| 摘要 |
A first optical-path changing layer is provided, on a front-face side of a rear-face side transparent substrate including a light source on one side face thereof. The first optical-path changing layer has a refractive index substantially equal to that of the transparent substrate, and includes predetermined protrusions and predetermined depressions. Further, a low refractive-index layer is provided on a front-face side of the first optical-path changing layer. The low refractive-index layer is in contact with the protrusions and the depressions of the first optical-path changing layer, and has a smaller refractive index than the refractive index of the first optical-path changing layer. Further, a second optical-path changing layer is provided on a rear-face side of the rear-face side transparent substrate. The second optical-path changing layer includes predetermined protrusions and predetermined depressions.
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