Memory-in-Pixel Circuit for Low-Power Liquid Crystal Displays Comprising Oxide Thin-Film Transistors

Abstract

We propose a new memory-in-pixel (MIP) circuit with only oxide thin-film transistors (Ox-TFTs) for a low-power liquid crystal display with flicker-free feature. The proposed MIP circuit is composed of two new memory circuit units comprising two Ox-TFTs and a capacitor. The proposed memory circuit can modulate the threshold voltage via a simple driving scheme. When the threshold voltage is shifted properly, Ox-TFTs maintain the ON or OFF state by virtue of their extra low leakage current, which enables the MIP operation. By applying the black or white voltage to the pixel directly, flicker can be eliminated. We fabricated the MIP circuit and investigatedthe circuit performance depending on the capacitance and TFT sizes. Finally, we verified the feasibility of the proposed MIP circuit for low power operation.