Almost all LCD HDTVs use fluorescent lights behind the the LCD panel to provide a backlight. This is a relatively inexpensive solution, but has a number of shortcomings, not the least of which is the reliance on mercury that is an environmental hazard, which in turn makes it difficult to dispose of and recycle the television at the end of its life.
As a result, many companies are looking at LEDs as a light source. They tend to be a bit more expensive, but depending on the configuration, they can offer some advantages. The newly announced Sony 55″ KDL-55XBR8 and 46″ KDL-46XBR8 models have a feature that Sony calls “TRILUMINOS“. This relies on a matrix of LEDs — clusters of red, green, and blue — to create a backlight that can be dimmed in specific regions of the panel This results in a lower light level for dark regions of an image, and the viewer sees an image with improved contrast. These 1080p sets also have 120 Hz refresh rate to minimize LCD motion blur, and support the Digital Media Extender link that allows users to add features such as Sony’s Internet Video Link that now provides access to YouTube video clips as well as other Internet video sources.