What factors will cause the LCD screen to flash
Date:2019-03-04
With the development of science and technology, LCD applications can be seen everywhere, such as vehicle products, industrial instruments and other electronic devices. When the LCD screen in the use of the process will always appear flashing, which affects people's use, in the end what factors lead to the LCD screen flashing? Hangzhou Xuhong listed and analyzed the possible factors as follows:
1、 Incorrect setting of refresh frequency causes LCD screen to flash
LCD screen for this kind of flash screen, the phenomenon is that the screen display is not stable when playing animation or switching pictures quickly, one or two horizontal stripes may appear and the position is not fixed. This is related to two frequencies, one is the frequency of sending data from CPU to ram, the other is the internal refresh frequency of the module. The refresh rate can be matched with the CPU write speed by adjusting the register. In addition, customers can also make the two match by changing the CPU's write speed.
2、 The inconsistent scanning direction causes the LCD screen to flash
The phenomenon of LCD flashing is very similar to the phenomenon of frequency mismatch mentioned above. This phenomenon does not occur very often. However, due to the limited contact, it may not be considered in this direction sometimes when there is a problem. No matter how to adjust the frequency, the phenomenon still exists all the time, At this time, we need to check whether the update direction of CPU sending data to ram is consistent with the refresh direction of module.
3、 The mismatch between IC refresh frequency and backlight PWM signal frequency causes the LCD screen to flash
This situation often occurs in the CSTN module, and it is easy to occur in the half bright state. The reason is that the PWM signal deceives people's eyes by constantly switching the backlight between the bright state and the dark state. It gives people the feeling that the backlight is dark, and the condition is that the frequency should be fast enough. If this frequency does not match the refresh frequency of the IC, The two frequencies may interfere with each other and make the picture appear similar to water ripple. This phenomenon often occurs in the silicon IC. In order to make the power smaller, their IC usually sets the default crystal frequency lower, so this phenomenon often occurs in the semi bright state. Improvement measures: change the crystal oscillator frequency and refresh frequency to see the effect. Since the cycle becomes smaller after changing the crystal oscillator to be larger, the possibility of matching will be greater, so the general debugging direction is to increase the refresh frequency of IC. In addition, customers can adjust the PWM signal appropriately to cooperate with debugging.
Hangzhou Xuhong Technology Co., Ltd. is a technology-based company of industrial color LCD module, industrial control display products and touch screen control. It is a professional supplier of industrial LCD drive solutions. It is an enterprise unit that carries out display and touch control of terminal equipment through LCD products and display drive solutions. Our long-term stable supply of 3.5 "- 32" industrial LCD screen, TFT LCD screen brand diversification, complete models, can meet different customers under different application environments, medical, vehicle special industry wide temperature, bright, wide angle Industrial LCD screen all stable supply.
