How Does an LCD Screen Work?

by Tiesha Whatley


The LCD (Liquid Crystal Display) technology has made it possible for television and computer monitors to get thinner through the years. Although the technology has been around for awhile, it has recently gained fame. Unlike its predecessor CRT (Cathode Ray Tube), LCD screens provide a brighter and higher picture quality with more mediums that is used today. LCD screens are not just used in televisions and computer monitors. Cell phones, MP3 players, and even watches use this technology. Most of the portable entertainment devices that we use today are possible because of LCD screens.

The Liquid Crystals

The liquid crystals used in LCD technology are actually made up of solid molecules that act like liquid. Unlike other solid materials, the liquid crystals have more flexibility to their movement. Not like liquid substances, the crystals also are able to remain in place. This is why some say that the liquid crystals are a comfortable medium between liquids and solids even if they are technically considered solid molecules. LCD screens are not without their limitations. The liquid crystals have high sensitivity to extreme temperatures. This, in fact, makes them unreliable in such climates.

How it Works

The secret to the wonder behind LCD screens is the placement of the liquid crystal solution between two transparent panels. The liquid crystals work together to form an image by only allowing the necessary light through. They rotate between blocking and allowing access to the light. The two panels are placed in a 90-degree angle to each other so that light can only go through one of them. They are polarized so they only pass through light waves. After electricity is supplied, the liquid crystals get in position to send the light through the 90-degree angle between the two panels. By having the crystals sandwiched between the polarized glass panels, the intensity of the light passing through is manipulated. A florescent bulb is the light source for the LCD screen. The bulb only emits a white light through the panels. By allowing all wavelengths to pass through, color is created from the full spectrum of light being manipulated. Each liquid crystal has several pixels associated with it. The pixels are what actually form images by being twisted to either block or allow light. Each pixel is then broken down into sub-pixels of red, green and blue. From these main pixel colors more than 16 million colors can be produced and shown on a LCD screen.

About the Author

Tiesha Whatley has been writing for over 10 years. She has been published in "Marie Claire," "Ebony" and "Modern Bride" magazines. She holds a Bachelor of Science in English from the University of Alabama at Birmingham and has been working in the wedding planning industry for over 13 years.

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