TDK Corp recently has released the structure of the see-through OLED panel which started mass production in March 2011.

The see-through OLED panel features a passive-matrix type and has a screen size of 2.4 inches. Its pixel count is 240 x 320 (QVGA). It can display color images. The brightness and transmittance of the new see-through OLED panel are 150cd/m2 and 40%, respectively.
 
TDK used metal electrodes as negative electrodes so that the company's proven manufacturing technologies can be used to start volume production as soon as possible. Then, to realize the transparency, it reduced the line width of negative electrodes so that only part of pixels are covered instead of covering the entire pixels. TDK calls this panel structure "thin-line electrode structure."

To commercialize the OLED panel, TDK combined white OLED and color filter for color display so that it is not necessary to use blue materials because of short life spans.

It has already been employed for Lenovo Corp's mobile phone that was released in March 2011. TDK exhibited a prototype of the see-through OLED panel at Ceatec Japan 2010. At present, TDK is producing the see-through OLED panel at TDK Micro Devices (Kitaibaraki City, Ibaraki Prefecture).