| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a prism sheet, back light unit and liquid crystal display device which does not cause the irregularity of brightness and hardly causes the white spot phenomenon. <P>SOLUTION: This prism sheet can be obtained by covering the flat surface of a transparent base material film where unit prism or unit lens is formed on one side surface thereof and the other side surface is flattened with a layer consisting of light-transmissive material having tensile elastic modulus of 0.5-2500 MPa or a layer consisting of polyurethane. This back light unit is obtained by arranging the prism sheet in front of a light transmission plate in such a manner that the covering layer is made the light transmission plate side. This liquid crystal display device is constituted in such a manner that the liquid crystal display panel is illuminated by the back light unit. <P>COPYRIGHT: (C)2003,JPO |
