TFT color screen working principle

Simply put, the basic principle of screen display is to fill the liquid crystal material between two parallel plates, and use voltage to change the arrangement of the molecules inside the liquid crystal material to achieve the purpose of shading and transmitting light to display different shades. , Scattered and consistent images, and as long as the three-color filter layer is added between the two plates, color images can be displayed.

Knowing its structure and principles, and understanding its technical and technological characteristics, can you have a targeted when purchasing, and be more scientific and reasonable in application and maintenance. Liquid crystal is an organic compound composed of long rod-shaped molecules. In the natural state, the long axes of these rod-shaped molecules are roughly parallel. The first feature of LCD is that the liquid crystal must be filled between two planes with fine grooves to work normally. 

The grooves on these two planes are perpendicular to each other (intersect at 90 degrees). That is to say, if the molecules on one plane are arranged in the north-south direction, the molecules on the other plane are arranged in the east-west direction, and the molecules between the two planes are arranged in the east-west direction. Forced into a state of 90-degree twist. Since the light travels along the direction of the arrangement of the molecules, the light is also twisted 90 degrees when passing through the liquid crystal. But when a voltage is applied to the liquid crystal, the molecules will be re-arranged vertically, so that the light can be directed out without any twisting. The second characteristic of LCD is that it relies on polarization filters and the light itself. Natural light diverges randomly in all directions. Polarization filters are actually a series of thinner and thinner parallel lines. 

These lines form a net to block all the light that is not parallel to these lines. The line of the polarization filter is exactly perpendicular to the first one, so it can completely block the light that has been polarized. Only when the lines of the two filters are completely parallel, or the light itself has been twisted to match the second polarized filter, the light can penetrate. LCD is composed of two polarized filters that are perpendicular to each other, so under normal circumstances, all light that attempts to penetrate should be blocked. However, because the two filters are filled with twisted liquid crystals, after the light passes through the first filter, it will be twisted 90 degrees by the liquid crystal molecules, and finally pass through the second filter. On the other hand, if a voltage is applied to the liquid crystal, the molecules will rearrange and be completely parallel, so that the light will no longer be twisted, so it will be blocked by the second filter. In short, power is applied to block the light, and no power is applied to cause the light to emerge. Of course, it is also possible to change the arrangement of the liquid crystals in the LCD so that light is emitted when power is applied, but is blocked when power is not applied. However, since the LCD screen is almost always on, only the solution of "power on and block light" can achieve the most power saving purpose.