Out-of-control pixels on full-color LED displays is a relatively common problem. What is the cause of this phenomenon and how to solve it? Today I will analyze it with you.

Analysis of the causes of out-of-control pixels in full-color LED displays

The pixels of the LED display screen are out of control, which means that the smallest imaging unit (pixel) of the display screen is not working properly. The ratio of the number of out-of-control pixels to the total number of pixels in the entire screen is called the "out-of-control pixel rate of the entire screen." There are two types of pixel out-of-control modes. One is a blind spot, which is a blind spot. It does not light up when it needs to be bright, which is called a blind spot. The other is a constant bright spot, which keeps lighting up when it needs to not light up. This is called a blind spot. It's always a highlight.

Generally, the common LED display pixel compositions are 2R1G1B (2 red lights, 1 green light and 1 blue light, the same as below) and 1R1G1B, and the out-of-control pixels are generally not red, green, and pixels in the same pixel. All blue lights are out of control at the same time, but as long as one of the lights is out of control, we consider this pixel to be out of control. Therefore, it can be concluded that the main reason for the out-of-control pixels of the full-color LED display is the out-of-control LED lights. The main reasons for the failure of LED lights can be divided into two aspects: one is the poor quality of the LED itself; the other is improper use.

Out-of-control LED lights cannot be found during routine inspection and testing of LEDs. Under harsh conditions such as high temperature, low temperature, and rapid temperature changes, the differences in thermal expansion coefficients of materials such as LED chips, epoxy resins, brackets, inner leads, die-bonding adhesives, and PPA cups lead to differences in internal stress. The mechanism by which electrostatic discharge causes LEDs to run out of control is very complex. Equipment, tools, utensils, and the human body may contain static electricity and discharge it. This static electricity can range from a few hundred volts to tens of thousands of volts, and the discharge time is at the nanosecond level. . If the blue and green tubes are out of control, it is often caused by the breakdown of the LED-PN junction by electrostatic discharge. Due to the complicated production process of LED display screens, it is difficult to prevent electrostatic discharge. Therefore, electrostatic protection must be throughout the entire production process.

In different situations, the actual requirements for the pixel out-of-control rate are different. The indicators of full-color LED displays are required to be controlled within one percent; the indicators of monochrome LED displays are required to be controlled within one-tenth. At present, there is no good solution for the pixels of the full-color LED display. It is recommended to contact the service manufacturer to return it to the factory for repair. If the repair cost is too high, you can consider replacing the faulty module unit board.

At present, domestic LED displays will undergo aging tests before leaving the factory, and LED lights with out-of-control pixels will be repaired and replaced. The "out-of-control pixel rate of the whole screen" is controlled within 1/104, and the "out-of-control pixel rate of regional pixels" is controlled within 3/ There is no problem within 104, and some manufacturers even have corporate standards that require that out-of-control pixels are not allowed before leaving the factory. However, this will inevitably increase the manufacturer's manufacturing and maintenance costs and extend the shipping time.

Even if there is no out-of-control point before leaving the factory, special attention should be paid during the installation process of the display screen to prevent the lights from hitting, otherwise it will increase unnecessary costs for the installation and construction. It is also recommended to find appropriate technical on-site technical support during installation to ensure that the out-of-control point is within Control within appropriate requirements before acceptance.