable for digital control, almost all LED electronic displays use pulse width modulation to control the gray level today, when computers are widely used to provide and display the content of LED displays.