Abstract: Light distribution characteristics are defined which define a correspondence relation between the position of a reflection point on a reference plane and the position of an image of a light source. In accordance with the light distribution characteristics, a path line in the reference plane is determined. A profile curve for each of a plurality of sampling points dispersibly distributed on the path line, is determined in accordance with the light distribution characteristics, the profile curve passing through the sampling point and corresponding to the topological shape of a reflecting surface to be determined. As the reflection point moves along the profile curve, the image of the light source moves in the direction crossing the reference plane in accordance with the light distribution characteristics. The topological shape of the reflecting surface is determined in accordance with the profile curve determined for each sampling point.

Abstract: An improved signal lamp for a vehicle is composed of a plurality of dome type light emitting diodes and a plurality of reflective mirrors arranged corresponding to the light emitting diodes. Each of the reflective mirrors is designed in the shape of a rotational parabolic surface whose focus is located at the position coincident to the foremost end of the corresponding light emitting diode or at the position in the vicinity of the foremost end of the corresponding light emitting diode. The rotational parabolic surface is configured such that a virtual light source appearing on each light emitting diode is located at the position coincident with the focus of the corresponding reflective mirror or at the position in the vicinity of the focus of the corresponding reflective mirror.