Matsushita Electric Industrial Co., Ltd.

Tomoaki Sekime

Hisanori Yamaguchi

Yoshio Iwai

Tetsu Ogawa

Yoshihiro Sakurai

Naoki Kato

Deviation in phase difference of the light passing each of the red, green, and blue dots, i.e., 2&pgr;*(&agr;*d *&Dgr;n &plus;Re )/&lgr; , 2&pgr;*(&agr;*d *&Dgr;n &plus;Re )/&lgr; , and 2&pgr;*(&agr;*d *&Dgr;n &plus;Re )/&lgr; , are matched when thickness of a liquid crystal layer at red, green, and blue dots are d , d , and d ; wavelength of a visible light passing each dot is &lgr; , &lgr; , and &lgr; ; refractive index anisotropy of the liquid crystal layer in the visible light wavelengths &lgr; , &lgr; , and &lgr; is &Dgr;n , &Dgr;n , and &Dgr;n ; and retardations of a retardation plate are Re , Re , and Re . This enables the achievement of a reflective color LCD with high achromatic color during white display and high contrast display.

Retardation matching using the liquid crystal twist angle for different color dots within a pixel of a reflective color LCD

A reflection type liquid crystal display device having a wide viewing angle, and capable of assuring a light utilization factor at or above a certain value for bright display even when conditions of an external light are varied is provided. The reflection type liquid crystal display device comprises (a) a liquid crystal cell comprising an upper substrate, a lower substrate and a liquid crystal layer between the substrates, (b) a polarizing film provided in a side of the upper substrate in the liquid crystal cell, (c) light reflecting means provided in a side of the lower substrate in the liquid crystal cell; and (d) an optical member provided between the polarizing film and the liquid crystal cell, and having a retardation axis when it is viewed in the normal direction. An angle between an absorption axis of the polarizing film and the retardation axis of the optical member is within a range of about 88&deg; to about 92&deg; or about &minus;2&deg; to about &plus;2&deg; . A retardation value in relation to the normal direction of the optical member is within a range of about 50 nm to about 500 nm.

Reflection type liquid crystal display device

In a reflective liquid crystal display device with a single polarizing film and two retardation films located in between the polarizing film and liquid crystal cell, the angle of twist of nematic liquid crystal is 45&deg;&tilde;90&deg;, the product of the birefringence of the liquid crystal and the thickness of the liquid crystal layer is 0.20 &mgr;m&tilde;0.30 &mgr;m, the retardation value of the retardation film on the polarizing film side is 0.13 &mgr;m&tilde;0.18 &mgr;m, the retardation value of the retardation film on the liquid crystal cell side is 0.13 &mgr;m&tilde;0.18 &mgr;m, and the Z coefficient of each of two retardation films is 0.3&tilde;1.0. This invention is featured by the following optical relations, that is, &Oslash; 75&deg;&tilde;195&deg;, &Oslash; &minus;&Oslash; , 105&deg;&tilde;115&deg;, and &Oslash; &minus;&Oslash; , 165&deg;&tilde;175&deg;, where &Oslash; , &Oslash; and &Oslash; are angles formed by the reference line and respectively the direction of the absorption axis of the polarizing film, the direction of the slow axis of the retardation film on the polarizing film side, and the direction of the slow axis of the retardation film on the liquid crystal cell side. With the foregoing construction, a high contrast display of bright achromatic white and achromatic black is achieved.

Reflection liquid crystal display element

The reflective liquid crystal display device uses only one polarizing film but achieves display of bright white and achromatic color with high contrast. The twisting angle of a nematic liquid crystal is set to 45&deg; to 90&deg;, and the retardation value of a liquid crystal layer is set to &Dgr;nLC&middot;dLC&equals;0.20 &mgr;m to 0.30 &mgr;m. Two retardation films are configured with a structural component having small chromatic dispersion in refractive index anisotropy and a z coefficient from 03 to 1.0. Retardation values of these two retardation films are set to RF &equals;0.23 &mgr;m to 0.28 &mgr;m, and RF &equals;0.13 &mgr;m to 0.18 &mgr;m. When the angle of an absorption axis direction of the polarizing film is denoted by &phgr;P, and the angles of retardation axes directions of the two retardation films are denoted by &phgr;F and &phgr;F a set of Formulae &phgr;P&equals;75&deg;-195&deg;, &phgr;P-&phgr;F &equals;95&deg;-115&deg;, and &phgr;P-&phgr;F &equals;155&deg;-175&deg; are satisfied.

Reflective liquid crystal display device

A liquid crystal display device with excellent display characteristics such as dot defects and missing of pixels prevented from occurring, a bright display screen and the like can be realized. In addition, a yield rate is enhanced remarkably. The display device has a transparent substrate, non-linear elements, each having a plurality of electrodes, disposed on the transparent substrate, a protective film disposed on each respective nonlinear element of above, an interlayer insulating film disposed on the protective film and a pixel electrode disposed on the interlayer insulating film. An opening, the cross-section of which is configured in a V-letter like slanting shape, is formed in the protective film and interlayer insulating film, respectively. The opening is exposed to the surface of the nonlinear element. Each respective opening of above forms a first end part on the protective film and a second end part on the interlayer insulating film and the first end part is located outside of the second end part. One of the plurality of electrodes disposed on the nonlinear element is in contact with the pixel electrode in the opening.

Liquid crystal display device, and video display apparatus, information processing apparatus using it and method thereof

Reflection type liquid crystal display element

A reflective liquid crystal display device of the present invention has the following construction. Only one polarization film is needed. The twist angle of the nematic liquid crystal layer is set in the range of 0&deg; to 90&deg;. The product of the birefringence of the nematic liquid crystal layer &Dgr;n,and the thickness of the liquid crystal layer d,, &Dgr;n,&middot;d,, is in the range of 0.35 &mgr;m to 0.50 &mgr;m. The birefringence difference, &Dgr;R&equals;R,&minus;&Dgr;n,&middot;d,is in the range of &minus;0.20 &mgr;m to 0.00 &mgr;m. When a reflective liquid crystal display device is seen from a side of a substrate positioned at the upper side, the direction of the liquid crystal which is twisted to a side of a substrate positioned at the lower side is designated as the positive direction, &phgr;,represents an angle between the base line and the longer axis direction of the liquid crystal molecule which is positioned most closely to a first substrate, &phgr;,represents an angle between the base line and the retardation axis direction of the polymer film, &phgr;,represents an angle between the base line and the adsorption axis direction of the polarization film, &phgr;,&minus;&phgr;,is in the range of 70&deg; to 110&deg;and &phgr;,&minus;&phgr;,is in the range of &minus;90&deg; to &minus;60&deg;.

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Ishikawa, Japan

Tomoaki Sekime