When it comes to understanding the difference between LED TVs and LCD TVs, the term “LED TV” is kind of a misnomer. So-called LED TVs and LCD TVs both use liquid crystal display (LCD) technology to create the picture—the difference is in the backlight. Your typical LCD TV is backlit by compact fluorescent lighting (just like those earth-friendly CFL bulbs), while an LED TV is lit by LED (light emitting diode) lights (like in stoplights and automotive lights).
Among LED backlit televisions, there are two types of arrangements: edge lighting, which puts LEDs around the edge of the display for thinner construction and full array, where the LEDs are placed behind the screen. Both edge-lit and local array LED backlights can also come with local dimming, which allows the individual LEDs to dim or brighten independently to create higher contrast. Virtually all full array LED TVs have local dimming, and in general, these provide the best picture. Edge-lit LED TVs without local dimming are the most common LED TV.
So, for comparison purposes, you’re looking at three main types of LCD TV backlights: fluorescent (the standard LCD TV), edge-lit LED (usually without local dimming) and full array LED (with local dimming). Here’s how they stack up:
Contrast is all about accentuating the differences between dark and light spaces, so naturally, full array with local dimming works the best. Edge-lit LEDs and more recent fluorescent backlit LCDs are tied for second.
LED TVs can come with white LED backlights or RGB LED backlights. In terms of color accuracy, you won’t notice much of an improvement over fluorescent LCDs in a LED TV with white LED backlights. But an LED TV with RGB backlights provides much better color accuracy.
Viewing angle refers to the clarity of the picture when viewed from the side or from above or below. In general, full array LED TVs with local dimming perform the best, followed by fluorescent LCD TVs and then edge-lit LED TVs. However, a bigger factor is the quality of the glass and any anti-glare features it may have. Higher end TVs will have better viewing angles, simply by virtue of having higher quality parts, in theory.
Refresh Rates and Response Time
The way that TVs handle action and fast movements, such as in action flicks, sports broadcasts and video games, depends on the response time (measured in milliseconds) and the refresh rate (measured in hertz). Backlight technology—such as LED vs. fluorescent—has no bearing on response time or refresh rate, so you won’t see any improvement in capturing action with an LED TV.
For those of you concerned about going green, your best bet is an edge-lit LED. LEDs consume less energy than fluorescent bulbs. However, full array LEDs with local dimming use far more individual LEDs than edge-lit LED TVs, and for now, full array LED TVs consume more energy than fluorescent LCDs.
LED TVS are better than LCD TVs in many ways, but don’t focus solely on the backlighting technology. Not all LED TVs are created equally, and a high end LCD TV just might outperform an LED in some crucial departments. Your best bet: comparing them with your own eyes without looking at the specs and decide which you like the most.