| 摘要 |
PROBLEM TO BE SOLVED: To carry out uniform illumination while realizing a high luminance by a small-sized and light plane-like illumination device. SOLUTION: An emitted light L from a light emitting diode 4 is refracted when it passes through a prism sheet 5, a directivity is relaxed and a radiation range is enlarged to a wider range. As a result, an emission distribution pattern A of the light is lied on an almost whole area of the transparent substrate 2. Thus, an incident light to the transparent substrate 2 is refracted by a groove 2a and uniformly illuminates a liquid crystal element adjacent to a lower surface of the transparent substrate 2. |
