A flat-screen television is now accepted as the standard hardware for visual entertainment. Behind the sleek lines and minimalist proportions are remarkable technology and electronic engineering. The backlighting of your screen, in particular, can transform the intensity and contrast of colors for an exceptional viewing experience. 

There is a wide range of backlighting options for the LCD technology that is commonly used in TV screens. Common backlighting solutions include:

  • Light-emitting diodes (LED)
  • Electroluminescence panels (ELP)
  • Cathode fluorescent lamps (Hot CFL)
  • Cathode fluorescent lamps (Cold CFL)
  • Incandescent light bulbs

But, it’s not just the type of backlighting that’s important, the arrangement of the lights matters too. This is because the lighting arrangement and distribution determine how light is directed into the color filters and other critical layers of the screen. Two of the leading options are edge-lit and full-array. 

Let’s draw an in-depth comparison of edge-lit and full-array backlighting to help you evaluate which technology is best for your viewing needs.

What is Edge-Lit?

Edge-lit screen backlighting is used to backlight an LED screen using LEDs to line the edges of the screen. Manufacturers place the LEDs along the top and bottom of the screen or right around the perimeter. A stiff piece of opaque plastic called a diffuser can then distribute the light across the screen. 

Edge-lit screens differ from conventional LED screens as the backlighting does not originate directly behind the screen. It, therefore, has a more muted effect and the potential to introduce greater contrast into the images that are displayed. 

Edge-Lit Screens Provide Focused Lighting

Edge-lit screens have more backlighting control than a basic uniform backlight, as individual LEDs can be brightened or dimmed to create focused backlighting in harmony with the screened content. Edge-lit LCD screen light achieves this by:

  1. The creation of up to 12 dimming zones made up of vertical bands that are created by brightening or dimming LED at the top or bottom edge of the screen.
  2. Independent dimming of top and bottom edge LEDs to create a greater number of targeted dimming zones. 

Edge-lit dimming is generalized and diffused. This limits high dynamic range imaging and creates phenomena like haloing because of unwanted illumination of certain parts of the screen.

What is Full-Array?

Full-array, or full-array with local dimming (FALD), is an alternative backlighting technology that uses numerous individual LEDs distributed across the back of the screen. It is a newer and more refined backlighting technology when compared to an edge-lit screen. 

The use of LEDs that are distributed across the screen area means that manufacturers can break the backlighting up into multiple localized dimming zones. Each zone can be individually brightened or dimmed to create an illuminated color that is in harmony with the displayed images. In particular, dark sections of the screen are more distinct, avoiding elevated black levels.

This local, more dynamic backlighting produces deeper colors and richer images because of the fine control of the backlighting. It enhances the display of HDR content and minimizes blooms or haloing. This is because FALD provides greater contrast than other forms of backlighting. This vivid display technology is now adopted by LCD/LED screens across all price points, though the more expensive screens have a greater number of dimming zones and match the images more precisely. 

Edge-Lit vs. Full-Array: A Side-by-Side Comparison

Edge-LitFull Array
What is it?A backlight panel arrangementA backlight panel arrangement
Primary UseLighting for an LED-backlit LCD screenLighting for an LED-backlit LCD screen 
Conceived1980s 2000s 
Initial ReleaseLate 1990s2012
Technical CommitteeSamsungSony, LG, Samsung
Influential DevelopersSamsungSony, LG, Samsung
Open FormatYesYes
Technologies InfluencedTelevisions, desktops, monitors, laptopsTelevisions, monitors, laptops
LED TV
While edge-lit and full-array are both backlighting technologies, they certainly have their differences!

The Differences Between Edge-Lit and Full-Array

Edge-lit and FALD provide the illumination necessary to view images displayed on an LCD screen. However, these two types of backlighting differ significantly in the arrangement of their LEDs, the degree of contrast they provide, and their ability to support HDR imaging. 

Edge-lit screens have their backlighting around the edges of the screen while Full Array screens have LEDs across the back of the screen which can be illuminated in several localized zones.

Edge-lit screens were one of the first generation backlighting technologies. But the earliest screens were affected by hotspots and the lighting achieved was eventually perceived as inadequate, However, as LED technology advanced and could provide move nuanced lighting effects, Edge-lighting was revisited by Samsung who released a market-leading edge-lit LED television in 2009.

Full Array screens are much more sophisticated and use an array of LEDs to provide targeted illumination across an entire LCD panel. This more advanced technology achieves greater contrast than Edge-Lit screens across a wider range of viewing angles and depicts colors more accurately this has led to FALD superseding edge-lit lighting. 

Pros and Cons of Edge-Lit

ProsCons
AffordableNo precision dimming
Compact, thin screenNarrower viewing angle
Energy-efficientVariable image quality
Can dim the screen in sectionsLess contrast than full-array
LightweightElevated black levels
Potential for screen burn-in
Local dimming is less marked than full-array

Pros and Cons of Full-Array

ProsCons
Better picture qualityGreater power consumption
Better representation of HDR imagesMore expensive to buy and run
Increased contrast and true blacksPotential for screen burn
Wider viewing anglesCan cause screen burn-in 
More targeted illuminationA single failed LED can cause the entire backlight to fail

Edge-Lit vs. Full-Array: 6 Must-Know Facts

  • Just one LED can illuminate 1,400 pixels of an LCD screen.
  • Samsung pioneered edge-lit technology, launching the world’s first edge-lit TV in 2009.
  • There can be 1,500 LEDs in a backlighting array for a 1,080-pixel TV. These can illuminate over 2 million pixels.
  • The localized dimming of FALD introduced an exceptional level of contrast. 
  • Full-array backlit screens can adapt the localized lighting to the content that is being displayed.
  • Edge-lit backlighting can make dark or black areas of the screen appear gray. 

Final Thoughts

Your choice of flat-screen backlighting can really affect the quality of your viewing experience. Edge-lit screens are a mature technology that is affordable and energy-efficient.

But, for a cutting-edge viewing experience, full-array LED backlighting provides more accurately rendered color with the contrast that high-definition images require.

Edge-Lit vs. Full-Array: Which Option Delivers Better Contrast? FAQs (Frequently Asked Questions) 

What is the contrast ratio of a TV screen?

The contrast ratio compares the brightest white rendered on a screen with its darkest black. You can calculate it using a checkerboard test pattern on the screen with the brightness of the white squares divided by the darkness of the blacks. Ratios of over 3,000 provide the best viewing quality.

What is black crush?

Black crush is a loss of detail or distinction of shadows in images on the television screen. The dimming algorithm that the screen uses, which prioritizes black rather than darker tones and grays, causes the loss of detail. Black crush may not be apparent until you view the images on a screen with better contrast and controlled rendering of dark colors.

What is screen burn-in?

The intense backlighting of some plasma, OLED, and LED televisions causes screen burn-in, leaving a mark that remains faintly visible in other screened images. This phenomenon can be created by leaving bright static images on the screen for a prolonged period. You cannot repair screen burn-in, but you can lessen its prominence by adjusting the screen brightness of the display.

What is blooming?

Blooming is a halo effect seen around certain bright objects displayed on the screen. Light bleeding from the bright object causes this in darker parts of the image. FALD can cause blooming.

What is the best backlight type?

FALD is the most advanced type of backlighting. It has a more extensive array of LEDs covering the entire screen area and achieves highly localized dimming in accordance with sophisticated algorithms designed by the manufacturer to support contemporary television viewing. This enables it to support HDR imaging with greater contrast and delivers excellent viewing quality.

What is the viewing angle of a screen?

The viewing angle is the range of angles where you can view an image on a flat-screen TV. For all flat-screen TVs, viewing the center of the screen displays the best image, but some screens have a narrower viewing angle than others. More controlled backlighting, like FALD, can improve color consistency when you view images through a range of viewing angles.

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