1. School of Electrical Engineering Kookmin University Seoul 02707 Korea
2. School of Electrical and Electronics Engineering Chung‐Ang University Seoul 06974 Korea
3. Circadian ICT Research Center Kookmin University Seoul 02707 Korea
4. Korea Research Institute of Standards and Science Daejeon 34113 Korea
5. Department of Electrical and Electronic Engineering Hanyang University Ansan 15588 Korea
6. R&D Center LG Display Company Paju 10845 Korea
7. OLED TV Business Unit LG Display Company Paju 10845 Korea