LG Display said it would invest 3 trillion won or $2.6 billion in its organic light-emitting diode (OLED) panels production line in South Korea.
The Apple iPhone supplier earlier forecast a tough 2019 as it invests heavily in OLED panels at a time of weak demand for smartphones and tech gadgets in general.
The display screen maker said in a statement it would continue to expand its lead in the OLED TV market.
LG Display is shifting its mainstay liquid crystal display (LCD) business toward next-generation OLED panels, as the LCD panel industry is crowded with Chinese rivals.
The South Korean firm is scheduled to report its second-quarter earnings later Tuesday.