Nontwist quarter-wave liquid-crystal cell for a high-contrast reflective display

Abstract

We propose an optical configuration of a nontwist quarter-wave liquid-crystal cell for a high-contrast reflective display that can be applied to most nontwist display modes. By fabricating a homogeneous cell with the proposed configuration, we have demonstrated a high contrast ratio of 50:1 without using a wideband retardation film.

Light Leakage of Multidomain Vertical Alignment LCDs Using a Colorimetric Model in the Dark State

“…It is a rapid way of evaluating optical performance of color filters when developing new color resists. The colorimetric and photometric performance ( , , ) can be found (Figure 4) by considering the transmittance of the TFT, bump, and LC using (5) and (6). Without addressing the ratio of the bump area over a pixel area in this model, light leakage in the bump region is three times larger than nobump region.…”

“…However, the light leakages in the dark state and color shift at an inclined angle have not yet been improved. Therefore, enhancing the contrast ratio and eliminating the light leakage in the dark state are important goals [6,7]. Many conditions result in the light leakage such as light scattering from liquid crystals and the color filter, misalignment of crossed polarizers, and retardation of phase from liquid crystals [8,9].…”

Electro-Optical Characteristic of Two Domain Normally Black Electrically Controlled Birefringence Mode with Patterned Electrode Structure

“…LCD modes are classified by the primary LC alignment and electrode structure which affect the direction of electric field in a pixel as vertical alignment (VA) type nematic mode [1], in-plane switching (IPS) mode [2,3], twisted nematic mode (TN) [4,5,6], etc [7][8][9][10][11][12][13]. Among the several proposed LCD modes, TN electro-optical mode has many advantages [14,15] such as simple manufacturing process and high light efficiency.…”

Optical Design of a Normally-Black Twisted-Nematic Liquid Crystal Mode with Achromatic Dark State

“…For comparison, a wide-band HWP configuration consisting of two HWPs with OA of 22.5 and 67.5 , and a wide-band QWP configuration consisting of three HWPs with OA of 15 , 75 , and 15 are considered, between the parallel polarizers with TA of 0[8]. In a case of À45 and 145 nm, especially, the compensated NB-TN mode shows the dispersion characteristics superior to the conventional NB-TN mode and other optical film combinations, in the visible wavelength from 450 to 700 nm.…”