An optimized blue-phase liquid crystal (BPLC) with a moderate dielectric constant, manageable capacitor charging time, high voltage holding ratio, and submillisecond gray-to-gray response time at room temperature is developed. Using protruded triangular IPS electrodes, the operation voltage can be reduced to 15V while keeping ~74% transmittance. Such a BPLC enables single-TFT addressing and 240-Hz operation. Potential application for color-sequential displays is emphasized. Our new approaches have solved the most critical charging time issue and would accelerate the emergence of the long-awaited blue-phase LCDs. The primetime for BPLCD is around the corner.

Color-converted micro-LED displays consist of a mono-color micro-LED array and color conversion materials to achieve full color, while relieving the burden of epitaxial growth of three-color micro-LEDs. However, it usually suffers from low efficiency and color crosstalk due to the limited optical density of color conversion materials. With funnel-tube array, the optical efficiency of the color-converted micro-LED display can be improved by ~3X, while the crosstalk is eliminated. After optimization of the tapper angle, the ambient contrast ratio is also improved due to higher light intensity.

A macroscopic model is developed for analyzing the electro-optics of short-pitch uniform lying helix (ULH) cholesteric liquid crystals (CLCs). Both flexoelectric effect and dielectric effect make important contributions to the maximum transmittance and operation voltage of the ULH devices. Based on the proposed macroscopic approximation, we derive an analytical expression to quantitatively evaluate the relative strength of these two effects. Very good agreement between theory and experiment is achieved. We also investigate the viewing angle of ULH CLC displays and find that their viewing angle characteristics are similar to those of conventional in-plane switching liquid crystal displays.

FIG. 5. The multi-domain multi-layer TN cell structure used in the simulation. Upper part: top view, and lower part: cross-section view. FIG. 6. Polarization state change of the light passing through a multidomain multi-layer TN cell: black dotted lines show the incident polarization state. Blue solid line shows the simulated outgoing polarization state.

A full‐color micro‐LED display can be achieved by red, green, and blue (RGB) chips or by a blue/ultraviolet (UV) micro‐LED array to pump downconverters. The latter helps relieve the burden of epitaxial growth of tri‐color micro‐LED chips. However, such a color‐converted micro‐LED system usually suffers from color crosstalk and low efficiency due to limited optical density of color converters. With funnel‐tube array and reflective coating on its inner surface, the crosstalk is eliminated, and the optical efficiency can be improved by more than two times. In addition, the ambient contrast ratio is also improved because of higher light intensity. The color gamut of this device is approximately 92% of DCI‐P3 standard.