Sliding door sensor
First Claim
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1. A door sensor comprising:
- housing means;
first emitter means disposed in said housing means comprising a first array of IR emitters defining a first detection zone;
second emitter means disposed in said housing means comprising a second array of IR emitters defining a second detection zone;
first detector means disposed in said housing means for detecting radiation from said first zone;
second detector means disposed in said housing means for detecting radiation from said second zone;
first converter means responsive to said first detector means for generating a first pulse train having a frequency proportional to the detected radiation;
second converter means responsive to said second detector means for generating a second pulse train having a frequency proportional to the detected radiation;
first microprocessor means responsive to said first pulse train for identifying a target in said first zone and generating a first output signal indicative thereof;
second microprocessor means responsive to said second pulse train for identifying a target in said second zone and generating a second output signal indicative thereof, said second microprocessor means comprising identification means comprising reference means for establishing a reference value, detector count means for obtaining a count indicative of detected radiation, and comparison means for comparing said detector count to said reference value, and background adjustment means for incrementally adjusting said reference value by decreasing or increasing the reference value by a sequence of decreasing positive difference counts determined by a difference between a preceding count value and a preceding reference value so that said reference value incrementally converges toward said count value.
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Abstract
A sliding door sensor employs two arrays of IR emitters which are pulsed to provide an approach detection zone and a threshold detection zone. Radiation reflected from the detection zones is converted to signals which are processed in microprocessors. The sensor periodically automatically adjusts for changes in background. Both presence and motion detection is provided. The sensor also detects dark objects.
112 Citations
23 Claims
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1. A door sensor comprising:
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housing means; first emitter means disposed in said housing means comprising a first array of IR emitters defining a first detection zone; second emitter means disposed in said housing means comprising a second array of IR emitters defining a second detection zone; first detector means disposed in said housing means for detecting radiation from said first zone; second detector means disposed in said housing means for detecting radiation from said second zone; first converter means responsive to said first detector means for generating a first pulse train having a frequency proportional to the detected radiation; second converter means responsive to said second detector means for generating a second pulse train having a frequency proportional to the detected radiation; first microprocessor means responsive to said first pulse train for identifying a target in said first zone and generating a first output signal indicative thereof; second microprocessor means responsive to said second pulse train for identifying a target in said second zone and generating a second output signal indicative thereof, said second microprocessor means comprising identification means comprising reference means for establishing a reference value, detector count means for obtaining a count indicative of detected radiation, and comparison means for comparing said detector count to said reference value, and background adjustment means for incrementally adjusting said reference value by decreasing or increasing the reference value by a sequence of decreasing positive difference counts determined by a difference between a preceding count value and a preceding reference value so that said reference value incrementally converges toward said count value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A door sensor comprising:
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housing means; first emitter means disposed in said housing means comprising a first array of IR emitters defining an approach detection zone; second emitter means disposed in said housing means comprising a second array of IR emitters defining a threshold detection zone; first detector means disposed in said housing means for detecting radiation from said approach zone; second detector means disposed in said housing means for detecting radiation from said threshold zone; first converter means responsive to said first detector means for generating a first pulse train having a frequency proportional to the detected radiation; second converter means responsive to said second detector means for generating a second pulse train having a frequency proportional to the detected radiation; first microprocessor means responsive to said first pulse train for identifying a target in said approach zone and generating a first output signal indicative thereof; second microprocessor means responsive to said second pulse train for identifying a bright or a dark target in said threshold zone and generating a corresponding bright or dark signal, said second microprocessor means comprising identification means for identifying a target which causes radiation detected by said second detector means to have a detected count value which is either greater or less than a pre-established reference value by at least a pre-established positive sensitivity value and generating a second output signal indicative thereof; and output means responsive to said first and second signals for producing an operator signal. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19)
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20. A door sensor and door system comprising:
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automatic sliding door means comprising at least one door traversable across a threshold; housing means disposed generally above said threshold; first emitter means disposed in said housing means comprising a first array of IR emitters defining an approach detection zone generally frontally spaced from said threshold; second emitter means disposed in said housing means comprising a second array of IR emitters defining a threshold detecting zone intersecting said approach detection zone and extending at opposing sides of said threshold; first detector means disposed in said housing means for detecting radiation from said approach zone; second detector means disposed in said housing means for detecting radiation from said threshold zone; first converter means responsive to said first detector means for generating a first pulse train having a frequency proportional to the detected radiation; second converter means responsive to said second detector means for generating a second pulse train having a frequency proportional to the detected radiation; first programmable microprocessor means responsive to said first pulse train for identifying a target in said approach zone by periodically counting pulses in said first pulse train, processing signals and generating a first output signal indicative thereof; second programmable microprocessor means responsive to said second pulse train for identifying a target in said threshold zone by periodically counting pulses in said second pulse train, processing signals and generating a second output signal indicative thereof; each said microprocessor means comprising reference means for automatically establishing a reference value corresponding to the background radiation in the corresponding detection zone and reference adjustment means for periodically adjusting the reference value to compensate for changes in the background radiation, one said microprocessor means comprising identification means comprising reference means for establishing a reference count, detector count means for determining a count indicative of detected radiation, comparison means for comparing said detector count to said reference count, and background adjustment means for incrementally adjusting said reference value by decreasing or increasing the reference value by a sequence of decreasing positive difference counts determined by a difference between a preceeding count value and a preceeding reference value so that said reference value incrementally converges toward said count value. - View Dependent Claims (21, 22, 23)
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Specification