The LED display quality can be mainly signed from the following aspects:
1.Flatness
The surface flatness of the display should be within ±1mm to ensure that the displayed image does not distort, and local raised or recessed leads to a blind angle of the viewing angle of the display. Between the box and the box, the gap between the module and the module should be within 1mm. Excessive gaps can result in noticeable display boundaries and visual inconsistencies. The flatness is mainly determined by the production process.

2. Brightness and viewing angle
Indoor full-color screen brightness to 800cd/m2 or more, outdoor full-color screen brightness to 5000cd/m2 or more to ensure the normal operation of the display, otherwise it will be too low brightness and can not see the displayed image. The brightness of the display is not as bright as possible and should match the brightness of the LED package. Blindly increasing the current and increasing the brightness will cause the LED to be cut off too quickly and the life of the display panel will drop rapidly. The manufacturer may be required to provide a parameter report to confirm. The size of the screen brightness is mainly determined by the quality of the LED die.

The viewing angle refers to the maximum angle you can see from the screen to the entire screen. The size of the viewing angle directly determines the number of display audiences, so the bigger the better. The viewing angle must be above 150 degrees. The size of the viewing angle is mainly determined by the packaging method of the die.

3. White balance effect
The white balance effect is one of the most important indicators of the display. In color science, when the ratio of the three primary colors of red, green, and blue is 1:4.6:0.16, pure white color will be displayed. If the actual proportion is slightly different, there will be a white balance deviation. Generally, it should be noted whether the white color is blueish or yellowish. Green phenomenon. In monochrome, the difference in brightness and wavelength between the LEDs is as small as possible. Standing on the side of the screen to see no color difference or color cast, the consistency is better. Whether the white balance is good or bad is mainly determined by the brightness and wavelength ratio of the LED die and the control system of the display. The die also affects the reducibility of the color.

4. Reducibility of color
The reproducibility of color refers to the reproducibility of the display screen to the color, and the color of the display screen must be highly consistent with the color of the playback source so as to ensure the realism of the image.

5. there is no mosaic, dead point phenomenon
Mosaic refers to the light or dark four squares appearing on the display screen, which are both the phenomenon of necrosis of the module. The main reason is that the quality of the IC or connector used in the display is not critical. The dead point refers to a single point that appears on the display screen, either constantly or normally. The number of dead spots is mainly determined by the quality of the die and the manufacturer’s anti-static measures.

6. There is no color block
Color blocks refer to the obvious color difference between neighboring modules. The color transition is based on the module. The color block phenomenon is mainly caused by poor control system, low gray level, and low scan frequency.

7. Display stability
Stability refers to the quality of the LED display screen after it is finished in the aging stage. It can be judged by the number of conditions that occur during the aging of the screen body by the manufacturer.

8. Security
The LED display is composed of multiple cabinets. Each cabinet must be protected by external grounding. The grounding resistance should be less than 0.1 Euro. And can withstand high pressure, 1500V1min does not breakdown. Marks and slogans must be warned at the high voltage input and at the high voltage connection of the power supply.

9. Package transportation
LED display screens are valuable goods and they are very heavy. The packing methods used by manufacturers are very important. It is generally packaged in a single box. Each side of the box must be protected by a buffer. The box has little room for internal activities during transportation. The outer box must have a clear logo.