| 摘要 |
PURPOSE:To increase incident light from a light source and to increase the light emission brightness of the other terminal with a normal diameter by expanding the terminal section of respective bundle optical fibers. CONSTITUTION:The section of an optical fiber becomes random and expands when heated to temperature which is 10-30 deg.C higher than its softening point because of the directions of its molecules. A multiple optical fiber 1 consists of plural bundled optical fibers 2 and seven plastic optical fibers are bundled in this case. The section of each optical fiber 2 is expanded at the terminal part 3 of this multiple optical fiber to make clad layers 4 contact one another so that the diameter of the terminal part 3 is nearly equal to the diameter when the seven optical fibers are bundled closely, and the end surface 5 is cut and ground at right angles to the optical axis. When an LED whose irradiation area is equal to the area of the end surface 5 is set as a light source opposite the end surface 5, incident light increases as much as the section of the core 6 expands, so light with high brightness is obtained at the other terminal 7 with the normal diameter. Not only the improvement of the brightness, but also the uniformity of the brightness among the respective optical fibers are obtained, and the light source is reducible in size. |
