Infrared intrusion detector with pyroelectric sensor and charge amplifier
US4418335A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 18, 1981 |
| Grant date | Nov 29, 1983 |
| Priority date | — |
| Expiry date | Sep 18, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S250/01
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An infrared intrusion detector, utilizing as a sensor element a pyroelectric detector element, accomplishes evaluation of the output signal of the detector element with a charge amplifier, for instance by means of a capacitive feedback coupled operational amplifier, the output signal of which is reset at certain time intervals. The evaluation circuit operates independently of the detector capacitance and therefore enables optimum utilization of the pyroelectrical properties. By virtue of the short-circuit operation and the low ohmic properties of the circuit there is obtained a particularly good non-sensitivity against external disturbances and low noise and increased sensitivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.