Intrusion detection device
First Claim
1. An intrusion detection device comprising a radiation emitter arranged to project a beam of infrared radiation toward a field of view, means for receiving the reflected radiation of said beam reflected from said field of view, said beam receiving means including a deflecting means and a plurality of detector means, said deflecting means being arranged to divert said reflected beam onto a specific detector means determined by the distance from said device at which said beam has been reflected by said field of view, said receiving means arranged to generate a signal indicative of the distance from said device at which said beam has been reflected by said field of view during a selected time period, means for storing a reference signal which is indicative of the distance of reflection of said beam from said field of view during a reference time period, means for comparing said signal from said selected time period with said reference signal, and means for generating an output signal if said signal is different from said reference signal.
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Accused Products
Abstract
An intrusion detection device which comprises a radiation emitter arranged to project a beam of infrared radiation toward a field of view and means for receiving the radiation of the beam reflected from the field of view. The receiving means is arranged to generated a signal indicative of the distance from the device at which the beam has between reflected by the field of view during a selected time period. Means is also provided for storing a reference signal which is indicative of the distance of reflection of the beam from the field of view during a reference time period. Further means is provided for comparing a signal from a selected time period with the reference signal and for generating an output signal if the signal differs from the reference signal in a preselected manner.
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Citations
23 Claims
- 1. An intrusion detection device comprising a radiation emitter arranged to project a beam of infrared radiation toward a field of view, means for receiving the reflected radiation of said beam reflected from said field of view, said beam receiving means including a deflecting means and a plurality of detector means, said deflecting means being arranged to divert said reflected beam onto a specific detector means determined by the distance from said device at which said beam has been reflected by said field of view, said receiving means arranged to generate a signal indicative of the distance from said device at which said beam has been reflected by said field of view during a selected time period, means for storing a reference signal which is indicative of the distance of reflection of said beam from said field of view during a reference time period, means for comparing said signal from said selected time period with said reference signal, and means for generating an output signal if said signal is different from said reference signal.
- 11. An intrusion detection device comprising a head member which includes a plurality of infrared radiation emitters arranged to project successive pulses of infrared beams of radiation from said device, said beams of radiation being projected onto a plurality of fields of view from said head, a plurality of infrared radiation receiving means arranged to accept reflected radiation of said successive pulses of said infrared beams reflected from said fields of view, said plurality of receiving means and emitters being arranged in cooperating pairs with each emitter-receiving means pair arranged to include the same field of view and with each cooperating pair arranged to view a different field from other cooperating pairs, each of said receiving means comprising means arranged to direct the reflected radiation onto an array of photosensors responsive to infrared radiation, said photosensors being arranged to generate a photosignal related to the quantity of infrared radiation falling thereon, each of said receiving means arranged to generate a signal indicative of the distance from said device at which the pulse of said beam from the cooperating emitter has been reflected by the respective field of view during a selected time period, means for storing a reference signal which is indicative of the distance of reflection of said beam from said respective field of view during a reference time period, means for comparing said signal from said selected time period for that receiving means with said reference signal, and means for generating an output signal if said signal differs from said reference signal in a preselected manner.
Specification