| 摘要 |
PROBLEM TO BE SOLVED: To provide a light guide that enables emissive light quantity to be increased in a simple method at a low cost. SOLUTION: The optical fiber 1 for a light guide made of a plastic material is composed of a light entrance part 2, an intermediate part 3, a light guiding part 4 and a light exit part 5 in this order from the base end. The outer diameter of the light guiding part 4 is almost equal to that of the light exit part 5 over the whole length. The light entrance part 2 has an expanded outer diameter compared with the light guiding part 4. This light entrance part 2 is formed by a thermal process. In particular, it is formed by inserting the base end of a plastic-made primary coated optical fiber into a heating tube, heating the tube at 80-300°C for example, softening and deforming the primary coated optical fiber inside. COPYRIGHT: (C)2003,JPO |
