| 摘要 |
PROBLEM TO BE SOLVED: To obtain an optical plate including more than one columnar structure whose internal refractive index is larger than that at the border of the columnar structure by providing a cladding structure which has a cladding refractive index smaller than a core refractive index. SOLUTION: The columnar structure which forms a core area 64 is extended substantially from a light entrance surface 30 to a light exit surface 32. At the time of use, light normally enters the core area 64 from the light entrance surface 30, travels in the core area 64, and exits normally from the light exit 32. The core area 64 has a larger refractive index enough to internally reflect the light entering the core area 64 than the cladding area 66. Consequently, the substrate can be formed including columnar structures which each have the refractive index larger in itself than at its border and has its border prescribed by the discontinuity of the refractive index. |
