Wang-Yang Li

Wide-View and Broadband Circular Polarizers for Transflective Liquid Crystal Displays

A simple wide-view and broadband circular polarizer comprising of a linear polarizer and two uniaxial films is proposed to enhance the viewing angle of transflective liquid crystal displays (LCDs). For the transmissive mode, over the entire 90deg viewing cone, the normalized light leakage from two stacked circular polarizers is suppressed to below 1.5times10-2, and contrast ratio over 10:1 is obtained using a normally black vertically aligned transflective LCD. At the same time, this configuration warrants a broadband operation and reasonably good viewing angle (10:1 contrast ratio is over 40 at all directions) for the reflective mode. The physical mechanisms for achieving broadband operation and wide viewing angle are discussed.

Extraordinarily wide-view circular polarizers for liquid crystal displays

A new broadband wide-view circular polarizer is proposed for high transmittance multi-domain vertical-alignment liquid crystal displays (MVA LCDs). This configuration only requires one biaxial plate in the conventional circular polarizer. The optimal film parameters are obtained analytically through spherical trigonometric method on the Poincaré sphere and through computer-aided parameter search method. According to this design, the high transmittance MVA LCD exhibits a contrast ratio CR 200:1 over approximately 80 degrees viewing cone.

P-152: High Performance Reflective and Transflective Displays Using Guest-Host Liquid Crystal Gels

Two high performance reflective guest-host liquid crystal displays (GH LCDs) using a dual-frequency liquid crystal (DFLC) gel and a negative liquid crystal (NLC) gel are developed. These polarizer-free GH-LCDs exhibit ∼50% reflectance, ∼200:1 contrast ratio, and <5 ms response time. Such reflective LCDs can also be used in double cell gap transflective displays.

Switchable transmissive and reflective liquid-crystal display using a multi-domain vertical alignment

— A wide-view transflective liquid-crystal display (LCD) capable of switching between transmissive and reflective modes in response to different ambient-light conditions is proposed. This transflective LCD adopts a single-cell-gap multi-domain vertical-alignment (MVA) cell that exhibits high contrast ratio, wide-viewing angle, and good light transmittance (T) and reflectance (R). Under proper cell optimization, a good match between the VT and VR curves can also be obtained for single-gamma-curve driving.

29.2: Switchable Transmissive and Reflective LCD for Mobile Displays

A wide-view switchable transmissive and reflective (STAR) liquid crystal display (LCD) in response to different ambient light conditions is proposed. This STAR LCD adopts a single cell gap multi-domain vertical alignment (MVA) cell that exhibits high transmittance (T) and high reflectance (R), and a good match between the VT and VR curves.

35.1: Single Cell-Gap Transflective FFS LCD Using Wire Grid Polarizer

A single cell gap and wide-view transflective LCD using fringe field switching LC cell and an internal wire grid polarizer as reflector is demonstrated. This transflective LCD exhibits a high light transmittance (T) and reflectance (R), and good match between the VT and VR curves.

P‐101: New Polarization Converter for Enhancing LCD Brightness

A novel polarization converter using reflective metallic gratings is developed. This device converts an unpolarized light to linear polarization with over 85% efficiency. Its application for enhancing the brightness of direct-view liquid crystal displays is emphasized.

P‐194: New 8‐Domain MVA LCD with Reduced Color Shift

A new MVA LCD is proposed by introducing an electric shielding layer to divide a unit pixel into at least two different regions with different threshold voltages. Such a MVA exhibits a wide view angle and much weaker color shift using only one TFT which is attractive for TV applications.

Circular polarizers using alternating positive and negative birefringence A films

In this paper, we have proposed a new design of wide-view and broadband circular polarizers for transflective LCDs, especially using a normally black VA mode. This design uses both positive and negative A-plates in the CP structure to self-compensate the off-axis phase. We believe this design will have a great impact on enhancing viewing angle of transflective LCDs.