| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a display device with which a display mode to prevent peeping by restricting a viewing angle, and a display mode in which a display is simultaneously viewed with a great many people without restriction of the viewing angle, are freely and easily switched between each other, and a backlight used therefor. <P>SOLUTION: A backlight unit 2 is arranged on the rear side of a liquid crystal display element 1. In the backlight unit 2, an optical rotatory element 22 composed of a plurality of (λ/2) retardation films 22b evenly spaced and arranged in a standing condition with transparent bodies 22a interposed in between is disposed on the light emitting front face 21b side of a light guide plate 21, and a light source unit 26 is placed opposite to an end face 21a to be a light incident plane. The light source unit 26 is constructed by alternately arranging a plurality of light emitting diodes 24a to be first light sources and a plurality of light emitting diodes 24b to be second light sources in proximity and in a row arrangement along the light incident plane 21a, and arranging a polarizing plate 25 on the light emitting side of the light emitting diodes 24a being the first light sources. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
