A Pixel Structure and a Simultaneous Driving Method for High Transmittance of Transparent Digital Information Displays

Abstract

This paper presents a transparent digital information display (DID) using a field sequential liquid crystal display (FS-LCD). The pixel structure and simultaneous driving method for FS-LCD are proposed to improve the transmittance of a transparent DID and to reduce color mixing artifacts. The proposed pixel consists of a memory stage and a liquid crystal (LC) driving stage, and all pixels are simultaneously operated together as the programmed data in the memory stage is simultaneously transferred to the LC driving stage. In addition, the data voltage boosting method with memory capacitor is adopted to maintain the transmittance of FS-LCD. The measured transmittance, contrast ratio, and color gamut are 16.7%, 4000, and 85.6% compared to NTSC in the CIE-1931 color space, respectively. The measurement results of the proposed transparent DID show higher transmittance and wider color gamut compared to conventional DIDs. Furthermore, to verify the reduction in the color mixing artifact, the color variations (Delta x and Delta y) in the x-axis and y-axis of the CIE-1931 chromaticity diagram are measured. The Delta x and Delta y are smaller than 0.002 across the whole display panel. Therefore, the proposed transparent DID shows superior color uniformity by reducing color mixing artifacts.