If you haven’t noticed, there’s a new term creeping into the television industry lexicon: Direct LED TVs. And as is so often the case, the new term has created all sorts of new confusion. Here’s a quick overview of what this means.
First and foremost, this does not refer to a TV where the image is made directly by LEDs (unlike the Sony CrystalLED technology demonstration at CES 2012). It is still an LCD TV. The difference lies in how the backlight is oriented.
LCDs don’t make an image on their own; you need to shine a light through them to be able to see the picture. Originally, LCD panels had compact fluorescent lamps (CFL) behind them to create this light. Then the cost of LEDs came down some, and manufacturers put LEDs behind the panels instead. This saved energy, eliminated the environmentally-hazardous mercury used in CFLs, and improved the color performance. It also let the backlight be dimmed in different areas, which had the effect of increasing the dynamic contrast of the screen. On the other hand, the sets cost more.
Over time, the LEDs got brighter and engineers were able to create highly efficient light guides that could distribute the light from LEDs arranged along the edge of the screen, so that it would shine evenly across the back of the LCD panel. This made it possible to create the impossibly-thin flat panel TVs that you can buy today.
The high brightness LEDs remain expensive, however, and prices continue to fall for the run-of-the-mill LEDs that are used in millions of other devices. So now manufacturers have discovered that they can use more of these cheaper LEDs arranged behind the panel, and eliminate the expensive high brightness LEDs and their sophisticated light guides. The result is a television set that is a bit thicker, but that costs less than an edge-lit LCD TV. I have not seen one yet, but I would not be surprised to learn that the “direct LED” sets are not as bright as the edge-lit models, even though they use more LEDs in the backlight.
NPD DisplaySearch sees a bright future for this design. They expect direct LED models to take more than 10% of the worldwide TV market this year, driven mostly by their cost advantage. Edge-lit models will still dominate, however, with almost 60% of the worldwide market. So if you’re price sensitive, you may want to see what sort of savings you can get — and what compromises you’ll have to accept — when the direct LED models start to appear.
(By the way, while I’m quoting NPD Displaysearch numbers, let me point out that they expect the worldwide TV market to be about 250 million units this year. Of that, they expect fewer than 50,000 units to be OLED televisions. So if you’re planning on being one of the first to get an OLED TV, be prepared to spend a lot for it, because they will be rare indeed. That’s 0.02% of the worldwide total.)
Posted by Alfred Poor, May 10, 2012 6:00 AM
About Alfred PoorAlfred Poor is a well-known display industry expert, who writes the daily HDTV Almanac. He wrote for PC Magazine for more than 20 years, and now is focusing on the home entertainment and home networking markets.