A design method for flicker-free liquid crystal display panels based on indium-gallium-zinc-oxide thin-film transistors

Abstract

This paper proposes a design method to reduce the flicker of liquid crystal display panels based on indium-gallium-zinc-oxide (IGZO) thin-film transistors (TFTs). The proposed design method employs a human factor model to convert the flicker measured at low frame frequency (F-FRAME) to a modification value of the measured flicker (MVMF) having a frequency sensitivity of flicker, which can distinguish between no blinking and weak blinking. To investigate the causes and characteristics of flicker, the frequency component and increase factor of flicker are analyzed using the checkerboard and solid images. The increase factor in flicker is examined using IGZO TFTs with different antenna ratios (ARs) that cause the variation in threshold voltage of IGZO TFT. To verify the proposed design method, two test panels are implemented with asymmetric and symmetric ARs. The MVMFs of the 15 Hz component at a low F-FRAME of 30 Hz show that the solid image with a symmetric AR has an MVMF of -62.9 dB, which is improved by 24.3 dB compared to that with an asymmetric AR. Therefore, the proposed method is applicable for a flicker-free liquid crystal display panels at a low F-FRAME.