An object is to provide a phase difference compensation element capable of improving the contrast of a liquid crystal display device while solving the problems of a high cost, an increase in the lead time, an increase in the mounting space, and the durability. A phase difference compensation element includes: a phase difference imparting and reflection preventing layer; a first birefringence layer and a second birefringence layer in which an angle of a corner formed by a main axis of refractive index anisotropy and a surface of a transparent substrate is not 90 degrees; a third birefringence layer in which an angle of a corner formed by a main axis of refractive index anisotropy and the surface of the transparent substrate is 0 degrees, wherein, when segments acquired when the main axes of the first, second, and third birefringence layers are projected onto the transparent substrate are respectively denoted by a segment A, a segment B, and a segment C, relations of the following (1) and (2) are satisfied. (1) The angle of the corner formed by the segment A and the segment B is 45 degrees or more and 70 degrees or less. (2) The segment A and the segment C are approximately parallel with each other, or the segment B and the segment C are approximately parallel with each other.

A compensation film satisfies Inequalities 1 and 2, and an antireflective film and a display device are provided with the compensation film.

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A liquid crystal device includes a liquid crystal panel having a liquid crystal layer between an element substrate (first substrate) and a counter substrate (second substrate), and a translucent substrate disposed on a surface of the element substrate which is opposite to the counter substrate. An optical compensation layer which includes a first phase difference compensation element and a second phase difference compensation element formed of an oblique deposition film is integrally laminated on the substrate surface of the translucent substrate which is opposite to the liquid crystal panel. An alignment direction P of the liquid crystal molecules in plan view is a direction between an oblique deposition direction (first direction) of the first phase difference compensation element and an oblique deposition direction (second direction) of the second phase difference compensation element.

A viewing angle control device including at least one liquid crystal panel, at least one compensation film and polarizers is provided. Each of the at least one liquid crystal panel includes two transparent conductive layers and liquid crystal molecules. The polarizers include at least one first polarizer and a second polarizer. The at least one first polarizer is located between the at least one compensation film and the at least one liquid crystal panel. The second polarizer is located at a side of the at least one liquid crystal panel, the at least one compensation film and the at least one first polarizer. When there is no potential difference between the transparent conductive layers, an optical axis of each of the liquid crystal molecules is parallel or vertical to a transmission axis of the at least one first polarizer. A viewing angle controllable display apparatus is also provided.

Disclosed are an optical film, a method for preparing the same, and a liquid crystal display including the same. The optical film is a single film of a non-liquid crystalline thermoplastic resin, and includes: first and second surface part placed on both surfaces of the film in a thickness direction; and an inner part of the film placed between the first and second surface part, wherein the first and second surface part are not aligned with a tilt in the thickness direction, and the inner part of the film is aligned with a tilt in the thickness direction.

Disclosed is an optical compensation film including a supporter, and an optical compensation layer disposed on at least one surface of the supporter and including a polymer of cholesteric liquid crystal molecules having a structure in which a plurality of parallel-arranged liquid crystal molecules are helically arranged, wherein the cholesteric liquid crystal layer has a helical axis that is bent and tilted to the supporter at an angle represented by the following Equation 1; a method of manufacturing the same; and a liquid crystal device (LCD) including the optical compensation film.
H=(.sub.T.sub.B)*(d/d).sup.+.sub.B[Equation 1]
In Equation 1, H is a tilt angle of the helical axis of a layer of the cholesteric liquid crystal molecules; .sub.B is a tilt angle of liquid crystal molecule contact with the supporter; .sub.T is a tilt angle of a liquid crystal molecule disposed at a part of the layer furthest from the supporter; d is a thickness of the layer; d is a distance from the supporter along a vertical direction; is a degree of variation in tilt angle of helical axis; and 0.01.

A liquid crystal device includes a liquid crystal panel and an anti-dust translucent substrate fixed to a first surface of the liquid crystal panel. The translucent substrate includes a first phase difference compensation element having a first optical axis and integrally formed on a first surface of the translucent substrate, and a second phase difference compensation element having a second optical axis is opposed to the first phase difference compensation element. The second phase difference compensation element is placed such that an alignment direction of liquid crystal molecules of a liquid crystal layer is located in an angular position between the extending direction of the first optical axis and the extending direction of the second optical axis.

The present application provides a retardation element, having a first birefringent layer; and a second birefringent layer which has approximately the same average thickness as that of the first birefringent layer and contacts the first birefringent layer such that an angle formed between a first line segment representing the principal axis of refractive index anisotropy of the first birefringent layer and a second line segment representing the principal axis of refractive index anisotropy of the second birefringent layer is neither 0 nor 180 when the first line segment and the second line segment are projected on the transparent substrate such that an end A of the first line segment at a side of the transparent substrate and an end B of the second line segment at a side of the transparent substrate coincide with each other.

A transflective liquid crystal display device provided with a plurality of pixels, and includes: a first polarizer, a first phase difference layer, a first substrate, a liquid crystal layer, a second substrate, a second phase difference layer, and a second polarizer. The first substrate includes a reflective layer. The first phase difference layer includes a first /2 plate and a first /4 plate. The second phase difference layer includes a second /2 plate and a second /4 plate. At least one of the first phase difference layer and the second phase difference layer further includes a positive C plate. The liquid crystal layer takes a twist alignment when no voltage is applied. Each of the plurality of pixels includes a reflective region in which light is reflected by the reflective layer to perform display and a transmissive region in which light is transmitted to perform display.

A viewing angle control system includes sequentially: a first polarizer, a first optical compensation layer, a first TN-mode liquid crystal cell, a second polarizer, a second TN-mode liquid crystal cell, a second optical compensation layer, and a third polarizer. The first and second optical compensation layers each exhibit minimum retardation in a tilted direction rather than in a normal direction. The system provides high brightness in a front direction and low brightness in an oblique direction at a specific azimuthal angle when applied to a light source.