The method of depositing RGB emitting layers at each pixel is called the"Shadow Mask Patterning Method". Since the displays produced by this method have independent emitting layers, they have excellent color purity and contrast. Also, it is possible to have high luminance efficiency and low power consumption, because RGB color filters are not used.
The method which produces colors through the use of RGB color filters is called"Color Filter Method". With this method, the OLED materials, including RGB color elements produce white light which is then filtered to obtain the desired colors. It is not necessary to have a wide variety of OLED materials so only one kind of OLED material is used to produce white light. Some disadvantages are low color purity and contrast. Also, the filters used with this method absorb most of the light energy emitted, requiring the white light to be relatively strong. Therefore power consumption for the displays produced by this method is higher.
Both mono-color panels and full-color panels have these characteristics. Tohoku Pioneer will continue to develop OLED materials and panel designs focusing on the advancement of "Shadow Mask Patterning Method".