Simply put, the basic principle of screen display is to fill liquid crystal material between two parallel plates, through the voltage to change the arrangement of liquid crystal material internal molecules, in order to achieve the purpose of shading and light transmission to display different shades, well-spaced image, and as long as the two plates plus three color filter layer, you can achieve color image display.

intelligent TFT LCD module

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Understand its structure and principle, understand its technology and process characteristics, in order to have a target in the purchase, in the application and maintenance of more scientific and reasonable. Liquid crystals are organic compounds made of long rod-like molecules. In nature, the long axes of these rod-like molecules are roughly parallel.

The first characteristic of LCDS is that the liquid crystals must be inserted between two planes with thin grooves to work properly. The slots in the two planes are perpendicular to each other (90 degrees of intersection), meaning that if the molecules in one plane are aligned north-south, the molecules in the other plane are aligned east-west, and the molecules in between are forced into a 90-degree twist. Because light travels in the direction of the molecules, it is also twisted 90 degrees as it passes through the liquid crystal. But when a voltage is applied to the liquid crystal, the molecules rearrange themselves vertically, allowing light to shine straight out without any twisting.

The second characteristic of LCD is that it relies on polarized filters and the light itself. Natural light is scattered randomly in all directions. The polarized filters are actually a series of thinner and thinner parallel lines. These lines form a web that blocks any light rays that are not parallel to them. The polarized filter’s lines are just perpendicular to the first one, so they completely block the polarized light. Light can only pass through if the lines of the two filters are perfectly parallel, or if the light itself has been twisted to match the second polarized filter. For one thing, LCDS are made up of just such two polarized filters that are perpendicular to each other, so they should normally block any light that tries to pass through. But because the two filters are filled with twisted liquid crystals, after the light passes through the first filter, it is twisted 90 degrees by the liquid crystal molecules and finally exits through the second filter. Apply a voltage to the liquid crystal, on the other hand, and the molecules rearrange themselves to be perfectly parallel, preventing the light from twisting and thus being blocked by the second filter. In short, the electricity will block the light, no electricity will make the light. Of course, it is also possible to change the arrangement of liquid crystals in an LCD so that light is emitted when it is charged, but blocked when it is not. But because the LCD screen is almost always on, only the “power to block the light” scheme can achieve the most power saving purpose.

Active matrix LCD screen

The structure of TFT-LCD LCD is basically the same as that of TN-LCD LCD, except that the electrodes of the upper interlayer of TN-LCD are changed to FET transistors, and the lower interlayer is changed to common electrodes.

TFT-LCD liquid crystal display works differently from TN-LCD. The developing principle of TFT-LCD liquid crystal display is to use “back through” irradiation. When the light source illuminates, it first passes upward through the lower polarizer, using liquid crystal molecules to conduct light. Because the electrodes of the upper and lower interlayer are changed into the FET electrode and the common electrode, the arrangement state of the liquid crystal molecules will also change when the FET electrode is switched on, and the purpose of display can be achieved by shading and transmitting light. But the difference is that, because the FET transistor has a capacitive effect that allows it to remain in a potential state, the previously transparent liquid crystal molecules remain in that state until the FET electrodes are recharged to change their arrangement.