The television you purchase today will likely get used for several hours a day for many years into the future. Given that stare time, ensuring that TV delivers an immersive viewing experience directly tied to your preferences becomes paramount.
But mapping personal taste onto the dizzying specifications slapped onto boxes at the electronics store proves no easy task. Competing manufacturers don‘t exactly help the situation, hawking proprietary technologies that often confuse more than clarify.
Cutting straight through the layers of jargon and hype, the single most important yet often overlooked factor that dictates picture enjoyment remains the TV‘s backlight system shining behind the screen. Let‘s discover why backlight tech matters so much along with the key options available today.
What is a TV Backlight and Why Does it Matter?
The term itself provides a hint – the backlight refers to light source positioned behind the screen directing illumination forward. But why would screens need dedicated backlights in the first place?
The answer traces to the origins of the ubiquitous LCD panels found in virtually every flat panel television today. LCD stands for liquid crystal display, first tinkered with in the late 1800s and ultimately perfected to enable mass market adoption.
Without diving too deep into technical minutia, the liquid crystal molecules lining every pixel act like tiny shutters able to manipulate light by twisting to varying degrees when zapped with electricity. The crystals themselves emit no light.
For this reason, engineers ingeniously decided to place a bright white light source behind the panel to provide the crucial illumination, birthing the concept of the modern television backlight.
LED backlights beam light through the LCD panel to produce TV images
Nowadays advanced display engineering concentrates around crafting ever more precise and power efficient backlight systems to unlock optimal viewing. The journey has taken us from bulky CCFL tubes to slender LED strips and beyond, but the mission remains providing the LCD panel enough uniform light to sufficiently render on-screen content without artifacts, dimming or distortion.
The right backlight empowers your TV. The wrong backlight sabotages even the most premium processor and pixel density. Let‘s uncover which approach works best for you.
LCD TV Backlight Breakdown: The Full Spectrum
We can bifurcate current LCD TV backlight solutions into two overarching designs – edge-lit, where LEDs line just the edges, or direct-lit with LEDs behind the entire screen area. Within these two buckets exist several sub-flavors with their own pros, cons and custom terminology TV makers have assigned. Let‘s sort them out.
| Backlight Design | Description |
|---|---|
| Edge-lit | Entry-level option with LEDs along 1-4 edges shooting inward |
| – Standard dynamic backlight | Basic implementation, usually just bottom edge |
| -Local dimming | Bases backlight adjustment on image area data |
| Direct-lit | LEDs cover entire rear area for pixel-by-pixel control |
| – Full array standard | LEDs remain always on with global brightness adjustment only |
| – Full array local dimming (FALD) | Rear LED zones dim independently based on picture content |
| – Quantum dot enhancement film | Nanocrystal layer sharpens color and brightness |
This table highlights key backlight capabilities that influence your viewing experience. Edge lighting beams inward sacrificing light control while direct rear LED placement bolsters contrast with dimming finesse.
Now let‘s explore the unique pros and cons around these designs so you can match your preference to the optimal display architecture.
Quick Backlight Tech Glossary
- LED – Light Emitting Diode, refers to thin backlight components
- CCFL – Cold Cathode Fluorescent Lamps, older backlight tech
- FALD – Full Array Local Dimming, the most advanced LED LCD backlight
- OLED – Organic Light Emitting Diode, self-emissive display without backlight
Edge-Lit LED TV Backlights – An Affordable Option
Edge lighting saves cost by placing LEDs only along the monitor‘s perimeter
As the name suggests, edge-lit LED backlights position slender LED strips along the edges, most commonly just the bottom. To spread this light out evenly behind the LCD panel, display engineers utilize light-guide plates made of specialized acrylic plastic. These plates act like high tech mirrors propagating inward illumination.
Such minimal LED positioning around merely one edge significantly slashes manufacturing expenses, enabling edge-lit TV offerings at lower price points. And thanks to quality light guiding methods, illumination uniformity proves decent with most content types.
The Pitfalls of Edge Lighting
Cost savings don‘t come free, however. Pumping light inward from the edges forces engineers to max out backlight brightness to compensate for attenuation toward the center, compromising contrast and black levels. Blooming and flashing may accompany stark light-to-dark transitions.
TV makers do implement edge dimming with extra LED zones, but without rear access this requires elaborate heat dissipation and offers only minor picture improvements. For these reasons, cinema purists and videophiles favor direct backlight options.
Direct-Lit LCD TV Backlights – The Full Monty
Rather than relegating tiny LEDs to the edges, direct-lit backlight arrangements utilize LED strips right behind the entire screen area for pixel-level illumination precision. This rear access also facilitates much higher overall brightness.
Earlier implementations suffered deficiencies from simply bathing the LCD matrix in continual bright light. But by partitioning the rear LED layers into zones addressable independently, display engineers grant direct-lit architectures unprecedented dimming capabilities.
The industry refers to these segmented direct-lit LED backlights by the terminology full array local dimming (FALD). The "local" indicates control at a regional instead of global scale. The more zones, the finer and more accurate the algorithmic light modulation.
Full Array Local Dimming Demystified
The "full array" descriptor specifically distinguishes how the LEDs stretch across the complete rear rather than merely along edges like older direct-lit approaches. This grants superior uniformity, blacks and brightness but costs more.
Partitioning the rear LED layer into individual zones then enables independent on/off control over these localized areas. By selectively dimming zones displaying darker picture content, TVs produce enhanced contrast and shadow detail. Bright zones punch brighter simultaneously.
Zonal LED control behind the panel boosts dynamic range and picture realism
Quantum Dots & Phosphors – Maximizing Color Quality
Many higher-end LCD televisions tout proprietary sounding technologies like Samsung‘s QLED points or LG‘s Nanocell. Marketing speak aside, these all describe additional layers sandwiched within the panel to amplify color quality and gamut performance.
Quantum dots consist of tiny semiconductor nanocrystals 10,000 times smaller than a human hair. Their composition allows pure color emission when excited by light. Red quantum dots radiate only a tight red band when stimulated, with no bleed into oranges or crimsons.
This spectral purity proves superior to white LED and color filter methods. Introducing a quantum dot enhancement film between backlight and LCD grants LED TVs ability to render over a billion color combinations with extreme accuracy across 94% of the strict DCI-P3 color space required for cinema.
Beyond quantum tech, traditional color phosphors painted onto the LED emitters themselves allow similar color refinement albeit via a different mechanism. Combining either technique with full array local dimming unlocks exceptional LCD performance almost matching self-emissive OLED displays.
OLED Displays – Lighting the Way Forward
We‘ve explored at length how LCD panels utilize ever-evolving backlight solutions to illuminate their liquid crystals. This innate dependency on an external light source in a sense restricts ultimate imaging fidelity. Since crystals merely filter instead of generate light, even the most precise backlights fail delivering perfection.
This limiter has sparked extensive commercialization efforts around OLED displays – OLED standing for organic light emitting diode. These panels eschew liquid crystals entirely and instead utilize electroluminescent films made from organic carbon/hydrogen compounds that glow when zapped with electricity.
In other words, each self-illuminating OLED pixel produces its own light. This eliminates any need for a backlight and accompanying imperfections. OLED TVs toggle pixels rapidly from absolutely black to eye-searingly bright with no distortions in-between.
OLED pixels switch on/off themselves without needing backlights
Commercially available OLED TVs still can‘t match the peak brightness ceilings of quantum-dot enhanced LCD options. But many home theater fans happily exchange a bit less pop for flawless blacks and color accuracy. OLED continues marching down cost curves as well, making this backlight-free alternative ever more viable.
And waiting in the wings, microLED technology seeking to combine the self-emissive advantages of OLED with the brightness headroom of LCD threatens to make backlights entirely obsolete further down the road. But for now discerning shoppers still have some solid options to weigh.
Evaluating Your Backlight – Matching Tech to Taste
We‘ve covered a wide span of backlight designs powering LCD televisions today along with the rapidly evolving OLED alternative. But with so many choices on the market right now claiming "best" status, how do you approach matching technology to your taste and room? Let‘s simplify a bit.
For buyers wanting absolute peak brightness to overpower ambient room lighting during daylight viewing, full array local dimming LED-LCD TVs augmented by quantum dots currently claim the luminance crown. Samsung QLED models starring in showrooms push over 2,000 nits!
If watching movies in darker rooms ranks higher among your needs, OLED offers unrivaled contrast and shadow detail thanks to pixel-perfect black levels and precision color rendered without filtering. LG‘s newest OLED Evo Gallery Series astounds.
And finally, consider your budget restraints. Quality edge-lit LED televisions containing decent local dimming from trusted brands still provide excellent performance for their affordable pricing. As long as you temper expectations, edge-lit solutions warrant consideration for their value.
At the end of the long day, selecting a personalized perfect TV backlight remains paramount. But arm yourself with the background above to slice through flashy buzzwords and instead scrutinize how lighting design maps to your use cases. Backlight first when television shopping. Because behind every great TV, beams an even better backlight.
