The first feature of the LCD screen is that the liquid crystal must fall between two flat surfaces with thin grooves to work properly. The grooves in the two planes are straight (intersecting 90 degrees to each other), that is, if the molecules in one plane are oriented north-south, and the molecules in the other plane are oriented east-west, then the molecules between the two planes will be forced to change 90 degrees. Because light travels in the direction of the molecules, the light also undergoes a 90-degree shift as it passes through the liquid crystal. But when a voltage is applied to the liquid crystal, the molecules will be placed directly from the start, so that light can be emitted directly without any change.
The second feature of LCD is that it relies on polarizing filters and the light itself. Natural light scatters randomly in all directions. A polarizing filter is actually a series of increasingly thin parallel lines. These lines form a net to block all light rays that are not parallel to these lines. The lines of the polarizing filter are aligned with the first line, so it completely blocks polarized light. Light can only penetrate if the lines of the two filters are perfectly parallel, and the light itself may have been altered to match the second polarizing filter.
An LCD consists of two polarizing filters that are perpendicular to each other, so under normal circumstances all light trying to penetrate should be blocked. However, due to the twisting of the liquid crystal between the two filters, after passing through the first filter, the light is shifted by 90 degrees by the liquid crystal molecules, and finally passes through the second filter. On the other hand, if you apply a voltage to the liquid crystal, the molecules will be perfectly parallel from the start, so the light won't change and thus be blocked by the second filter. In a nutshell, electricity blocks light, and no electricity shines. Of course, the position of the LCD in the LCD can also be changed to emit light when powered and block when not powered. But since the LCD is almost always on, only "power on" can block the light.
Under the action of the electric field, the alignment direction of the liquid crystal molecules changes, thereby changing (modulating) the transmittance of the external light source and completing the electro-optical conversion. Then, using the different excitations of the three primary color signals of r-grectorB, through the three main color filters of red, green and blue, the color reproduction in time domain and space domain different from that of the CRT color picture tube is completed. It uses digital addressing and digital signal excitation to reproduce images. The physical properties of liquid crystals are such an organic compound.
At room temperature, it shows not only the liquid fluidity of the crystal, but also the optical properties of the crystal, so it is called liquid crystal. Under the influence of external conditions such as electric field, magnetic field, temperature and stress, its molecules are easily rearranged. This makes the various optical properties of the liquid crystal change accordingly. The specificity and molecular arrangement of liquid crystals are easily controlled by external electric and magnetic fields, which are the physical basis for the formation of such liquid crystals. That is, the electro-optic effect of liquid crystal.
Light is modulated by electrical signals to create a liquid crystal display. Under the action of different currents and electric fields, the liquid crystal molecules will regularly rotate 90 degrees, resulting in different light transmittances. Therefore, when the power is turned on or off, there are different light and dark situations. According to this principle, each pixel can be controlled to form the desired image. The physical property of liquid crystals is that they turn on and are arranged in order when powered on, allowing light to pass through easily.
LCD screen display light characteristics?
2022 04/07