LED full-color screen color failure is difficult to prevent? Because you ignore this problem

What is the reason for the inconsistent brightness of outdoor LED full-color displays? According to the years of experience of LED electronic display manufacturers, the following three factors can lead to inconsistencies in the brightness of LED full-color displays.

1, light emitting elements

The LED full-color display light-emitting element is the LED light-emitting tube, and the brightness is inconsistent during the production process. However, LED electronic display manufacturers adopt the countermeasures to divide the files after the production is finished. The smaller the difference in brightness between the two adjacent files, the better the consistency, but the more severe the low yield and high inventory will be. Therefore, each manufacturer has controlled the brightness difference between two adjacent files at about 20%.

2, drive components

LED full color display driver components are usually constant current driver chips, such as MBl5026. These chips include 16 constant-current drive outputs. Resistors can be used to set the current output value. The error of each output of the same chip is controlled within 3%, and the output error of different chips is controlled within 6%. It is normal for 25% brightness error to appear between each pixel of LED full-color display. If the LED light tube used is not the same level and type of full-color LED display screen, it will cause the brightness error to rise above 40%.

It is also worth noting that the full-color LED display brightness is inconsistent, is the fundamental reason for the formation of Huaping, can not be corrected with the late proofreading equipment, as long as the LED display manufacturers produce manufacturing process to achieve. Therefore, purchase the screen with inconsistent brightness, please contact your service provider or manufacturer to solve the problem.

3, the display screen in the production process mixed with different batches of dot matrix.

How to solve the LED electronic display of different colors?

The first method is to change the current flowing through the LED. Generally, the LED tube allows the continuous operating current to be about 20 mA. In addition to the saturated phenomenon of the red LED, the brightness of other LEDs is basically proportional to the current flowing through.

The second method is to use the visual inertia of the human eye to implement the gray control by pulse width modulation method, that is, to periodically change the light pulse width (ie, duty cycle) as long as the period of this repeated lighting is short enough (ie, refresh The frequency is high enough that the human eye feels no jitter in the glowing pixels. Because pulse width modulation is more suitable for digital control, today, microcomputers are generally used to provide LED display content. Almost all LED electronic display screens use pulse width modulation to control the gray level.