New OLED printing technology enables 500ppi OLED display
Sony unveiled a new printing technology for OLED displays in a technical paper at the SID 2012 display fair. With the offset printing technology, according to Sony, a pixel density of 500ppi can be achieved.
Based on Oled Info, Sony’s OLED offset printing technology uses the so-called slit coating method to deposit a coating of organic ink on a flat surface. Excess, organic ink is removed via a stamp, provided with the inverse pattern of the final sub-pixels. As a final step, the TFT substrate is aligned with the substrate and the OLED material is picked up by this substrate.
Both the red and green sub-pixels would be ‘printed’ in this way, while the blue OLED material would be applied via the usual vapor deposition method. In this way, Sony thinks that OLED screens with a pixel density of up to 500ppi are possible.
Sony already showed a 3″ OLED screen with VGA resolution, good for a pixel density of 270ppi, based on this technology at the SID 2011 fair, but did not disclose any details about the production method used at the time.