Back in 2013, Fujifilm and imec jointly developed a new process to deposit and pattern OLED materials using existing i-line photolithography equipment. The two companies have now demonstrated a full-color photoresist OLED. They say that this could lead to a new process that can be used to produce high-resolution large-area OLED displays in a cost-effective way.
In the new prototype, the two companies patterned red, green and blue OLED materials to create a subpixel pitch of 20 micrometer. The full device is 40x40 pixels and achieved a density of 640 PPI. As you can see in the image above, UV rays were used to confirm the result.
This process can be adapted to created OLEDs with four basic colors (maybe similar to the recent RGBY OLED demonstrated by AUO) or OLEDs that have integrated photodetectors between the pixels (similar to Fraunhofer's bi-directional OLEDs).