Reasonable brightness adjustment of LED full-color large screen

"Brightness Differences of LED Full-color Large Screens" Large-scale LED screens are widely used outdoors. The large screens enrich people's night life, promote urban culture, and let the cultural atmosphere overflow the streets and alleys. If the brightness is too high, it will have a certain impact on people's daily life. 1. How to identify the brightness of the large LED screen? 1. Make a 3V DC power supply that is easy to connect to the LED by yourself, preferably with a battery. You can use two button batteries, put them in a small plastic tube and lead out two probes as the positive and negative output, and use shrapnel at the end to directly make a switch. When in use, the positive and negative probes correspond to the positive and negative electrodes of the LED. Negative pin, press and hold the switch at the end, the light-emitting tube will be electroluminescent. 2. Secondly, use a photoresistor and a digital multimeter to form a simple light metering device, lead out two thin wires from the photoresistor, and connect them directly to the two test leads of the digital multimeter, and place the multimeter at the 20K position (depending on the photoresistor, Try to make the reading as accurate as possible), note that the measured value is actually the resistance value of the photoresistor, so the brighter the light, the smaller the value. 3. Take an LED light-emitting diode and light it with the above 3V direct current. The light-emitting head is facing and clinging to the photosensitive surface of the connected photoresistor. At this time, the multimeter will display a reading to distinguish the luminous brightness of the LED. 2. The brightness discrimination level refers to the brightness level of the image that can be distinguished by the human eye from the darkest to the whitest. Some of the gray levels of LED full-color screens are very high, which can reach 256 or even 1024 levels. However, due to the limited sensitivity of the human eye to brightness, these gray levels cannot be fully recognized. That is to say, many adjacent levels of grayscale may look the same to human eyes. And the ability of eyes to distinguish varies from person to person. For large screens, the more levels of human eye recognition, the better, because the displayed images are for people to see after all. The more brightness levels the human eye can distinguish, the larger the color space of the large screen and the greater the potential for displaying rich colors. The brightness identification level can be tested with special software. Generally, if the large screen can reach level 20 or above, it is considered a relatively good level. 3. Requirements for brightness and viewing angle: The brightness of the indoor full-color LED large screen must be above 800cd/m2, and the brightness of the outdoor LED full-color screen must be above 1500cd/m2 to ensure the normal operation of the large screen. The displayed image is too low to be seen clearly. The brightness is mainly determined by the quality of the LED tube core. The size of the viewing angle directly determines the audience size of the large LED screen, so the bigger the better. The viewing angle is mainly determined by the die package. It is very necessary to determine the brightness of LED large screens. The current brightness requirements for LED large screens for urban lighting may be newly stipulated. If the brightness of LED screens is too high, it will cause trouble to nearby residents. In order to avoid bad repercussions, this requires merchants to have relevant professional knowledge when customizing and maintaining LED large screens. The control of brightness has always been a matter of great concern to everyone. Although high brightness is one of the important advantages of LED large screens, in a certain sense, the technology of freely controlling brightness has not been achieved. With the clear introduction of full-color grayscale technology in 2012, LED full-color screen technology has taken a big step forward. .