A good LED full-color display must be adapted to different temperatures, different weathers, and can be used normally in various occasions. It also has a good effect on the brightness of far and near, especially for large-scale concerts. The lighting needs to be particularly good, but sometimes we find that the brightness of the LED is not the same. What is the reason for the inconsistent brightness of the LED full-color display? Based on years of experience, the editor has summarized the following three factors that can cause the LED The brightness of the full-color display is inconsistent.
Full color led display
01Light-emitting element
LED full-color display light-emitting elements, namely LED light-emitting tubes, inconsistent brightness in the production process is inevitable. However, the countermeasure adopted by LED electronic display manufacturers is to perform classification after production is completed. The smaller the brightness difference between two adjacent files, the better the consistency, but the appearance of low yield and high inventory will be more severe. Therefore, each manufacturer controls the brightness difference between two adjacent gears at 20 percent .
02 drive components
LED full-color display drive components are usually constant current drive chips, such as MBl5026 and so on. These chips include 16 constant current drive outputs, which can be used to set the current output value. The error of each output of the same chip is controlled within 3 percent , and the output error of different chips is controlled within 6 percent . It is normal for a full-color LED display to show a brightness error of 25 percent between pixels. If the LED tube used is not the same level and type of full-color LED display, the brightness error will rise to more than 40 percent .
Full color led display
It is also worth noting that the inconsistency of the brightness of the full-color LED display is the fundamental reason for the formation of the screen. It cannot be corrected with the post-correction equipment, as long as it is realized by the LED display manufacturer during the production and manufacturing process. Therefore, if you buy a screen with inconsistent brightness, please contact your service provider or manufacturer to solve the problem.
The display is mixed with materials during the production process, and different batches of dot matrix are used. How to solve the color difference of LED electronic display?
Method 1
change the current flowing through the LED, the general LED tube allows a continuous working current of about 20 mA, except for the saturation of the red LED, the brightness of the 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 achieve gray scale control, that is, the light pulse width (ie duty cycle) is periodically changed, as long as the period of repeated lighting is short enough (ie the refresh frequency is high enough), The human eye does not feel that the luminous pixels are shaking. Because pulse width modulation is more suitable for digital control, today when microcomputers are generally used to provide and LED display content, almost all LED electronic displays use pulse width modulation to control gray levels.
