Posted on: March 28, 2024 Posted by: eleanorwalter57 Comments: 0

First of all, LED devices are the most critical components of full-color LED displays for three reasons:

First of all, LED is the key component used in the largest number of full-color screens, and thousands to tens of thousands of LEDs are used per square meter;

Secondly, LED is the main body that determines the optical display performance of the entire screen, which directly affects the audience’s evaluation of the display screen;

Again, LEDs account for the largest proportion of the overall cost of the display, ranging from 30% to 70%. The choice of LED determines the quality of more than 50% of the entire display. If you fail to choose a good LED, no matter how good the other parts of the display are, it will not be able to make up for the defects in the quality of the display.

The important indicators reflecting the quality of LEDs dedicated to full-color LED displays mainly include:

1. Failure rate

Since the full-color display screen consists of tens of thousands or even hundreds of thousands of groups of red, green, and blue LEDs, the failure of any color LED will affect the overall visual effect of the display screen. Generally speaking, according to industry experience, the failure rate of the LED display screen should not be higher than 3/10,000 (referring to the failure caused by the LED device itself) from the beginning of assembly to the aging of 72 hours before shipment.

2. Antistatic ability

LED is a semiconductor device, which is sensitive to static electricity and can easily cause electrostatic failure. Therefore, antistatic ability is very important for the life of the display screen. Generally speaking, the failure voltage of LED human body electrostatic mode test should not be lower than 2000V.

3. Attenuation characteristics

Red, green, and blue LEDs all have the characteristic of brightness decay as the working time increases. The quality of LED chips, the quality of auxiliary materials and the level of packaging technology determine the attenuation speed of LEDs. Generally speaking, after 1000 hours, 20 mA room temperature lighting test, the attenuation of red LED should be less than 10%, and the attenuation of blue and green LED should be less than 15%. The consistency of red, green and blue attenuation is very important for full-color LED display The white balance of the screen will have a great influence in the future, which in turn will affect the display fidelity of the screen.

4. Brightness

LED brightness is an important determinant of display brightness. The higher the brightness of the led video screen panels, the larger the margin of the current used, which is good for saving power consumption and maintaining the stability of the LED. LEDs have different angle values. When the brightness of the chip is fixed, the smaller the angle, the brighter the LED, but the smaller the viewing angle of the display. Generally, a 100-degree LED should be selected to ensure a sufficient viewing angle for the display. For displays with different dot pitches and different viewing distances, a balance point should be found in brightness, angle and price.

5. Consistency

The full-color display screen is composed of countless red, green, and blue LEDs. The brightness and wavelength consistency of each color LED determine the brightness consistency, white balance consistency, and chromaticity of the entire display screen. consistency. Generally speaking, display manufacturers require device suppliers to provide LEDs with a wavelength range of 5nm and a brightness range of 1:1.3. These indicators can be achieved by device suppliers through grading by spectroscopic and color separation machines. Voltage consistency is generally not required.

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