The invention relates to a light signal comprising a semiconductor light source and a converging optical unit for representing signal aspects, in particular on rail-bound traffic routes.
The explanations below substantially relate to luminous signs or light signals for representing signal aspects on rail-bound traffic routes, without the claimed inventive subject matter being intended to be restricted to this application.
In the case of the four light signals of known design as illustrated schematically in
The invention is based on the object of simplifying a light signal of the generic type, wherein, in particular, the type diversity of the required semiconductor light sources is to be reduced.
According to the invention, the object is achieved by virtue of the fact that the semiconductor light source is embodied as a white point light source, wherein a signal-aspect-specific color filter is provided in the aperture region of the point light source.
As a result of the reduction to point light sources of the white light type, monochrome semiconductor light sources become dispensable. Besides the independence of individual manufacturers, this results in a significant cost reduction as a result of component reduction in the driver assemblies. The expected uniform lifetime of the white point light source is also advantageous, whereas monochrome semiconductor light sources have very different lifetimes depending on the required energization for achieving the minimum axial light intensity.
In principle, it should be expected that in the future the achievable luminous efficiency in the case of point light sources, in particular on the basis of HLED for white light, will increase further. This means that even more powerful white HLEDs used in the future can be energized in a reduced fashion for the same light intensity, whereby the lifetime of the HLEDs increases.
In accordance with one embodiment, each signal aspect is assigned a point light source comprising a white LED or a white HLED—high-current LED. Depending on the signal aspect, a corresponding color filter is fixedly arranged between the point light source and the converging optical unit.
In the case of light signals designed for a plurality of signal aspects, a component and structural size reduction can be achieved by virtue of the fact that, in accordance with another embodiment, the signal aspects are assigned a common point light source comprising a white LED or a white HLED and a common converging optical unit, wherein an automatic changer for positioning signal-aspect-specific color filters in the aperture region of the point light source is provided.
Preferably, in accordance with one embodiment, the color filter is embodied as a polycarbonate color filter film. These very cost-effective color films are used very often in the field of photography. Moreover, polycarbonate color filter films exhibit particularly high thermal stability and long-term stability, wherein individual color films or a plurality of color films combined with one another, in the use of the HLED white light source, can generate approximately any desired color locus in the emission. In this case, the filter films to be used are only dependent on the spectral composition of the axial light component and can be very precisely determined and optimized in accordance with the spectral properties of the filter films. In this case, the transmittance of the color filter films is comparable to the transmittance of corresponding color glass sheets used in the case of incandescent lamp light sources.
The invention is explained in greater detail below with reference to illustrations in figures, in which:
In contrast to the four light signals described above and illustrated in
Number | Date | Country | Kind |
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10 2009 039 703 | Aug 2009 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2010/060887 | 7/27/2010 | WO | 00 | 2/29/2012 |
Publishing Document | Publishing Date | Country | Kind |
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WO2011/023480 | 3/3/2011 | WO | A |
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