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What role does LCD polarizer play in LCD display screens?

Author：admin / Publication time：2021-12-17

What role does LCD polarizer play in LCD display screens?

The polarizer of an LCD screen serves as a filter for light. If there is no polarizing film on a LCD screen, there will be no display, because when the LCD screen is working, it mainly filters the light in the X or Y direction. At this time, only parallel light is available. Without polarizing film, it cannot be seen by the naked eye. Polarizing film is very thin, and if there are scratches, punctures, or abrasions, it cannot be used in production, so be careful when using it.

The function of polarizer is to play a developing role together with liquid crystal. In the production process, generally, the first step is to print two ordinary tempered glass pieces onto the circuit, apply a rubber frame around them, fold and press them in half, then inject liquid crystal in the middle of the two glass pieces, seal them above and below the glass, and attach polarizing films.

Both the upper and lower glass layers should be coated with polarizers, but pay attention to the direction. If the lower polarizer filters X-direction light, the upper layer can only filter Y-direction light. If the upper and lower layers are in the same direction, users cannot see anything. Although the LCD display is working normally, polarization cannot be seen with the naked eye. Nowadays, LCD screens usually only have an upper screen and no lower screen, which is a product of technological innovation.

Why do home display screens use polarizers?

LCD utilizes the optical rotation of liquid crystals. Liquid crystal molecules with moderate thickness can rotate the polarization direction of light by 90 ° or 270 ° (when voltage is applied, the liquid crystal molecules establish themselves due to the electric field and do not change the direction of light polarization). Adding two polarizing plates can turn the entire liquid crystal box into a single light source. One of them is a polarizer (downward tilt, close to the light source), and the other is a polarizer (close to the eyes).

If there is no polarizer, the incident light is circularly polarized, and the output light is also circularly polarized, then there is no image. It's just a white patch. As for the LCD, there is already an RGB filter film inside, but to display red, it needs to be green, blue fully turned off, and red turned on to appear red. If RGB is in a fully open state due to the failure of the polarizer, it may appear as multicolored light - white light--- Actually, you can see the condition of RGB by magnifying 10-20 times with a magnifying glass.