摘要 |
A lighting unit is provided which comprises: a plurality of linear light sources arranged in parallel; light-guiding plates arranged along said light sources; light diffusion means arranged at the top of said light sources and light-guiding plates; and reflection means arranged at the bottom of the light sources; wherein said lighting unit is characterized in that the surface of each light-guiding plate is flat, in that the reverse side of the light-guiding plate includes an inclined face of a curvilinear shape that thins down as the inclined face is more distanced from the light source, and in that when a position relatively near the light source and a position relatively far from the light source, on the reverse side of the light-guiding plate, are inclined by thetan1 and thetaf1, respectively, the relationship of thetan1>=thetaf1 is satisfied and the angle-of-inclination of the thinnest portion on the reverse side of the light-guiding plate is 0 degrees. With this arrangement, supply of a thin lighting unit that is high in luminance and in the in-plane uniformity of luminance can be obtained.
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