Which country invented the organic light-emitting diode screen?

Organic light emit diodes originate from electroluminescent organic material discovered in academic research. It is recognized that Deng Qingyun of Kodak Company invented the first organic light-emitting diode device and applied for a patent (1985), using small molecular organic materials. Later, Cambridge applied for the patent of organic light-emitting diode (about 1990) with polymer organic materials. These earliest basic patents have now expired.