How Plasma TVs Work

Plasma TV technology is based loosely on the fluorescent light bulb.

• The display consists of cells.
• Within each cell, a narrow gap that contains an insulating layer, address electrode, and display electrode, separates two glass panels. In this process, neon-xenon gas is injected and sealed in plasma form during the manufacturing process.
• When a Plasma TV is in use, the gas is electrically charged at specific intervals. The charged gas then strikes red, green, and blue phosphors, creating an image on the screen.
• Each group of red, green, and blue phosphors is called a pixel (picture element — the individual red, green, and blue phosphors are called sub-pixels). Since Plasma TV pixels generate their light, they are referred to as "emissive" displays.

Plasma TVs can be made thin. However, even though the need for the bulky picture tube and electron beam scanning of those older CRT TVs is not required, Plasma TVs still employ burning phosphors to generate an image. As a result, Plasma TVs suffer from some of the drawbacks of CRT TVs, such as heat generation and possible screen burn-in of static images.

How LCD TVs Work

LCD TVs use a different technology than plasma to display images.

• LCD panels are made of two layers of transparent material, which are polarized, and are "glued" together.
• A specialized polymer that holds the liquid crystals coats one of the layers.
• Current passes through individual crystals, which allow them to pass or block light to create images.
• LCD crystals do not produce light, so they need an external source, such as fluorescent (CCFL/​HCFL) or LEDs, for the picture created by the LCD to become visible to the viewer.

Since 2014, almost all LCD TVs employ LED backlights. Since LCD crystals do not produce light, LCD TVs are referred to as "transmissive" displays.

Unlike a Plasma TV, since there are no phosphors that light up, less power is needed for operation, and the light source in an LCD TV generates less heat than a Plasma TV. There is no radiation emitted from the screen.

Advantages of Plasma Over LCD 

• Better contrast ratio and ability to display deeper blacks.
• Better color accuracy and saturation.
• Better motion tracking (little or no motion lag in fast-moving images due to Sub Field Drive Technology).
• Wider side-to-side viewing angle.

Disadvantages of Plasma vs. LCD 

• Plasma TVs are not as bright as most LCD TVs. They perform better in a dimly lit or darkened room.
• The screen surface is more reflective than most LCD TVs, which means they are susceptible to glare — screen surface reflects ambient light sources.
• Plasma TVs are more vulnerable to burn-in of static images. However, this problem diminished over the years due to "pixel orbiting" and related technologies.
• Plasma TVs generate more heat and use more energy than LCD TVs, due to the need to light phosphors to create images.
• Plasma TVs do not perform as well at higher altitudes.
• Potentially shorter display lifespan. Early models had 30,000 hours or 8 hours of viewing a day for nine years, which was less than LCD. However, screen lifespan improved and 60,000-hour lifespan rating became the standard, with some sets rated as high as 100,000 hours, due to technology improvements.