A Low-Power Pixel Circuit Comprising Low-Temperature Poly-Silicon and Oxide TFTs for Liquid Crystal Displays with Panel Self-Refresh Technology

In this letter, we propose a new pixel circuit with low-temperature poly-silicon and oxide (LTPO) thin-film transistors (TFTs). The proposed pixel circuit can significantly reduce the power consumption of liquid crystal displays (LCDs) while maintaining their conventional features, by virtue of extremely low off-state current of n-type oxide TFTs and constant data voltages. Furthermore, p-type low-temperature poly-silicon (LTPS) TFTs can make the circuit simpler than when only n-type or p-type TFTs are used due to its complementary operation. By fabricating the circuit with the LTPO process, we successfully verify the circuit performance under continuous operation without further programming. Consequently, we believe that the proposed pixel circuit can provide low-power LCDs, even maintaining their conventional features.