Friday, June 10, 2022 at 1:46:34 AM GMT+00:00
1. White balance effect
4. Brightness and visual angle
5. Whether there is color block
6. Maximum brightness
7. Square power consumption
10. Packaging and transportation
The application of LED large screen will be more and more extensive with the progress and development of society. However, the quality of LED displays is uneven, and low-quality LED displays cause frequent accidents.
How do we judge the quality of LED displays?
LED white balance effect is one of the important indicators to measure the quality of display screen. In terms of RGB color, pure white will be displayed only when the ratio of red, green and blue primary colors is 1:4.6:0.16. If there is a deviation in the ratio of color brightness, there will be a deviation in the white balance. Pay attention to whether white is blue or yellow green. The quality of white balance is mainly determined by the quality of the lamp wick of the display screen itself, which determines the color reversibility of the display screen and directly affects the visual effect and use experience of the display screen.
It is felt that the picture is white and gray, and the picture transparency is not strong, indicating that the contrast of LED display screen is low, and its contrast value cannot be lower than 1000:1, which is mainly related to the packaging of LED lamp and the design of module mask. The contrast of LED lamp in black bracket is significantly higher than that of LED lamp in white bracket.
Uniformity refers to whether the display screen is clean and free of pits and mosaics, which is mainly related to the consistency of LED lamp brightness and color. The uniformity of brightness and color can be viewed by testing the screen in RGB monochrome and white state.
In general, the brightness of the indoor full color screen in the industry should be above 800cd/m2, and the brightness of the outdoor full color screen should be above 1500 cd/m2, so as to ensure that the display meets the brightness needs of each scene, otherwise the displayed image will not be clear because of the low brightness. The brightness is mainly determined by the quality of LED tube core. The size of the viewing angle directly determines the audience of the display screen, so the larger the better. The visual angle is mainly determined by the packaging method of the tube core.
The color block of LED display refers to the obvious color difference between the module display and the normal area. The color transition is based on the module. The color block phenomenon is mainly caused by the poor quality of the display circuit board, the poor quality of the IC chip, and the unqualified welding process.
Maximum brightness refers to the brightness of each primary color of LED display screen at the highest gray level and brightness under certain ambient illumination. In short, use the software to set the brightness measured in the normal direction with the light gun when the display screen is white 255.
For outdoor LED displays, there are different requirements for maximum brightness according to the use environment, because in situations where the ambient light is strong, the brightness of LED displays is required to be higher so that people can see clearly what is displayed on the screen. In general, the display screen facing north and south has lower requirements for maximum brightness, which can be met as long as it reaches 4000CD/m2, while the display screen facing south and south requires the full screen brightness to reach 7000CD/m2. The requirements for facing east and west are the same as those for facing south, because sunlight will directly shine on the LED display screen for a part of the time. Theoretically, it is enough that the brightness should be greater than 5500 CD square meters.
The square power consumption refers to the power consumption generated by the LED display screen with an area of one square meter. The unit is watt. The unit of electricity we usually say is watt/hour. For example, if the power consumption of one square meter LED display is 300 watts, the display will consume 300 watts per hour per square meter, that is, 0.3 kilowatt hour. The power consumption of LED display screen generally has two indicators, one is the maximum power consumption, and the other is the use power consumption. The maximum power consumption refers to the power consumption when the LED display screen is at its maximum brightness. How can you distinguish the maximum power consumption with your eyes? The method is simple: look at the number of power supplies behind the box and multiply it by the maximum power of each power supply.
The maximum power consumption per square meter can be calculated according to the size of the box. There are two types of power supplies, 200W and 300W. The use power consumption refers to the power consumption when playing advertising videos, texts and pictures. Since the use power consumption is directly related to the content played, it is difficult to have an exact value, but according to our experience, it is generally 1/3 of the maximum power consumption. Lower power consumption represents lower use cost and less heat. The amount of heat depends on the current, which directly affects the service life and stability of the display.
Stability refers to the reliable quality of LED display screen in the aging stage after it is made into a finished product. It can be determined by asking the manufacturer for aging records to get the number of conditions that occur during the aging of the screen.
The LED display screen is composed of several boxes. Each LED box must be provided with external passenger grounding protection, and the grounding resistance should be less than 0. 1 ohm. It can withstand high voltage without breakdown at 1500V for 1min. Warning signs and slogans shall be provided at the high-voltage input terminal and the high-voltage wiring of the power supply.
LED display screen belongs to valuable goods and is very heavy. The packaging method used by the manufacturer is very important. Generally, the box is packed as a single box, and each side of the box must have a protective object to buffer. The box has little internal activity space during transportation. The outer packing box must be clearly marked.
Through the above 10 aspects, we can identify the quality of LED display screen. When we look at a display screen again, we will know from which aspects to identify its quality level, so as to achieve the purpose of selecting a cost-effective product suitable for us. Because if you choose the right led display screen, you can easily get customers!