Polarizers - What They Are & How They Work

Liquid crystal displays use polarizers to direct the path of light so that the light is sent to the viewer’s eyes in a linear way. Natural light has transverse electromagnetic waves which cause the light to be scattered. A polarizer is a type of filter that makes the light travel though it in one linear path.

The polarizer’s duty is to take the light produced by the backlight and convert it to one singular linear light so that the notebook user can view the display.

Notebook Screen With No Polarizer

Without the polarizer, the screen would only show a white display.This is caused by the scattered light not being filtered into one uniform path.

The picture below (image A) shows a notebook LCD screen without the polarizer on it. The image is supposed to be 4 vertical columns each displaying four different colors (the image is shown in image C). The columns should display as red, green, blue and white.

Image A

As you can see, without the polarizer, the light waves are scattered and are not able to display the desired image.

Scratching and Cleaning LCD Screens

When an LCD screen is scratched, it’s not the glass that is damaged, it’s actually the polarizer. It’s a common misconception that an LCD screen’s outer surface is made of glass, that’s why so many people assume that when a screen is scratched, it’s the glass that is damaged.

This is also the reason that cleaning your screen properly is important. Many people believe that the outer layer of an LCD screen is glass and use glass cleaner to clean the screen. Harsh solvents like ammonia may damage the polarizer and cause a cloudy or distorted display. We recommend using PixelClean to ensure safe cleaning.

Repolarization

Repolarization, the act of applying a new polarizer to a notebook LCD screen, will fix any problems with a damaged polarizer. Repolarization is a difficult process that requires you to remove the old polarizer and apply a new surface.

Below is a picture (image B) of the same notebook LCD screen that was lacking the polarizer in image A. A new polarizer is being applied to the LCD screen. This process must take place in a clean room to ensure no dust or other particles get in between the glass and the polarizer.

Image B

Once the new polarizer is properly applied, the image can be viewed. Image C shows the same notebook LCD screen as in image A, but with a new polarizer applied to it. With the polarizer providing the proper filtering, you can now view the image.

Image C

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