When the TFT LCD display is disturbed, we will see water ripples, vertical grains, wood grains, multi-line ripples and other phenomena on the splicing screen. The following china custom lcd supplier Proculus will analyze the common factors that cause the interference of TFT uart display splicing.
There is an interference signal superimposed on the normal power supply, and the interference signal on this power supply mostly comes from the equipment using thyristor in the power grid. It is relatively simple to solve this problem, as long as the entire system of the LCD splicing screen is powered by a purified power supply or an online UPS, it can be solved.
Most of the interference phenomena on TFT lcd module products are caused by strong and high-frequency space radiation sources near the transmission system, the front end of the system or the central control room. To solve this problem, it is supposed to understand the surrounding environment when the system is established, and try to avoid or stay away from the radiation source.
This situation can be judged by investigation and understanding. If the cause is the source of interference, the solution is to strengthen the shielding of the camera and ground the pipeline of the video cable.
The manifestation of this phenomenon is that several vertical bars with equal spacing are generated on the monitor screen, and the frequency of the interference signal is basically an integer multiple of the line frequency. The solution generally relies on "starting series resistance" or "terminal parallel resistance".
In particular, the shielding performance is poor (the shielding net is not a very good quality copper wire net, or the shielding net is too thin to have a shielding effect). At the same time, the line resistance of this type of video line is too large, which causes a large attenuation of the TFT liquid crystal display signal, which is also the reason for aggravating the failure. In addition, the characteristic impedance of this type of video cable is not 75Ω and the parameters are out of specification is also one of the reasons for the failure.