LG Display Takes Sole Ownership of 9 US OLED Patents From LT Materials

LG Display has converted nine US patents on organic light-emitting diode (OLED) materials from joint ownership with supplier LT Materials to sole ownership, according to industry sources.

The nine patents were filed between 2019 and 2024. Two are registered and seven are still pending. In documents submitted to the US Patent and Trademark Office, the two companies stated that all rights had been assigned. One industry source said the patents mainly cover green host, hole blocking layer (HBL) and charge generation layer (CGL) technologies.

Korean patents are next

The two firms also co-filed 23 patents in South Korea, mostly on OLED materials and some on LED technology. On the 19th of last month they submitted a change-of-information correction notice for those patents, which is presumed to be a step toward transferring them to LG Display alone.

An industry source said LT Materials handed over its stakes after discontinuing part of its business, and that holding patents it no longer commercializes means paying annual fees for no benefit. According to market researcher UBI Research, LT Materials has supplied LG Display with green host, green prime and capping layer (CPL) materials for small and mid-size OLEDs, plus CPL, n-CGL and hole injection layer (HIL) materials for large white OLEDs.

A possible tie to Material Science

Another source suggested LG Display may want to nurture a different supplier, Material Science. That company began a government-backed project in July to develop CGL materials for tandem OLEDs, with the aim of supplying LG Display. Tandem OLEDs stack two or more emitting layers, which can raise brightness and improve power efficiency and device lifetime compared with single-stack designs.

Material Science says it wants to localize n-CGL and p-CGL materials and replace those from Japan's Toray (n-CGL) and Germany's Merck (p-CGL), which held dominant positions for more than a decade. Both also supply OLED materials to LG Display. LG Display is the third-largest shareholder in Material Science with a 7.9% stake, and one source said it would likely want to exit after the company lists.

The link to Material Science is the interpretation of industry sources, not a confirmed motive. Neither company has publicly explained the patent transfer.