Lab Testing Suggests Edge-Lit LCDs Win On Skinny, Lose On Longevity

August 7, 2024 by Dave Haynes

Photo from RTINGS shows IR scan of heat-generated by edge-lit LCD

The consumer product testing site RTINGs has done a deeply detailed look into edge-lit LCD displays, and found that the trade-off for a skinnier side profile than what’s possible with back-lit LCDs is longevity.

It’s important to note the displays tested were TVs not commercial displays. TVs are not designed with 16/7 or 24/7 use in mind, so the “pro” products might do better if run through the same battery of tests. However, the base observation likely applies – that LEDs generate heat and displays need to get that heat out of the enclosure.

The goal of RTINGS.com’s ongoing 100 TV longevity test is to push TVs to the limits of their durability to examine failure points as they happen. One clear trend we’ve observed and investigated is that thin, edge-lit LCD TVs fail prematurely compared to LCD TVs with other backlighting technology.

The results of this investigation are unequivocal: edge-lit TVs are inherently prone to significant durability issues, including warped reflector sheets, cracked light guide plates, and burnt-out LEDs due to concentrated heat. These problems manifest after prolonged use at maximum brightness, posing a significant risk to their long-term reliability.

This analysis, corroborated by real-world observations, highlights a crucial consideration for consumers and the industry. As manufacturers continue to push for thinner designs, addressing these durability concerns is imperative to ensure consumer satisfaction and trust. For consumers in the market for an LCD TV to whom the durability of their purchase is important, we recommend prioritizing models with better heat distribution, such as direct-lit or FALD TVs, for improved longevity and performance.

The testing team found that the heat from LED lighting arrays for direct-lit/back-lit flat panels is distributed evenly across the rare of a TV’s chassis. For edge-lit models, however, there’s a significant concentration of heat at the bottom of the screen due to the location of the LED strips.

The post gets into the technical weeds and has a pile of photos that look into what happens and why, and also shows the LCD “sandwich – the many layers that make up a liquid crystal display.

The attraction of edge-lit LCDs is their form factor – with LEDs on the edges of the display rather than a full array on the back meaning the enclosure can be skinnier. However, the differences are anywhere from a 1/4 inch to an inch. It’s not like comparing the depths of a flat panel with an old tube TV.