Patent ID: 7905646

Claim:
A lighting unit for a display panel comprising a light-guiding member, and, a first light source group and a second light source group in which a plurality of light emitting devices arranged adjacent to each of two terminal surfaces facing each other in said light-guiding member are aligned in a line or in a belt, wherein: the light-guiding member comprises a first light mixing area adjacent to the first light source group, a second light mixing area adjacent to the second light source group, and a light outputting area between the first light mixing area and the second light mixing area; in the first light mixing area and the second light mixing area, lights which enter from the plurality of light emitting devices configuring an adjacent light source group are mixed with each other, and lights which enter from a remote light source group and are mixed with each other are outputted to a display panel arranged at an obverse side of the light-guiding member through portions of a surface of the light-guiding member at the obverse side thereof corresponding to the first and second light mixing areas; in the light outputting area, a part of the lights mixed with each other are transmitted and the rest of the lights are outputted to the display panel through a portion of the surface of the light-guiding member at the obverse side thereof corresponding to the light outputting area; the light-guiding member is arranged in overlapping relation with the display panel so that both of the first light mixing area and the second light mixing area and the light outputting area thereof are arranged in overlapping relation with the display panel; a light control element is provided on the obverse side of the light-guiding member; the light control element is a transparent sheet having many prism surfaces on its surface, and a ridgeline of the prism surfaces is parallel to the arrangement direction (longitudinal direction) of the plurality of light emitting devices; among the lights which are outputted from the first light source group and enter in the light-guiding member, when assuming outputted light intensity per unit area in the surface of the light-guiding member of the lights which are outputted from the obverse side of the light-guiding member at the first light mixing area, the light outputting area, and the second light mixing area to be L011, L01, L012 respectively, and among the lights which are outputted from the second light source group and enter in the light-guiding member, when assuming outputted light intensity per unit area in the surface of the light-guiding member of the lights which are outputted from the obverse side of the light-guiding member at the first light mixing area, the light outputting area, and the second light mixing area to be L021, L02, L022 respectively, the relationships, L011<L01<L012, L021>L02>L022, L011<L021, and L012>L022, are satisfied.