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Optical sight system for the detection and recording of infringements of the road traffic regulations, using a laser

  • US 4,902,889 A
  • Filed: 08/11/1988
  • Issued: 02/20/1990
  • Est. Priority Date: 08/25/1987
  • Status: Expired due to Term
First Claim
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1. The traffic violation detection and recordation arrangement, comprising:

  • a plurality of optical sights, each optical sight including a laser emitter having a central axis and a photodiode receiver having a central axis, said laser emitter and photodiode receiver being arranged co-axially, said photodiode receiver including a photodiode sensing changes in light reflected from objects passing in front of a path of each associated laser emitter, and emitting a photodiode signal representative of the change in light sensed;

    power supply means including a power supply circuit associated with each laser emitter for generating a high frequency pulse laser emission, each emission having an emission duration which is much smaller than the duration between emissions;

    a tubular optical screen, connected to said laser, an optical concentrating and focusing assembly being connected to said tubular optical screen;

    photodiode optical concentrating means, arranged coaxial with said tubular optical screen, for concentrating and uniformly distributing incoming light on the photodiode;

    metallic screening means encompassing said photodiode, said screening means including an opening for receiving concentrated, distributed incoming light which has passed through said photodiode optical concentrating means, said screening means for shielding said photodiode receiver from external disturbances and disturbances generated by said power supply means and said laser emitter;

    photodiode signal amplification and processing means for amplifying said photodiode signal from an associated photodiode and processing said photodiode signal, including a preamplifier connected to said photodiode, a signal detector connected to said preamplifier, a differential amplifier for comparing the signal and a signal representative of background noise, gain control circuit means for controlling the gain on an average signal and trigger means for generating a signal by comparison with a reference and a timing value.

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