The brightness problem of outdoor full-color LED display directly threatens the personal safety of drivers and pedestrians, while an over-bright outdoor full-color LED display can make pedestrians’ eyes feel uncomfortable, irritate the driver’s eyes, and affect safe driving. How to solve this problem?

It can be directly analyzed from the brightness of the outdoor full-color LED display. The following solutions can solve the problem of excessively high brightness of the outdoor full-color LED display, and readjust the brightness and color of the outdoor full-color LED display.

First, adjust the brightness.

1. Change the current flowing through the LED. Generally, the continuous working current of the LED tube is about 20 mA. Except for the saturation of the red LED, the brightness of the remaining LEDs is basically proportional to the current flowing.

2. Pulse width modulation (PWM): Using the frequency change that the human eye can perceive, the gray scale control is realized through pulse width modulation, that is, the light pulse width (that is, the duty cycle) is changed periodically, as long as the light is repeatedly lit If the period is short enough (that is, the refresh rate is high enough), the human eyes will not feel that the light-emitting pixels are shaking. Pulse width modulation is widely used because it is more suitable for digital control. The commonly used method is to use a microcomputer to provide an LED display. Most of the existing LED screens use pulse width modulation technology to control their gray levels.

Second, color adjustment.

Outdoor full-color LED display products adjust the color of the entire screen according to the red, green, and blue brightness of the LED light. The company determines the reference color according to the brightness ratio of the three colors of red, green and blue of the selected product. Generally, the lower brightness ratio is used as the reference color. When the reference color has reached the highest brightness, it can be used for other (two-color) or Two types (full color) are adjusted. When the display is two-color, in most cases, the green is used as the reference to adjust the working current of the red diode. Usually it is to reduce the working current, and adjust the standard to balance the color yellow, which will reduce the brightness of the entire outdoor full-color LED display. Adjusting the color of outdoor full-color LED display to the best balance state will cause the brightness of the screen to decrease. If the outdoor full-color LED display screen achieves the maximum brightness of each color in order to meet the brightness requirements, the color balance will be lost. For example, the yellow color in the two-color screen is reddish or greenish.