Power consumption on LCD TVs drops with new film

Chemical giant 3M says it can save the world 33 million barrels of oil, if LCD TV manufacturers adopt a new film it has created.

The company's Vikuiti Dual Brightness Enhancement Film D400, or DBEF D400, can cut power consumption in liquid-crystal display TVs by 20 to 30 percent without dropping brightness or picture quality, said Dave Iverson, business manager for LCD TVs at 3M, who spoke at the Society for Information Display conference here.

On an individual TV turned on four hours a day, a TV with DBEF D400 will use about 36.5 kilowatt-hours less per year than a standard LCD TV, Iverson said Wednesday. Over five years, that turns into 182.5 kilowatt-hours.

"This offers a proven way for manufacturers to meet increased demands for energy efficiency," he said.

Because TV manufacturers can put fewer bulbs inside these TVs, adding the film doesn't add costs, Iverson claimed. The savings from using fewer bulbs and other components to run these TVs can roughly equal the cost of the new film.
"We want this to be cost-neutral," he said.

DBEF D400 essentially recycles light. In LCD TVs, a series of light bulbs or LEDs are aimed at a polarizer. The polarizer absorbs about half the light. The remaining light then goes to a layer of LCD pixels and the light passes through another polarizer. Although the polarizers block light, they also manipulate light to create images. Without them, watching LCD TVs would be similar to staring at a light bulb.

The DBEF layer sits behind the first polarizer and bounces unused light back into the system. Thus, depending on how many bulbs are removed, an LCD TV with the material can provide a similar image using less energy, or a higher brightness with slightly less power saving.
In comparisons provided by 3M, a standard 37-inch LCD comes with 16 bulbs. The TV will consume 180 watts and sport an internal cavity temperature of 65.9 degrees Celsius. At roughly the same level of brightness, a DBEF D400 TV will run at 145 watts, 35 watts less, and come with a cavity temperature of 56.2 degrees Celsius.

Those watts add up. Over the next five years, an estimated 315 million LCD TVs measuring 21 inches and above will leave factories, Iverson said. Assuming DBEF D400 will save an average of 25 watts on each TV, the material will save 57.5 billion kilowatt hours worldwide over five years, if these TVs are watched on average for four hours a day (315 million TVs by 182.5 kilowatt hours per TV over five years).

That translates to 33 million barrels of oil or 23 million tons of coal.
Iverson did not say when TVs with the material would start coming out, but he indicated that it might be soon. 3M has worked with cell phone manufacturers and notebook makers on screens for several years.

"TV is a natural extension of our business," he said. "We've been in visual enhancement for a long time."

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