It’s reported that the light-emitting diode is only one existing technology that can be tapped to display images large enough for arena use and are viewable even in direct sunlight.  

Recently, Matsushita Electric Industrial Co. is installing its LED Astrovision technology in China. The Japanese consumer electronics giant will supply the Beijing Games with 25 LED Astrovision video display screens, delivering a total of almost 4,000 square feet. Each Astrovision screen consists of hundreds of LED units in one of two sizes--7.5 x 7.5 inches or 14 x 14 inches -- arranged in a grid. Assembling 1,296 LED units in a 16:9 widescreen format, for example, creates a display measuring 551 square feet. Up to 58,000 LED units can be installed per Astrovision screen.

One advantage of the LED, a self-emitting diode, is that it's easy to increase the brightness. Astrovision's luminance is as high as 5,000 candelas/ square meter; the brightest PDP can offer only 1,600 cd/m2. And the Astrovision panels are not flat, so slanting sunlight is deflected to the ground and away from the audience. That isn't possible with LCD or plasma flat panels.

LED displays have another advantage is that regardless of where they sit, a display installed in an arena must be able to deliver excellent images to the audience. Because an Astrovision screen consists of a number of LED units, each serving as light source, it can offer a horizontal viewing angle as wide as 150°. Further, there is hardly any color degradation in images on the screen, regardless of angle. A spectator viewing a 33 x 33-foot LED display can clearly see not just moving images, but also race results and athletes' names on the screen from as far away as 656 feet.

For displays smaller than 23 square feet, however, LCDs and PDPs remain far more effective. Because LED panels comprise discrete arrays of individually mounted RGB diodes, they're tough to miniaturize.