OPTICAL FILM, BACK LIGHT UNIT AND LIQUID CRYSTAL DISPLAYHAVING THE SAME

摘要

An optical film, a backlight unit and a liquid crystal display device having the same are provided to suitably adjust an angle between the first film and the second film, thereby preventing a moire phenomenon. The first film comprises a prism-shaped pattern on an upper surface of the first film. The second film comprises a cylinder shaped pattern in an upper surface of the second film and is positioned at a lower surface of the first film. A valley part(31) of the second film and a valley portion(41) of the first film are not parallel and are twisted. When the twist angle is 30 to 60 degrees, a moire phenomenon is remarkably improved without brightness decrease.