A Temperature Compensation Method by Adjusting Gamma Voltages for High Luminance Uniformity of Active Matrix Organic Light-Emitting Diode Displays

Abstract

In this paper, a temperature compensation method is proposed for active-matrix organic light-emitting diode (AMOLED) displays to achieve high luminance uniformity over a wide operating temperature range. The proposed temperature compensation method compensates for variation in OLED luminance according to temperature by adjusting the gamma voltages. To verify the proposed method, a built-in test circuit, which includes temperature sensors, current calculation block, current adjustment block, and gamma voltage generator, was fabricated using 90 nm complementary metal-oxide semiconductor process technology with 6 V high-voltage devices. The measurement results show that the proposed method achieves a high luminance uniformity with an OLED luminance variation of less than 1.54 cd/m2 over the temperature range of -45°C to 60°C. Therefore, the proposed temperature compensation method is suitable for AMOLED displays requiring high luminance uniformity.