Optical compensation film

A series of other examples are given in the literature. " The method of preparation of the optical compensation film has been described in detail... 

K. Tasaka, T. Yajima, N. Kuzuhara, and H. Umeda. Optical compensation film, viewing angle compensation integral type polarizing plate and liquid crystal display apparatus. US Patent 7105213, assigned to Konica Minolta Holdings, INC (Tokyo, JP), September 12, 2006. 

Also, the chemistry and polymerization of discotic monomers has been reviewed [10]. Their current and emerging uses are in optical compensation films for liquid crystal displays, carbon nanostructures, organic electronics, solar cells, light-emitting diodes, and field-effect transistors. 

FIGURE 3.5 (a) Natural orientation of a film of an No. (b) and (c) are controlled by the use of additives and surface treatment (above) along with a key to the molecular structure of the photopolymerizable No exploited in the Fuji optical compensation film. Examples of the types of materials used to control the orientation of the director at the air-liquid crystal and solid-liquid crystal interface (below). Reprinted with permission from Reference 14. Copyright 2002 Elsevier. 

SCHEME 3.3 Chemical structures of the revolutionary DLC compounds which have found real practical application in LCD devices as optical compensation films to enlarge the viewing angle and enhance the contrast ratio. 

To obtain a comparable viewing angle with VA and IPS, OCB requires more sophisticated optical compensation based on a discotic material [58]. Figure 8.31 shows the compensation schemes for a normally white OCB mode. The fundamental idea is similar to that for TN. The retardation matching between the cell and the optical compensation film is especially important for the OCB mode, partially because the black state of the normally white OCB cell has a finite residual retardation value that must be compensated by an optical film. For example, any retardation fluctuation of the cell or the film is easily noticeable. The OCB system requires a high level of uniformity. And the cell parameters, as well as the film parameters, should be optimized in order to maximize the optical performance. 

H. Mori, Y. Itoh, Y. Nishima, et al.. Performance of a novel optical compensation film based on negative birefringence of diseotie eompound for wide-view-angle twisted-nematic liquid crystal displays, Jpru J of Appl. Phys., 36, 143 (1997). 

The wide view film (WV film) was developed by FUJlblLM Co., Ltd. (see Fig. 4.5) and released in December 1995. It is an optical compensation film for liquid crystal displays (LCDs). LC display modes are classified into several categories, but the most widely used mode for note PCs, monitors, and cell phones was the TN (twisted nematic) LCD because of its low power consumption. 

Silver halide photosensitive materials for photographic purposes were the main products of FUJIFILM, and in the 1990s, future market projections did not hint any decline. Thus, silver hahde photosensitive materials were mainstream materials in our company. As a result, less than 1 % of researchers developed optical films for LCDs. Our team had developed and commercialized an optical compensation film for super twisted nematic (STN) LCDs since 1987, but we were greatly defeated by competitions that had products with better performance, but we were greatly defeated by competitors that had products with better performance. Thus, in 1992 we faced the closing down of our unit. 

H. Mori, M. Nagai, H. Nakayama, Y. Ito, K. Kamada, K. Arakawa, K. Kawata, Novel optical compensation method based upon a discotic optical compensation film for wide-viewing-angle LCDs, SID 03 Digest, 1058-1061(2003)... 

From these days, the optical simulation of complex optical compensation films for designing high-quality displays became essential [75]. In the similar way, the design of the electrode slits and protrusions used in the pixel division method in the vertical alignment (VA) mode has been carried out by continuum simulation [76]. 

There are as yet ho accepted standard materials for discotic nematic liquid crystals. It is expected that the birefringence of these materials will be negative, and they have already found application as optical compensation films for liquid crystal displays [23]. In order to illustrate an example of the optical properties of discotic nematic liquid crystals, we give in TABLE 10 measurements of the ordinary and extraordinary refractive indices of hexakis[(4-octylphenyl)ethinyl]benzene (Tm = 100 C). These are taken from [24] and were measured for a wavelength of 589 nm. 

US 6,582,775, J. A. Payne and J. W. Hoff, (Eastman Kodak Co.), Process for making an optical compensator film comprising photoaligned orientation layer, C09K 19/02 (427/508) (June 2003). 

US 6,822,713, O. Yaroshchuk, Y. Reznikov, J. R. Kelly, L. C. Chien, and T. Sergan, Optical compensation film for liquid crystal display, (Kent State University), G02B 5/128 (349/117) (November 2004). 

An optical compensation film for a liquid crystal display is provided wherein the film is a polymer that is capable of producing light induced anisotropy. The film is irradiated with light to form an optical axis or axes. 

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