Friday, April 20, 2007

Flat Light Emitting Diodes

Organic Light Emitting Diodes (OLEDs) are versatile, bright, efficient light sources. OLEDs are flat two dimensional lights made by placing a series of organic thin films between two conductors. When electrical current is applied, light is emitted. OLEDs are usually sandwiched between layers of protective clear plastic.

The General Electrics Ecomagination department has been developing OLEDs since 1999, and in 2003 they demonstrated a 2′x2′ OLED light source (see pictures above). For a behind-the-scenes look at what is going on, check out this recent blog post by one the GE engineers involved in OLED development. In the blog, there is a video that shows OLEDs being bent, spindled and mutilated.

OLEDs can be made very thin and very power efficient. While currently not as efficient as fluorescent lights, OLEDs have a very high theoretical maximum efficiency. Due to their efficiency OLEDs donĂ¢€™t produce waste heat and are thus a good source for illuminating things you donĂ¢€™t want to get hot, like cell phone screens.

The manufacturing process for OLEDs can include printing dots of different organic compounds on a clear plastic carrier to create a matrix of pixels that emit different colored light. These systems can be used in television screens, computer displays, and cell phone screens.

At the Las Vegas CES 2007 Summit Sony showcased 11 inch (resolution 1,024 x 600) and 27 inch (full HD resolution at 1920 x 1080) OLED televisions claiming a million-to-one contrast ratio and total thickness of 5 mm. According to news reports, Sony plans to begin releasing TVs this year.

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