| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a buried beacon light which allows the preferred application of a prism having total reflection characteristics to the light that is required to be liquid tight. <P>SOLUTION: The prism 39 is covered almost entirely with a packing 50 to keep liquid tightness. However, a protective surface 51 opposite to a reflection surface 42 has a plurality of irregular portions 53 which are partially in contact with an interface 42a of the reflection surface 42. Because of this, the reflection surface 42 does not significantly lose its total reflection characteristics, so that the prism 39 having the total reflection characteristics can be used efficiently in the buried beacon light 11 required to be liquid tight. <P>COPYRIGHT: (C)2009,JPO&INPIT |
