Previously, the largest OLED screen size was 77 inches, and it was a miserable 4K. While this combination is currently offered to consumers by the likes of LG Electronics, Sony and Panasonic, they all source their large OLED panels from LG Display.
LG is keeping quiet about the panel, and it does not seem the sort of product where you have to consider the price.
LG's main rival, Samsung Display has long shifted its focus from OLED TVs to QLED TVs. LG Display is now the sole large-size OLED display maker in the world. The outfit has spent a fortune to ensure that it continues to have the upper hand by ramping up OLED production capacity. It has also been sliding itself into mobile OLED panels which is controlled by Samsung.
Part of this includes the construction of a new OLED plant outside of Korea for the first time - in China's Guangzhou city, no less, and this was recently approved by the South Korean government. It seems that the big screen is just LG showing off.