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US 2004/0175232 A1Published application
Emissive highway markers
OwnerCharles Eric Hunter, Drew G. Narayaninventors
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Abstract
A highway marker comprising an emissive device positioned on a highway, wherein said emissive device emits electromagnetic radiation.
Claims16
A highway marker comprising:
- a housing;
- a plurality of LED's mounted in the housing, emitting electromagnetic radiation;
- a photodetector generating a signal responsive to an ambient light condition surrounding the housing;
- and
- a control circuit responsive to the photodetector signal to control the electromagnetic radiation from at east one LED to emit radiation of a predetermined color as perceived by the human eye according to the spectral sensitivity of the human eye for the ambient light condition.
2 more elements
A highway marker comprising:
- a plurality of LED's;
- a photodetector generating a signal responsive to ambient light condition;
- and
- means for adjusting the wavelength of emitted electromagnetic radiation of at least one LED to maintain a predetermined color as perceived by the human eye according to the spectral sensitivity of the human eye for the ambient light condition.
1 more element
Dependencies are inferred from the claim text.