| 摘要 |
The headlight has an incandescent lamp with an incandescent filament for main beam and an incandescent filament for dipped beam. The reflector has reflection regions which are in the shape of a paraboloid and have a common axis. The reflection region arranged above the reflector has a shorter focal length than the remaining reflection region of the reflector. Directly adjacent to the vertex opening, the reflection region arranged above the vertex opening has a section of area whose focal length is shorter than that of the remaining section of area of this reflection region. These two sections of area of the reflection region are connected by a coaxial section of area of the lateral surface of a conical frustum. The generating lines of the conical frustum are formed by the common tangents through the adjacent end points of the parabolic branches, produced in an axial longitudinal section, of both sections of area. In this case, the generating line of the conical frustum is so long that the focal point of the section of area having the shorter focal distance is arranged inside the incandescent filament for the main beam or, seen in the direction in which light exits, upstream of the incandescent filament for the main beam. The result is the provision of foreground (close-range) illumination over a wide area, in particular for vehicles used in construction and agriculture.
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