Full-color LED display pixels out of control what to do

Time:2018-10-13 Views:1515

The loss of pixels in full-color LED display is a common problem. What is the cause of this phenomenon and how to solve it?Let‘s take a look at it.

LED display pixels out of control refers to the display‘s smallest imaging unit (pixel) does not work properly.The ratio of out of control pixels to the total number of full-screen pixels is called "out of control rate of full-screen pixels".There are two types of pixel mode out of control. One is blind spot, which is blind spot.The second is the constant light, when the need is not bright it has been light, called constant light.

Generally, the pixels of common LED display screen are composed of 2R1G1B(2 red lights, 1 green light and 1 blue light, as follows) and 1R1G1B. Losing control generally does not mean that red, green and blue lights in the same pixel are all out of control at the same time.Therefore, it can be concluded that the main reason for the loss of pixels in full-color LED display is that LED lights are out of control.The main reason of LED lamp failure can be divided into two aspects.The second is the improper use of methods.

LED lights out of control cannot be found in routine testing of leds.Under severe conditions such as high temperature, low temperature and rapid change of temperature, the thermal expansion coefficient of LED chips, epoxy resin, supports, internal leads, cementitious glue, PPA cup body and other materials is different, which leads to different internal stresses.The mechanism of LED losing control due to electrostatic discharge is very complicated. Equipment, tools, utensils and human body may carry static electricity and discharge it. This kind of static electricity is less than hundreds of volts, higher than tens of thousands of volts, and the discharge time is at the nanosecond level.If blue and green tube is out of control, LED-PN junction is usually broken through by electrostatic discharge.Because of the complex production process of LED display screen, electrostatic discharge is difficult to prevent, so electrostatic protection must be throughout the whole production process.

Under different circumstances, the actual requirements of pixel loss rate are different, and the full-color LED display indicators are required to be controlled within 1%.The single color LED display indicator shall be controlled within one tenth.At present, there is no good solution for full-color LED display pixels. It is suggested to contact the service manufacturer to return to the factory for repair. If the maintenance cost is too high, we can consider replacing the module unit board with the problem.

At present domestic LED display will be aging test, before they go out to runaway pixel leds will repair replacement, "whole screen pixels of rate control, within 1/104" area rate of pixels is out of control "are controlled within 3/104 is no problem, even with individual manufacturer enterprise standards are not allowed to appear before the factory is out of control pixels, but this is bound to increase the manufacturer‘s maintenance cost and to extend the time of shipment.

In different applications, the actual requirements of pixel loss rate can be quite different. Generally speaking, LED display is used for video playback, and it is acceptable and achievable to control the indicator within 1/104.For simple character information publishing, it is reasonable to require metrics to be within 12/104.