| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a variable viewing field angle type liquid crystal display device whose cost is reducible. <P>SOLUTION: A surface light source is arranged that comprises a phase difference element 18 having a phase difference layer 18a which is arranged on a projection side of a light source part 8 and has a plurality of first phase difference parts 19 and second phase difference parts 20 arrayed alternately and the other phase difference layer 18b which is arranged while spaced from the phase difference layer 18a and also has third phase difference parts 21 arrayed corresponding to the first phase difference parts 19 and fourth phase difference parts 22 arrayed corresponding to the second phase difference parts 20. Here, the phase difference element is characterized by setting the total phase difference between the first and third phase difference parts 19 and 21 to linear polarized light (a) projected from the light source part 8 and the total phase difference between the second and fourth phase difference parts 20 and 22 to a value for rotating the plane of polarization of linear polarized light (a) by 90° and setting the total phase difference between the first and fourth phase difference parts 19 and 22 to the linear polarized light (a) and the total phase difference between the second and third phase difference parts 20 and 21 to a value for rotating the plane of polarization of the linear polarized light (a) by 180°. <P>COPYRIGHT: (C)2007,JPO&INPIT |
