The Difference Between an LCD TV and a Plasma TV

LCD and Plasma TVs look similar on the outside, but are different on the inside

Young Couple Checking TV - LCD vs Plasma
Young Couple Checking TV - LCD vs Plasma.  Getty Images - Cultura Collecton - Raygun - 102761530 

In 2015, Plasma TV production was discontinued. However, many are still being used and sold in the secondary market. As a result, understanding how a Plasma TV works and how it compares to an LCD TV is important.

Plasma and LCD TV: The Same, But Different

Outward appearances are definitely deceiving when it comes to LCD and Plasma TVs.

Plasma and LCD TVs are flat and thin, and may also incorporate many of the same features. Both types can be wall mounted and may offer the internet and local network streaming, both offer up the same types of physical connectivity options, and, of course, both allow you to watch TV programs, movies, and other content in a variety of screen sizes and resolutions. However, how they produce and display those images is actually quite different.

How Plasma TVs Work

Plasma TV technology is based loosely on the fluorescent light bulb. The display itself consists of cells. Within each cell two glass panels are separated by a narrow gap in that includes an insulating layer, address electrode, and display electrode, in which 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, thus creating an image on the Plasma TV screen. Each group of red, green, and blue phosphors is called a pixel (picture element - the individual red, green, and blue phosphors are referred to as sub-pixels). Since Plasma TV pixels generate their own light, they are referred to as "emissive" displays.

Due to the way that a Plasma TV works, it can be made very thin. However, even though need for the bulky picture tube and electron beam scanning of those older CRT TVs is no longer required, Plasma TVs still employ the burning phosphors to generate an image. As a result, Plasma TVs still suffer from some of the drawbacks of traditional 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 image. LCD panels are made of two layers of transparent material, which are polarized, and are "glued" together. One of the layers is coated with a special polymer that holds the individual liquid crystals. Current is then passed through individual crystals, which allow the crystals to pass or block light to create images.

LCD crystals do not produce their own light, so an external light source, such as fluorescent (CCFL/​HCFL) or LEDs are needed for the image 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 their own 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. Also, because of the nature of LCD technology, there is no radiation emitted from the screen itself.

ADVANTAGES of Plasma over LCD 

  • Better contrast ratio and ability to render deeper blacks.
  • Better color accuracy and saturation.
  • Better motion tracking (little or no motion lag in fast moving images due to the use of 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. Plasma TVs perform better in a dimly lit or darkened room.
  • Screen surface is more reflective than most LCD TVs. More susceptible to glare - screen surface reflects ambient light sources.
  • Plasma TVs are more susceptible to burn-in of static images. However, this problem has diminished greatly in recent years as a result of the incorporation "pixel orbiting" and related technologies.
  • Plasma TVs generate more heat and use more energy than LCD TVs, due to the need to light of phosphors to create the images.
  • Does not perform as well at higher altitudes.
  • Potentially shorter display lifespan - this used to be the case. Early Plasmas had 30,000 hours or 8 hrs of viewing a day for 9 years, which was less than LCD. However, screen lifespan has now improved and 60,000-hour lifespan rating is now common, with some sets rated as high as 100,000 hours, due to technology improvements.

ADVANTAGES LCD over Plasma TV

  • No burn-in of static images.
  • Cooler running temperature.
  • No high altitude use issues.
  • Increased image brightness over Plasma, which makes LCD TVs better for viewing in brightly lit rooms.
  • Screen surface on most LCD TVs is less reflective than Plasma TV screen surfaces, making it less susceptible to screen glare.
  • Lighter weight (when comparing same screen sizes) than Plasma counterparts.
  • Longer display life, but the gap has narrowed.
  • For 3D, with LCD you have a choice between units that use Active Shutter and Passive Glasses, whereas 3D Plasma TVs only utilize the Active Shutter Glasses system.

DISADVANTAGES of LCD vs Plasma TV:

  • Lower real contrast ratio, not as good rendering deep blacks, although the increasing incorporation of ​LED backlighting has narrowed this gap.
  • Not as good at tracking motion (fast moving objects may exhibit lag artifacts) - However, this is improving with the recent implementation of 120Hz screen refresh rates and 240Hz processing in most LCD sets, but that can result in the "Soap Opera Effect", in which film-based content sources look more like videotape that film.
  • Narrower effective side-to-side viewing angle than Plasma. On LCD TVs, it is common to notice color fading or color shifting as you move your viewing position further to either side of the center point.
  • Although LCD TVs do not suffer from burn-in susceptibility, it is possible that individual pixels on LCD televisions can burn out, causing small, visible, black or white dots to appear on the screen. Individual pixels cannot be repaired, the whole screen would need to be replaced at that point if the individual pixel burnout becomes annoying to you.
  • LCD TV is typically more expensive than equivalent-sized (and equivalent featured) Plasma TV, although that is no longer a factor, now that Plasma TVs have been discontinued.

The 4K Factor

One additional thing to point out with regards to the difference between LCD and Plasma TVs, is that when 4K Ultra HD TVs were introduced, TV manufacturers made the choice to only make 4K resolution available on LCD TVs, using LED back and edge-lighting, and, in the case of LG and Sony, also incorporating 4K into TVs using OLED technology.

Although it is technologically possible to manufacture and incorporate 4K resolution display capability into a Plasma TV, it is more expensive to do so than on an LCD TV platform, and, with the sales of Plasma TVs continuing to decline over the years, Plasma TV makers made a business decision not to bring consumer-based 4K Ultra HD Plasma TVs to market, which was another factor in their demise. The only 4K Ultra HD Plasma TVs that were/are manufactured are strictly for commercial application use.

The Bottom Line

Plasma has a distinguished place in TV history as the technology that started the trend towards the flat panel, hang-on-the-wall TV, and video display device that was promised since the early 1950's. Developed over 50 years ago, its practicality and popularity peaked in the first decade of the 21st century but has now passed onto Gadget Heaven as a result of advancements in LCD TV technology and the introduction of OLED TVs, which have closed the gap with some of the advantages that Plasma TV offered.

For a more detailed look at the LCD and Plasma TV comparison, also read: Should I Buy an LCD or Plasma TV?.