Amorphous IGZO TFT-Based Pixel Buffer to Suppress Blue-Phase Liquid Crystal High-Frequency Effect

This letter discusses the frequency effect of polymer-stabilized blue-phase liquid crystal (BPLC) on the data voltages of a conventional pixel circuit and develops a new pixel buffer that exploits amorphous indium-gallium-zinc-oxidethin-film transistors (TFTs). During high-speed operations, BPLC seriously distorts data voltages because of the highly frequency-dependent-dielectric anisotropy. To lessen the frequency-dependent effect of BPLC, a source-follower structure is integrated into the proposed pixel buffer to prolong the charging time of the BPLC cell. The experimental results show that the source-follower yields linear output characteristics. Further compensation for TFT VTH shifts and suppressing the leakage current are confirmed to make the data voltages on the BPLC cell highly uniform and stable.