수중 가시화 구명줄 시스템 개발에 관한 연구

Abstract

Underwater rescue-ropes have been used for the underwater activities of divers such as lifesaving, filming, investigation and exploration and for securing their return paths. Studies have been conducted to visualize rescue-rope by applying an optical fiber and light emitting diode(LED) to pre-existing non-luminous ropes made of nylon, polypropylene or polyethylene. Furthermore, previous results showed that the visualized ropes could be used for underwater experiments. However, further studies on the reduction of the heat radiated by the low driving current of the LED and an efficient utilization of luminous flux are necessary, as the optical fiber used in the previous study would be damaged by the radiation of the light source. Therefore, this study was conducted to utilize the electrical and optical features of the LED and the optical fiber and to develop a high luminance underwater rescue-rope that is stable for long-term operation. To increase the luminance of underwater rescue-ropes, the three methods were the placement of an optimal light concentrator between the LED light source and the optical fiber, the control of the shielding and reflection of the optical fiber jacket and the application of a reflector at the end of the optical fiber. The light concentrator increased the luminous flux focused on the core by 660 % and the auxiliary jackets increased the surface luminance by 280 %. In addition, the reflector increased the surface luminance by a maximum of 430 %. The study result showed that the surface luminance of the optical fiber was the same as that in the previous study at only half the driving current i.e., 5 A, whereas its maximum luminance was increased by 180 %.