PIR motion sensor utilizing sum and difference sensor signals
US7183912B2 · kind B2 · utility
20Cited by
11References
12Claims
0Family size
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Key dates
| Filing date | Apr 1, 2005 |
| Grant date | Feb 27, 2007 |
| Priority date | — |
| Expiry date | Sep 3, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B29/24
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A passive infrared sensor has two detector elements, each of which has a positive part and a negative part, with each detector element generating respective first and second signals. The signals are added together to render a “sum” signal and are also subtracted one from the other to render a “difference” signal, and a moving object is indicated only when the “sum” signal has a frequency different than the frequency of the “difference” signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.