Suppressed transient uniform detection sensitivity pir detector
US4875029A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1987 |
| Grant date | Oct 17, 1989 |
| Priority date | — |
| Expiry date | Dec 30, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S250/01
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A passive analog equalizer is connected to the output of an infrared detector to provide increasing pyroelectric detector sensitivity with increasing target frequency in order to provide a detection sensitivity which is substantially flat over the target velocity range of interest. An interruptable modulator is connected to the equalized pyroelectric detector signal to shift its frequency upwardly in order to provide negligible drift, fast recovery from transients, and the ability to quickly shut down the modulator when a transient occurs. A transient detector is operative in response to transients in the pyroelectric detector output signal to provide a window during which the modulator is interrupted in order to prevent transient induced false alarms.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.