| 摘要 |
PROBLEM TO BE SOLVED: To reduce manufacturing cost as well as improve light transmission efficiency and productivity. SOLUTION: A large number of resin-made cores 30 are bundled by integral formation with a bundle member 35 made of resin. Since there is almost no difference between a linear expansion coefficient of the resin-made cores 30 and a linear expansion coefficient of the resin-made bundle member 35, almost no distortion generating due to thermal shrinkage, thermal expansion, or the like is caused in the cores 30. There is, therefore no fear that light transmission efficiency of the cores 30 is lowered, thereby providing an improvement on the light transmission efficiency. Because the large number of cores 30 and the bundle member 35 are integrally formed, work, such as temporary fixing with an adhesive or fixing with a metal-made bundle member, becomes unnecessary, thus productivity being improved compared with a conventional light guide. A manufacturing cost is also lowered in comparison with a conventional light guide, because an adhesive or a metal-made bundle member is unnecessary. |
