METHOD TO IMPROVE WHITE LIGHT IMMUNITY OF INFRARED MOTION DETECTORS
First Claim
1. ) A motion detection system for detecting a presence of a moving object within a secure area, the system comprising:
- a first sensor responsive to light in a first range of wavelengths in the secure area, the first sensor generating a first output signal indicative of a first detected parameter of the light in the first range of wavelengths;
a second sensor proximate to the first sensor, the second sensor being responsive to light in a second range of wavelengths in the secure area; and
a logic unit for compensating the first output signal based in part upon a reference signal indicative of a second parameter of the light in the second range of wavelengths.
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Accused Products
Abstract
The present invention provides a system and method for improved white light immunity for 1R motion sensors. The system comprises a first sensor responsive to light in a first range of wavelengths in the secure area, the first sensor generating a first output signal indicative of a first detected parameter of the light in the first range of wavelengths, a second sensor proximate to the first sensor, the second sensor being responsive to light in a second range of wavelengths in the secure area, and a logic unit for compensating the first output signal based in part upon a reference signal indicative of a second parameter of the light in the second range of wavelengths. The first sensor is a pyroelectric sensor and the second sensor is a visible light sensor. The second parameter comprises an intensity value of the light in the second range of wavelengths, wherein the reference signal is indicative of a differentiation of said intensity value with respect to time. The system further comprises an alarm generation unit to generate an alarm if the first signal exceeds a first threshold value, the first threshold value being a function of a baseline of the first signal. The method comprises generating at a first sensor a first output signal indicative of a first detected parameter of light in a first range of wavelengths, and compensating the first output signal based in part upon a reference signal indicative of a second parameter of light in a second range of wavelengths.
15 Citations
30 Claims
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1. ) A motion detection system for detecting a presence of a moving object within a secure area, the system comprising:
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a first sensor responsive to light in a first range of wavelengths in the secure area, the first sensor generating a first output signal indicative of a first detected parameter of the light in the first range of wavelengths; a second sensor proximate to the first sensor, the second sensor being responsive to light in a second range of wavelengths in the secure area; and a logic unit for compensating the first output signal based in part upon a reference signal indicative of a second parameter of the light in the second range of wavelengths. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. ) A method for detecting a presence of a moving object within a secure area, the method comprising:
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generating at a first sensor a first output signal indicative of a first detected parameter of light in a first range of wavelengths; and compensating the first output signal based in part upon a reference signal indicative of a second parameter of light in a second range of wavelengths. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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Specification