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AssigneeSwarco Futurit Verkehrssignal Systeme Ges m.b.H.
InventorsFranz Silhengst, Friedrich Peter Hofstadler, Alexander Otto
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An optical element for changeable traffic signs consisting of a light source, in particular, a light-emitting diode (LED), at least one converging lens and one diverging lens, which are arranged coaxially in a shared housing. The light exiting from the light source is captured as completely as possible by the converging lens, concentrated in a focal spot, which is preferably surrounded by a diaphragm and directed further onto the diverging lens which distributes it according to certain specifications. The refracting power of the diverging lens is dimensioned such that light exiting from it features a smaller angle of exit β than a prescribed limit angle α. The distance between the converging lens and the diverging lens is dimensioned such that sunlight incident from the outside at an angle γ greater than or equal to the limit angle α is completely blocked, either by the diaphragm or by absorption on the housing wall, so that no phantom light is generated.
Optical element for changeable signs, comprising a light-emitting source, (1), at least one converging lens (2) and one diverging lens (3), which are arranged in a shared housing (4), essentially coaxially with the geometrical axis (5) of the element, and of an angle of inclination α established to be directed upwards from the geometrical axis (5) in the direction of light emitted from the light source, wherein substantially all the light (6) exiting from the light source (1) is captured by the converging lens (2) and concentrated onto the diverging lens (3) arranged a defined distance away and deflected by the latter in the direction of observation in order to achieve a prescribed light distribution (8), characterized in that the converging lens (2) concentrates the beams of lightrays (7) exiting at each point of its surface facing the diverging lens (3), divergent by an angle δ, onto the diverging lens (3), that the diverging lens (3) is of such a design that substantially all the light beams (8) exiting from the diverging lens (3) lie at an inclination β below the angle of inclination α, and that the housing (4) is constructed as a tube-like sleeve around light source (1), converging lens (2) and diverging lens (3), is completely enclosed on its periphery and is provided on the inside with at least one of a light-absorbing color and structure.
Dependencies are inferred from the claim text.