LG companies applied for the most number of patents for organic light-emitting diode materials in South Korea, new data showed.

LG companies, including LG Display and LG Electronics, lodged a total of 939 patent filings for OLED materials in the 2015-2019 period, according to the Korean Intellectual Property Office on Thursday. Samsung Group and its affiliates came in second with 442 filings and Doosan companies ranked fourth with 203 patent applications.

Of the total 3,067 patent applications submitted in the same period, 79 percent of them were filed by domestic firms. Foreign companies accounted for 16.2 percent.

LG, Samsung and Doosan together accounted for 65.4 percent of 2,424 patent applications made by domestic firms.

“Though Korea is the greatest OLED manufacturer, it lacked source technologies for OLED materials compared to the US and Japan. Thanks to domestic firms’ extensive research and development, patent applications OLED materials, especially dopant, increased significantly,” said the KIPO official.

The patent application for dopants -- a key material that expresses the color of OLED panels -- has been led by domestic companies, which filed 110 dopant patent applications in the 2017-2019 period, five times greater than 22 cases filed by foreign companies. Of the total 132 cases, LG Chem accounted for 78 percent by filing 103 dopant patents.

By Kim Byung-wook (kbw@heraldcorp.com)