System and method for monitoring vehicular traffic with a laser rangefinding and speed measurement device utilizing a shaped divergent laser beam pattern
First Claim
1. A traffic monitoring device for vehicle speed determination comprising:
- a source of laser light pulses;
a lens for causing light emitted by said source of laser light to diverge toward said vehicle, said light presenting a substantially oval beam pattern having a maximum width in a distal portion of the oval beam pattern and minimum width in a proximal portion of the oval beam pattern; and
a mask associated with said source of laser light and said lens for at least partially precluding some portion of said light from exiting said lens and delineating divergent edge portions of said beam pattern, wherein said vehicle speed is determined by a time of flight calculation of said laser light pulses.
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Abstract
A system and method for monitoring vehicular traffic with a laser rangefinding and speed measurement device utilizing a shaped divergent laser beam pattern. In accordance with the present invention, a traffic monitoring device is disclosed which comprises a light emitting diode having a die element producing an asymmetric beam pattern, an aperture for at least partially precluding some portion of the beam pattern in a first direction while allowing the beam pattern in a second orthogonal direction to pass therethrough and a lens associated with the aperture for causing the laser beam exiting the aperture to diverge providing a cone-like beam of laser energy.
27 Citations
20 Claims
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1. A traffic monitoring device for vehicle speed determination comprising:
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a source of laser light pulses; a lens for causing light emitted by said source of laser light to diverge toward said vehicle, said light presenting a substantially oval beam pattern having a maximum width in a distal portion of the oval beam pattern and minimum width in a proximal portion of the oval beam pattern; and a mask associated with said source of laser light and said lens for at least partially precluding some portion of said light from exiting said lens and delineating divergent edge portions of said beam pattern, wherein said vehicle speed is determined by a time of flight calculation of said laser light pulses. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A traffic monitoring device for vehicle speed determination comprising:
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a light emitting diode having a die element producing an asymmetric beam pattern of laser light pulses having a greater divergence in a first direction than in a second orthogonal direction; a lens associated with said light emitting diode for causing said laser light pulses to diverge toward a vehicle, said beam pattern being substantially oval in shape having a maximum width in a distal portion of the oval beam pattern and minimum width in a proximal portion of the oval beam pattern; and a mask associated with said light emitting diode and said lens for at least partially precluding some portion of said light from exiting said lens and delineating divergent edge portions of said beam pattern, wherein said vehicle speed is determined by a time of flight calculation of said laser light pulses. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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Specification