| 摘要 |
A beacon comprises a light source such as LED 4 inside a cylindrical fresnel lens 6 and a conical reflector 7 facing the LED so that emitted light is distributed about their common axis in azimuth and the reflected light augments that refracted by the lens. Lens 6 can increase in diameter smoothly away from the light source and the cone angle of reflector 7 can increase smoothly away fro its vertex 8. The beacon can comprise a transparent, coloured or translucent cover 2 having ribs. Cover 2 encloses the lens, reflector and light source, which can be four LEDs (fig 6,14) in an array. The beacon may flash and be used on an emergency or service vehicle. |
