PLEXIGLAS® for super-flat televisions with a sharp picture
TVs became more flat through LED edge lighting with PLEXIGLAS® light guides
No diffusion or absorption losses
30 percent lower electricity consumption per television due to energy-efficient backlighting
Televisions are becoming ever flatter and more energy-saving. PLEXIGLAS® POQ66 was specially developed for these applications.
Energy efficiency with a flat design
The specialty product from Evonik shows particularly high light transmission combined with a low refractive index, making it the ideal material for manufacturing light guides. This makes it especially suitable for LCD televisions that have an edge-lit backlight unit. With this, LEDs feed light into a light guide plate via the edges. This provides uniform backlighting of the display. The plate is the central element of the backlight unit, and means that televisions can be made flatter and more attractive. At the same time, they save electricity because they use LEDs instead of cold-cathode fluorescent lamps (CCFLs), and need less LEDs than direct backlighting modules. What’s more, with light guide plates made of PLEXIGLAS® POQ66, no light is lost by absorption or diffusion.
"Light guide plates for this application can only be made from PMMA, because of the required material properties," says Dr. Alexander Baum, Manager of the Optically Functional Materials Segment, Business Development at Acrylic Polymers.
"Only this highly transparent material enables the manufacture of edge-lit LED backlight units, which are much more energy-efficient than the previous technology." This is mainly due to the material’s high transmission. "In addition, PLEXIGLAS® has the lowest refractive index (1.49) of all commercially available transparent plastics. The Fresnel reflection upon entry into the light guide plate is only 3.8 percent," says Baum.
The material also has to remain transparent in the long term so as not to distort color rendition. Some plastics turn yellow over the years and the picture suffers in consequence. As a neutral-colored material, PMMA has no negative influence on colors, and therefore provides durably natural rendition.
Evonik is also testing future demands to be met by light guide plates made from PLEXIGLAS® molding compounds. "We are currently testing new structures that are to improve light output," Baum explains. "More light is required from the backlight unit especially for the new 3D televisions, which are also to save even more energy, if possible."
Structure of a backlight unit for LCD displaysStructure of a backlight unit for LCD displays
Evonik Industries is a worldwide manufacturer of PMMA products sold under the PLEXIGLAS® trademark on the European, Asian, African and Australian continents and under the trademark ACRYLITE® in the Americas.
Evonik, the creative industrial group from Germany, is one of the world leaders
in specialty chemicals. Its activities focus on the key megatrends health, nutrition, resource efficiency and globalization. Profitable growth and a sustained increase in the value of the company form the heart of Evonik’s corporate strategy. Evonik benefits specifically from its innovative prowess and integrated technology platforms.
Evonik is active in over 100 countries around the world. In fiscal 2011 more than 33,000 employees generated sales of around €14.5 billion and an operating profit (EBITDA) of about €2.8 billion.
In so far as forecasts or expectations are expressed in this press release or where our statements concern the future, these forecasts, expectations or statements may involve known or unknown risks and uncertainties. Actual results or developments may vary, depending on changes in the operating environment. Neither Evonik Industries AG nor its group companies assume an obligation to update the forecasts, expectations or statements contained in this release.