Global Lighting Technologies (Taiwan) Inc exhibited an edge type LED backlight unit that can reduces the thickness of large LCD TVs at FPD International 2008, which took place from Oct 29 to 31, 2008.
The company exhibited a prototype of a light guide plate intended for use in 52-inch LCD TVs and demonstrated a 46-inch LCD panel. The LED light sources are only located at the bottom sides of the panels. This technology is expected to reduce the size and thickness of backlight units, the thickest components in LCD panels.
When LED light sources are gathered on one side of an LCD panel, electronic components that were previously located on the back of the panel can be relocated to the other three sides, reducing the thickness of the panel.
The patented light-guide-plate designs and technologies of Global Lighting Technologies realized the uniform and high luminance of the large 52-inch screen using light sources located only on a single side, according to the company. Though the details of the technologies were not revealed, the company mentioned microlens array technology.
The prototyped light guide panel for 52-inch LCD TVs is only 1.5mm thick and weighs 1.89kg. It was developed responding to a request by an LED manufacturer, the company said.
The 46-inch LCD panel has 126 LED light sources located at the bottom of the panel and is equipped with a 5mm-thick light guide panel. Its backlight unit features a luminance of 6000cd/m2 and weighs 8.6kg. The uniformity of the luminance is 85%. The color gamut is 100% NTSC standard. Global Lighting Technologies plans to commercialize this backlight unit in 2009.
It is important to develop measures to deal with heat because LEDs are spaced close together when gathered on one side of a panel; LEDs can not effectively illuminate the light guide plate if the light guide panel expands due to heat. The company did not disclose the heat prevention measures it adopted but said they were developed jointly with an LED manufacturer.
Global Lighting Technologies also exhibited a 46-inch LCD panel that has LED light sources installed on the top and bottom sides. The LCD panel has a total of 160 LED light sources, with 80 of them on each side. Its backlight unit weighs 12.2kg and has a luminance of 6,400cd/m2. The uniformity of the luminance is 85%. The color gamut is 100% NTSC standard. Commercialization is scheduled for 2009.
Global Lighting Technologies is a developer of light guide panels. The company sells LED backlight units incorporating its light guide panels to LCD panel manufacturers. In respect to components of backlight units other than light guide panels such as LEDs and radiator plates, general-purpose products are used, according to the company.
This time, the company exhibited its products at the booth of Midoriya Denki Co, the distributor for Global Lighting Technologies in Japan.