Generalized mixed-mode reflective LCDs with large cell gaps and high contrast ratios

Abstract— A generalized mixed twisted-nematic/birefringent-effect mode reflective LCD is presented. This new mode encompasses all previously published reflective nematic LCD modes and is clearly shown on the parameter space diagrams. We also discuss how to obtain operating conditions of this generalized mixed-mode display with large cell gaps, low color dispersion, and high contrast at low voltages. This operating mode is particularly suitable for reflective crystalline-silicon-backplane active-matrix LCDs.     

Demonstration of the waveguide-based LCD

Abstract— We demonstrate a waveguide-based liquid-crystal display. Instead of using polarizers to control light intensity, high optical efficiency is obtained by using a liquid crystal to switch light out of a waveguide. Wide viewing angle is obtained by using a scattering screen.     

Microcrystalline‐silicon thin films by physical vapor deposition for wide‐area low‐temperature polysilicon production

A sputtered microcrystalline‐silicon thin film deposited on unannealed Corning Code 1737 glass has been shown to transform to polycrystalline material after excimer‐laser annealing at low energy densities, and below the full‐melt threshold. The homogeneous large‐grain polysilicon films obtained show promise for high‐yield manufacturing of large‐area LTPS displays. The material properties of the films will be presented and the properties of devices fabricated in the films will be discussed.     

Numerical approach to the physical behavior of fluorinated nematic liquid crystals

Abstract— A numerical approach to the physical behavior of fluorinated liquid crystals has been investigated. The molecular parameters, such as dipole moment and polarizability were calculated using a semiempirical molecular orbital (MO) method. Using these molecular parameters and the Maier-Meier theory, the temperature dependence of the dielectric anisotropy divided by the order parameter (Δ?/S) has been estimated. In addition, taking the temperature dependence of the order parameter S into account, the temperature dependence of the dielectric anisotropy Δ? has been estimated. The calculated results are in good agreement with experimental results.     

展宽LCD视角的新原理

扭曲向列型（ＴＮ）和超扭曲向列型（ＳＴＮ）ＬＣＤ，包括有源和无源矩阵，都有一个共同的缺点，即视角狭窄；审液晶材料的电光特性所造成的。现已开发出一种展宽ＬＣＤ视角的新方法，这一ＬＣＤ新的工作原理在解决其视角狭窄的问题时，对于ＬＣＤ显示器件而言，不是从其内部着手而是从其外部着手，本文将描述这种新型设计的各关键元件的工作原理。     

多晶硅有源矩阵液晶显示器

本文首先就用来制造有源矩阵液晶显示器的非晶硅和多晶硅材料作了性能比较,然后描述了多晶硅薄膜晶体管阵列的制造方法,以及在制造方法上取得的进展。     

Automatic defect inspection for LCDs using singular value decomposition

Thin film transistor liquid crystal displays (TFT-LCDs) have become increasingly popular and dominant as display devices. Surface defects on TFT panels not only cause visual failure, but result in electrical failure and loss of LCD operational functionally. In this paper, we propose a global approach for automatic visual inspection of micro defects on TFT panel surfaces. Since the geometrical structure of a TFT panel surface involves repetitive horizontal and vertical elements, it can be classified as a structural texture in the image. The proposed method does not rely on local features of textures. It is based on a global image reconstruction scheme using the singular value decomposition (SVD). Taking the image as a matrix of pixels, the singular values on the decomposed diagonal matrix represent different degrees of detail in the textured image. By selecting the proper singular values that represent the background texture of the surface and reconstructing the matrix without the selected singular values, we can eliminate periodical, repetitive patterns of the textured image, and preserve the anomalies in the restored image. In the experiments, we have evaluated a variety of micro defects including pinholes, scratches, particles and fingerprints on TFT panel surfaces, and the result reveals that the proposed method is effective for LCD defect inspections.     

Bit‐depth extension: Overcoming LCD‐driver limitations by using models of the equivalent input noise of the visual system

Abstract— Continuous tone, or “contone,” imagery usually has 24 bits/pixel as a minimum, with 8 bits each for the three primaries in typical displays. However, lower‐cost displays constrain this number because of various system limitations. Conversely, higher‐quality displays seek to achieve 9–10 bits/pixel/color, though there may be system bottlenecks limited to 8. The two main artifacts from reduced bit‐depth are contouring and loss of amplitude detail; these can be prevented by dithering the image prior to these bit‐depth losses. Our technique builds on Roberts's noise‐modulation idea and the subsequently influenced work in halftoning for hardcopy and dithering for displays. However, most halftoning/dithering work was primarily directed to displays at the lower end of bits/pixel (e.g., 1 bit as in halftoning) and higher ppi. We approach the problem from the higher end of bits/pixel/color, for example, 6–8, and lower spatial resolution (<100 ppi), which changes the game substantially from halftoning experience. Instead of spatial dither, it is better to use an amplitude dither. In addition, dynamic displays allow for the use of a temporal dithering component. This paper will report on techniques and observations made in achieving contone quality on ～100‐or‐less‐ppi LCDs starting from 4‐ to 8‐bit driver limits, and resulting with no visible dither patterns, noise, contours, or loss of amplitude detail at viewing distances as close as the near focus limit (～120 mm).     

Recent studies on multiplex driving of BTN‐LCDs

The main parameters of driving waveforms for BTN‐LCDs were investigated, and the effects on the display operation and dependence on temperature were measured. Based on experimental results, we have determined the most useful driving waveforms for practical operation, and also proposed a new driving method.     

High-performance reflective STN-LCD with a blazed reflector

Abstract— A reflective super-twisted-nematic liquid-crystal display (STN-LCD) using a blazed reflector is proposed. Application of the blazed reflector improves luminance and contrast ratio in reflective LCDs by directing the reflected image toward the observer and also by misaligning it from the direction of the surface reflection. The reflector needs proper scattering to eliminate casting a background by a specular image. Therefore, we studied two methods: one which makes the surface of the reflector uneven and the other which applies light-scattering material between the display and the reflector. Key features include almost a doubling in brightness and contrast ratio using the blazed reflector with the light-scattering material. Moreover, good white representation is obtained to optimize the refractive index in the normal direction of the retardation film.