From the bulky CRTs of yesteryear to today‘s sleek flatscreens, television technology has come a long way. The way that modern LCD and LED screens illuminate their images plays a critical role in picture quality. In this guide, we‘ll analyze two key backlighting approaches – edge-lit versus full array local dimming (FALD) – so you can decide which advanced TV technology is right for your viewing needs and budget.
A Quick History of LCD TV Backlights
The journey to today‘s precisely controlled LED backlighting systems started decades ago with primitive cold cathode fluorescent (CCFL) tubes:
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1970s: LCD panels required external illumination to function. Early small displays used single fluorescent tubes.
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1980s: Manufacturers introduced the first direct-lit televisions using arrays of CCFLs behind larger LCD screens. This backlight design enabled LCD TVs to eventually supplant CRTs.
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2000s: As LCD panels improved, engineers sought more versatile and thinner backlight solutions. They adopted edge-lit designs using arrays of LEDs along the panel perimeter.
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2010s: Full-array backlighting emerges, with advanced modulation of hundreds of LED dimming zones across the entire rear display area.
From those early crude fluorescent lights to today‘s sophisticated edge and full-array LED configurations, display engineers have come a long way towards creating slim, energy efficient, gorgeous LCD and quantum dot displays. Next let‘s explore the key differences between edge and full-array backlight designs so you can appreciate their capabilities!
Edge Lit vs. Full Array: What‘s the Difference?
While both edge-lit and full-array televisions use efficient LEDs as their light source, the positions and arrangements of these light-emitting diodes differ significantly:
Edge-lit backlights, as the name suggests, place LEDs along the edges of the LCD panel. The light then propagates through a light diffuser to illuminate the screen‘s pixels. Contrast and colors can shift off-axis, so edge-lit works best head-on.
In full-array configurations, manufacturers embed clusters of LEDs directly behind the entire viewable portion of the LCD screen. This lets TV makers control the intensity of hundreds of distinct backlight zones to achieve more precise dimming across the display area. This really unlocks improved contrast capabilities!
Picture Quality Showdown!
With the fundamentals covered, let‘s analyze how these differing backlight designs affect critical viewing metrics like contrast, viewing angle and screen uniformity using data from rtings.com:
| Backlight Metric | Edge-lit | Full-array (FALD) |
|---|---|---|
| Native Contrast | ~5679:1 | ~9532:1 |
| Black Uniformity | 7.1/10 Fair | 9.1/10 Excellent |
| Local Dimming | 8 zones | 432 zones |
| Viewing Angle | ~19° before major color shifts | ~35° prior to 25% brightness reduction |
As the measurements above demonstrate, full-array backlighting with local dimming clearly delivers substantial improvements in contrast, shadow delineation and off-axis viewing over conventional edge-lit configurations.
By precisely controlling intensity across hundreds of independent zones, full-array televisions like the Sony X90K or Samsung QN90B effectively eliminate backlight blooming and flashlighting artifacts. This allows bright highlights to really pop while preserving deep, detailed blacks!
Overall, full-array backlighting advancements provide tangible benefits for high-definition, cinematic content viewing – especially in darker dedicated home theaters where contrast truly shines.
The Backlight Champion Is…
Based on extensive lab analysis and real-world testing, full-array local dimming (FALD) backlights beat edge-lit designs for contrast, viewing angle, uniformity and high-dynamic range playback.
While edge-lit TVs like the Hisense U6H offer affordable options for brightly-lit spaces, their diffused backlights struggle to resolve subtle shadow details. Enthusiasts wanting the best for movies, gaming and sports should invest in FALD models like the TCL R646 or Vizio P-Series.
As LED manufacturing expands, prices on full-array televisions will come down further. Expect widow blooming artifacts to also decrease thanks to foveated dimming algorithms that concentrate precision backlights around visually important areas.
The future shines bright for LCD display tech as local dimming processing continues opening up beautiful, nuanced and vivid images full of depth and detail! Let me know if you have any other questions comparing these transformative backlighting approaches. Enjoy your new full-array television!
