Teijin Limited

Bayer Aktiengesellschaft

Kansai University

Akihiko Uchiyama

Shunichi Matsumura

Yoshiro Tajitsu

Takashi Kushida

Yuhei Ono

Kaoru Iwata

Toshiaki Yatabe

Nobuaki Kido

Yoshinori Ikeda

Takeshi Sasaki

Tomoyoshi Yamamoto

Kiyonari Hashidzume

Satoshi Kitazawa

Michio Yamaura

Tatsuichiro Kon

Kazuo Yahata

Jyuhou Matsuo

Masakazu Tsujikura

Jyuho Matsuo

The present invention provides a retardation film which can remarkably improve the controllability of retardation, and can also sufficiently control the wavelength dependency of retardation. The retardation film of the present invention can achieve a widening of the viewing angle at a high degree, when it is applied to a liquid crystal display device. Further, the present invention provides a laminated polarizing which comprises the retardation film and enables widening the viewing angle. Furthermore, the present invention provides a liquid crystal display device having high performance, especially a widened viewing angle. The retardation film of the present invention comprises a structural body which simultaneously has form birefringence and molecular-orientation birefringence. Specifically, the retardation film comprises a periodic structure () having a unit of at least two layers () having different average refractive indices from each other, and at least one of the at least two layers is a layer having optical anisotropy due to molecular-orientation birefringence.

Retardation film, laminated polarizing film, and liquid crystal display device

A laminated polarizing film that is capable of enhancing a viewing angle of a liquid crystal display device, particularly in an IPS mode, is provided. The laminated polarizing film can be obtained by adhering a phase retardation film and a polarizing film by a roll-to-roll process. Specifically, the laminated polarizing film contains a negative substantially uniaxial optical film containing a thermoplastic polymer having a negative molecular polarizability anisotropy, a positive optical film containing a thermoplastic polymer having a positive molecular polarizability anisotropy, and a polarizing film, that are laminated at least in this order, a slow axis within a film plane of the negative substantially uniaxial optical film and a slow axis within a film plane of the positive optical film are substantially in parallel to each other, and each are substantially perpendicular to an absorption axis of the polarizing film, a positional relationship between a principal orientation direction of polymer main chains of the negative substantially uniaxial optical film and the absorption axis of the polarizing film is substantially in parallel, and a positional relationship between a principal orientation direction of polymer main chains of the positive optical film and the absorption axis of the polarizing film is substantially perpendicular.

Laminated polarizing film, phase retardation film, and liquid crystal display device

A retardation film comprised of a single oriented polymer film, characterized in that the retardation at wavelengths of 450 nm and 550 nm satisfies the following formulae (1) and/or (2), and the water absorption is no greater than 1%.R(450)/R(550)&#x3c;1 &#x2003;&#x2003;(1)K(450)/K(550)&#x3c;1 &#x2003;&#x2003;(2)where R(450) and R(550) represent the in-plane retardation of the oriented polymer film at wavelengths of 450 nm and 550 nm, respectively, and K(450) and K(550) are the values calculated by K=[n&#x2212;(n+n)/2]&#xd7;d (where n, nand nrepresent the three-dimensional refractive indexes of the oriented polymer film as the refractive indexes in the direction of the x-axis, y-axis and z-axis, respectively, and d represents the thickness of the film) for the oriented polymer film at a wavelength of 450 nm and 550 nm, respectively. There are provided laminated retardation films and liquid crystal display devices employing the retardation film.

Retardation film and optical device employing it

A uniaxially or biaxially oriented film which is made from a specific polycarbonate having a fluorene ring and a glass transition temperature of 165&#xb0; C. or higher and which has a heat shrinkage factor when it is heated at 90&#xb0; C. for 500 hours of 0.1% or less, and a ratio of retardation R(450) within the film plane at a wavelength of 450 nm to retardation R(550) within the film plane at a wavelength of 550 nm of 1 to 1.06. This film can be used in a high-quality liquid crystal display device such as a vertical alignment liquid crystal display device and is useful as a retardation film which almost solves a frame problem.

Polycarbonate-based oriented film and retardation film

The present invention provides a liquid crystal display device of VA mode having decreased leakage of light over a wide range and giving a clear and almost achromatic black display by using a retardation film A having smaller retardation with shorter wavelength in combination with a retardation film C having larger retardation with shorter wavelength. Accordingly, a high-quality liquid crystal display device having excellent picture quality can be produced by the present invention.

Liquid crystal display element, and use of phase difference film used the same for

A film which is a single polymer film and has a smaller phase difference as the wavelength becomes shorter. This film is made from an olefin-based polymer which has an alicyclic group in the side chain, such as hydrogenated polystyrene, the amount of the alicyclic group in the side chain being 60 to 90 wt % based on the whole polymer, and satisfies the following expression:(450)/(550)&#x3c;1wherein R(450) and R(550) are phase differences on the film plane at a wavelength of 450 nm and a wavelength of 550 nm, respectively.

Optical film

In the present invention, a retardation film is produced by adjusting the mixing ratio of at least two kinds of mutually compatible polymers A and B and by forming the resulting mixture into the film. The polymers A and B are copolymers comprising respective two common repeating units and different in copolymerization composition. According to the present invention, the retardation film having the desired wavelength dispersion can industrially and simply be produced. Furthermore, there can be provided the high-quality retardation film capable of controlling the wavelength dispersion of the retardation at a high level.

Process for producing retardation film

Phase difference film, phase difference film composite and liquid crystal display device using the same

Application of light source including light guide for emanating linearly polarized light to liquid crystal display with haze anisotropy

A film of the present invention is an oriented film having a light-scattering property varying with an incident angle and is useful e.g. as a viewing angle improvement film effective for improving the picture quality of a liquid crystal display device, especially for expanding the viewing angle. This oriented film is composed of a thermoplastic polymer and contains a number of micro voids participating in the above scattering property in the film. It can be produced by uniaxially drawing a film composed of a thermoplastic polymer under temperature and draw-ratio conditions to form grooves on the surface of the film perpendicular to the drawing direction.

Orientated film having pores

Growing community of inventors

Hino, Japan

Akihiko Uchiyama