| 摘要 |
PURPOSE:To obtain a diffusing-type alarm lamp reduced in size and having small air resistance during traveling by constituting a diffusing radiating portion of a rotary elliptic reflecting surface, a light source placed at the first focus of the surface and a projection lens whose focus is positioned at a second focus of the rotary elliptic reflecting surface. CONSTITUTION:A reflecting mirror 9 fixed on a base 8 is opened forward, with its reflecting surface 10 exhibiting a rotary ellipse. A lamp 11 is supported at a rear summit of the reflecting mirror, and a filament 12 is located at a first focus F1 of the reflecting surface 10. Light 13, 13,... emitted from the filament 12 and reflected by the reflecting mirror 10 is therefore focused at a second focus F2 of the reflecting surface 10. A projection lens 14 supported on the base 8 so that it is located in front of the reflecting mirror 9 is formed like a fresnel lens, and the focus Fc of the projection lens 14 is located at the second focus F2 of the reflecting mirror 10. This permits a lamp to be reduced in size and air resistance during traveling without decreasing the number of utilized light beams. |
