Yesterday, a funny thing happened. My child accidentally removed the protective film (probably not a protective film, or something else entirely) from the outermost part of our TV monitor. The part that was removed no longer displayed the image, while the other part displayed normally. The child then removed it and stuck it back together.
Eventually, he removed the protective film and stuck it on his glasses, but the image became blurry and unclear. What's the reason for this?
LCD panels have two polarizers, one with a vertical polarization direction and the other with a horizontal polarization direction.
When electricity is applied to the electrodes, the liquid crystal molecules align under the control of the electrodes, and the polarization direction of the light no longer rotates. Polarizers, also called polarizing filters, change the polarization direction of light. The backlight emits natural light, which is converted to linearly polarized light by the lower polarizer. Different voltages are used to control the twist angle of the liquid crystal molecules, thereby rotating the polarization direction of the incident polarized light. The upper polarizer acts as a light filter, filtering light with a consistent polarization direction and blocking light with an inconsistent polarization direction, which appears dark and forms an image. The amount of light that passes through a polarizing filter determines the brightness of the image. Without a polarizing filter, the light won't be filtered, resulting in blurry or no display. This is why LCD screens require polarizing filters. Furthermore, the angle of the polarizing filter also affects image clarity.
