P‐13.20: Display quantity Improvement research of Trans‐Reflection display as Normal Black Mode

This paper investigates the inherent limitations of the ECB (Electrically Controlled Birefringence) Normal Black mode through optical simulations (Polar sphere analysis and optical simulation suite). It reveals that variations in the liquid crystal cell thickness (d) cause fluctuations in phase retardation (Retardation = △n • d), leading to abnormal black‐state luminance and chromaticity in both reflective and transmissive scenarios, thereby resulting in observable Gap Mura to the human eye. To overcome these limitations, a novel transflective display solution based on the Vertical Alignment (VA) Normal Black mode is proposed. This mode leverages the vertical alignment of negative dielectric anisotropy liquid crystals in the electric field‐off (OFF) state to eliminate phase retardation dependency, achieving a stable black state through orthogonal polarizers (POL). When the electric field is turned on (ON), the tilting of liquid crystals generates phase retardation, enabling the transition to the bright state. Experimental results demonstrate that the VA NB mode significantly outperforms the ECB NB mode in terms of black‐state uniformity, Mura suppression, and color performance. Although the VA NB mode requires the use of HWP (Half‐Wave Plate) + QWP (Quarter‐Wave Plate) dual‐layer compensation films, leading to increased costs, the RWD‐QWP (Reverse Wavelength Dispersion QWP) structure optimization can balance cost and optical performance. This study provides a superior solution for outdoor low‐power displays, validating the advantages of the VA mode in the field of transflective normally black displays, and offers significant reference value for advancing green display technologies.