| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lighting device, of which a visual field angle is restricted within a range from a normal of a display face to a desired limited irradiation angle, and a display with enough high brightness can be obtained at the limited field angle. <P>SOLUTION: A reflecting polarizing plate 3 equipped with a transmitting axis 3a transmitting a linear polarizing component and a reflecting axis reflecting a linear polarizing component having a polarizing face crossing it, and a prism sheet 4 equipped with a rugged face with a plurality of butted strips 4a arrayed in parallel arranged in turn with the butted strips 4a made to cross the transmitting axis 3a at a front side of a plane light-emitting element made by arranging a cold-cathode tube 1 in opposition to an end face of a light guide plate 2, while a (1/4) wavelength phase-contrast plate 5 and a light reflecting plate 6 are arranged in turn at a rear side of the plane light-emitting element, and a linear polarized light P1 transmitting the reflecting polarizing plate 3 and a linear polarized light P2 reflected and recurred there are condensed in a normal direction n by the prism sheet 4 to be shed in a direction of a liquid crystal display panel 7. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
