Back in 2009 LG-Display buys Kodaks OLED unit, now in 2012 LG-Display shows the world largest 55 inch OLED-Tv with Kodaks developed WOLED technology at the CES-2012. We give you more informations how this technology works.
One of the concerns for OLED technology has been the lifetime of the blue color, which has historically been less than red and green. Over time, this results in very dim blue pixels and shifting of the display toward yellow. With this new architectures to overcome this issue, in particular a very stable White OLED formulation, which can be used in combination with a color filter array to produce a full-color display. LGs White OLED architecture boasts a lifetime in excess of 100.000 hours. There are 8,766 hours in a year, so these devices are very stable. Another advantage of the White OLED approach is the elimination color shift over time due to one color dying out more quickly than the others.
Lg-Displays White OLED technology also meets or exceeds television standards for color gamut, image quality, brightness, contrast ratio and resolution.
The White OLED process, on the other hand, uses maskless technology, which is scalable to the glass sizes required to make television displays. An integrated color filter array is used, to produce full-color displays. LG uses an innovative design, RGBW, where a fourth unfiltered sub pixel is used to reduce the power consumption by ~50% in typical usage.
How works LG-Displays WOLED-TV technology in detail?
In this method, a four sub-pixel (RGBW) is utilized, with the color being provided by appropriately filtering the white emission. Compared to the conventional approach of pattering the individual RGB emitters, the white-based architecture offers advantages in manufacturability as well as higher levels of operational stability and color gamut. In particular, the white-RGBW (W-RGBW) architecture avoids the differential aging problem commonly encountered with the direct patterned emitter approach, which typically results from the more rapid degradation of the blue emitting sub-pixel (compared to the red and green. LGs W-RGBW approach does not suffer from this problem because Lgs white emitting structure is highly stable and the white spectrum does not shift in color during long term operation. Hence the color emitted by the OLED display remains constant over time. The benefits include scalability, no need for shadow mask, lower manufacturing cycle time and better production yield.
“Our objective has always been to actively define and lead emerging display technology markets,” said Dr. Sang Beom Han, CEO and Executive Vice President of LG Display. “Although OLED technology is seen as the future of TV display, the technology has been limited to smaller display sizes and by high costs, until now. LG Display’s 55-inch OLED TV panel has overcome these barriers.”