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Ellipsoid Headlamps
Halogen and xenon-lens headlight, small escape surface |
Ellipsoid headlamps should create a dipped beam with an equal distribution of the light, featuring an exact light/dark boundary, and as few scattered light as possible. With these advantages the system is
predestinated to work together with Xenon-lamps. Due to the small diameter of the outcoming beam these headlamps can be integrated more
easily into the car design.
Freely malleable surfaces in the reflector |
The Paraboloid develops its reflection shape by rotation of a parabola, for the ellipsoid it is an ellipse. 'DE' stands for triple ellipsoid. The curvature of the ellipsoid is not steady outwardly, but changes in three cracks.
Due to the computer-controlled manufacturing of plastic reflectors they can have, in principle, also endlessly many gradations. Without shield all rays would be guided, in principle through the lens which is in diameter
much smaller.
The rays are heavily bundled at the lens |
It is special for ellipsoids to concentrate half of the light rays with a second focussing point. A shade - situated close to this second focussing point - creates a very precise light/dark boundary. At last, this beam, which
has a very small diameter, passes a special lens and is spread homogeneously onto the road. The diameter of the ray of light created in the ellipsoid is much smaller as compared to the light rays in a paraboloid or
stepped reflector. Beyond the final lense the diameter increases.
Shield may be tipped for driving on the left-hand side |
If you look at the top drawing, the shield must intercept only the rays which would strike below in the middle of the lens, because they would be deflected upwards. On top this looks as if it would be a quarter of the total
light, spatially, however, it is only the edge of the light cone. On the illustration you can recognize that if this shield is tipped to the other side the headlight can also be adapted to left-hand traffic. There is also the
possibility to switch over from the interior. 05/11
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