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LED TVs: What Are They Really?

May 29, 2009 | Author: Ibex Marketing

I’ll blame Samsung. Not their engineers who develop some great technology, and not their manufacturing people who execute those designs to create top quality products, but I expect that it’s the marketing folks who came up with this one. There’s a lot of buzz about “LED TVs“, which appears to be a term that Samsung started using first. And it apparently has confused and misled a huge number of people, convincing many of them that this is a new display technology. It’s not.

Let’s review. For flat panels televisions, there are only three technologies that are in commercial production, and I’m being generous with one of them. The hands-down leader is LCD, with plasma following a distant second. OLED doesn’t even show up on the pie chart, because Sony’s little non-HD jewel is the only one on the market (ignoring any mobile phones that can be used to watch TV content). LCD technology uses liquid crystal molecules like tiny shutters to transmit or block light from a backlight. Plasma uses a process similar to a fluorescent light to light up colored phosphors that emit the light that makes up the image. OLED stands for “organic light emitting diode (or display)” and is an amazingly thin device that can emit light of different colors when you run an electrical current through it. (It’s sort of the reverse of a solar cell, which takes in light and puts out electricity.) People are rightfully excited about OLED TVs because the color can be excellent and the incredibly deep black of the image creates outstanding contrast. It’s not clear when we’ll see OLED TVs in reasonable sizes at affordable prices, though some expect to see new products in this segment by the end of this year.

However, LED TVs are not OLED TVs. They are LCD TVs, and for the most part are little different from any other LCD TV that has been on the market. An LED is a solid state lighting device that generally creates a point of light. They are very energy efficient, and every power indicator you have on any electronic device is almost certainly an LED.

What Samsung has done — along with many other companies — is replace the fluorescent backlights on an LCD TV with LEDs. This has a number of advantages. LEDS can make the device more energy efficient, use less environmentally hazardous material, and generally provide a richer color response for the display. As I’ve discussed here before, LEDs also give designers the choice of putting the backlight source either behind the LCD panel or off along the edges of the panel. Positioned in back, they make it possible to do localized dimming which can increase contrast. Positioned along the edge, they can result in a much thinner LCD TV.

So an LED TV is just an LCD TV with an LED backlight. This reminds me of when the rear projection TV makers tried to come up with other names for their product category (such as Mitsubishi’s “Laser TV”) in an attempt to make them more appealing and sound new. And apparently it is working, which is a shame because many people think that the image is being made by LEDs, and is different from an LCD TV. The only true LED TVs that I know of are some of the giant stadium displays that use clusters of LEDs to create the image, but you won’t find anything like that in a room-sized flat panel TV.

Spread the word.