Ultra-High-Image-Density, Large-Size Organic Light-Emitting Device Panels Based on Highly Reliable Gate Driver Circuits Integrated by Using InGaZnO Thin-Film Transistors

Abstract

Large-size, organic light-emitting device (OLED) panels based on highly reliable gate driver circuits integrated using InGaZnO thin-film transistors (TFTs) were fabricated to achieve ultra-high image density (UHD). These large-size OLED panels were driven by using a novel gate driver circuit not only for displaying images but also for sensing TFT characteristics for external compensation. Regardless of the negative threshold voltage of the TFTs, the proposed gate driver circuit in OLED panels functioned precisely, resulting from a decrease in the leakage current. The falling time of the circuit is approximately 1.6 μs, which is fast enough to drive UHD OLED displays at 120 Hz. 120 Hz is most commonly used as the operating voltage because images consisting of 12 frames per second can be quickly shown on the display panel without any image sticking. The reliability tests showed that the lifetime of the proposed integrated gate driver is at least 1 × 105 h.