Abstract: An overspeed prevention structure is disclosed herein. The overspeed prevention structure according to the present invention comprises a structural body having a curved convex upper surface; an external light source; and a plastic optical fiber embedded in the structural body and connected electrically to the external light source so as to emit the light outside the structural body.

Abstract: An aquatic light emitting device comprising a plurality of point light emitting units and a plurality of linear light emitting units is disclosed. The point light emitting unit comprises a floating member, a light source part, and a power supply part. The floating member includes a hollow body which has an internal space isolated from the outside so as to give buoyancy, one or more junction portions formed on an outer surface thereof, and has a light inlet opening formed on an upper part, and a string connected to a lower surface of the hollow body. The light source part is attached to the upper surface of the floating member, has an isolated internal space with light outlet openings provided at the upper and lower surfaces thereof, and a light source and a light source control circuit contained in the isolated internal space. The power supply part is located on the upper surface of the light source part and includes a solar cell.

Abstract: An aquatic light emitting device comprising a plurality of point light emitting units and a plurality of linear light emitting units is disclosed. The point light emitting unit comprises a floating member part, a light source part, and a power supply part. The floating member includes a hollow body which has an internal space isolated from the outside so as to give buoyancy, one or more junction portions formed on an outer surface thereof, and has a light inlet opening formed on an upper part, and a string connected to a lower surface of the hollow body. The light source part is attached to the upper surface of the floating member, has an isolated internal space with light outlet openings provided at the upper and lower surfaces thereof, and a light source and a light source control circuit contained in the isolated internal space. The power supply part is located on the upper surface of the light source part and includes a solar cell.

Abstract: An overspeed prevention structure is disclosed herein. The overspeed prevention structure according to the present invention comprises a structural body having a curved convex upper surface; an external light source; and a plastic optical fiber embedded in the structural body and connected electrically to the external light source so as to emit the light outside the structural body.