Contents

Abstructs of Reviews

Liquid Crystal DisplDevelopment of Optical Films for LCDs

Motohiro YAMAHARA and Kohji HIGASHI

Various optical films for LCDs have been developed for improving viewing angle dependences by changing contrast ratio and color shifts.In this paper,the development and trends of the polarizer,the compensation films and the surface treatment of polarizers are discussed.
Keywords :LCD, Polarizer, Compensation film, Surface treatment wide viewing angle, AG-coating, ARcoating

Birefringence Dispersion Control of Retardation Films for LCDs

Akihiko UCHIYAMA

A retardation film, which is an optical device to control polarized light by the anisotropy of the refractive index, is essential for a display device, particularly to obtain a high performance liquid crystal display (LCD).The birefringence dispersion of retardation films is important because it greatly affects the design and the performance of the LCDs.Conventionally,birefringence dispersion of the films was controlled by a combination of plural retardation films. Therefore, increasing the number of retardation films is inevitable in order to get a high performance LCD. We established a the theory for birefringence dispersion control of retardation films using novel molecular design.Control and wide banding for birefringence was realized by using a molecular designed polymer with positive and negative segment units.We also clarified that this theory can be applied to high performance LCDs with a simple device structure.
Keywords :Retardation film, LCD, Birefringence, Wavelength dispersion, Polymer

Development of Surface Films for LCD

Norinaga NAKAMURA

Despite remarkable progress in LCDs regarding surface films, which greatly affect the visibility of LCDs, evaluation methods of their characteristics have not yet been established.
We have correlated the characteristics of surface films to the visibility of LCDs, and have determined evaluation methods for such surface films.
Furthermore, we have also contributed to the enhancement of the visibility by supplying novel surface films with their advanced characteristics and techniques.
In this paper, we introduce evaluation techniques for the characteristics of surface films and developed novel surface films for LCD-TVs.
Keywords : Surface film,Anti glare,Internal diffusion, Low reflection, Anti static

Material Design of Plastic Retardation Films

Sadao FUJII

Plastic retardation film, such as expanded polycarbonate film is widely used for optical compensation of various LCD’s, and a number of optical characteristics are expected according to the different LCD modes. Adjustment of the birefringence caused by molecular orientation, the photoelastic birefringence, the wavelength dispersion of retardation, and the three-dimensional refractive index of the birefringence are important factors because they control the requirements for the plastic material that is used for the retardation film. The relationship between molecular configuration and these optical characteristics is considered, and the idea of the material design of the retardation film is shown.
Keywords : Retardation film, Molecular orientation, Photoelastic birefringence, Wavelength dispersion, Three-dimensional refractive index, Material design

Development Trend of Liquid Crystalline Optical Films

Suzushi NISHIMURA

In the liquid crystal display (LCD) not only liquid crystal (LC)cells containing low molecular weight liquid crystals are used but also optical films composed of LC materials.Recently,retardation film,wave plates,viewing angle compensators, temperature compensating retardation film, optical rotators and polarizers have been developed from LC materials. LC materials with unique advantages such as high birefringence and highorder structure formed by self-assembly in various LC phases can be applied to these optical films.
In this report,these liquid crystalline optical films are described for the first time.
Keywords : Liquid crystalline film,Optical film,Retardation film, Self assembly, High-order structure

Application of ZeonorFilm (R) used in Retardation Film

Takashi SATOH, Kouhei ARAKAWA and Masahiro YAMAZAKI

Liquid Crystal Display (LCD) technology has grown rapidly in recent years. This development depends on the technical innovation of the retardation films and of the LCD modes. This paper reports the advantageous properties of ZeonorFilm (R) used in retardation films and in protection films of a polarizing plate. We also show innovative production techniques,for example,the melt extruding method, wide film production, and the roll-to-roll method.