Accession Number:
ADD014515
Title:
Optical Motion Detector Detecting Visible and Near Infrared Light.
Descriptive Note:
Patent, Filed 31 May 89, patented 20 Feb 90,
Corporate Author:
DEPARTMENT OF THE NAVY WASHINGTON DC
Personal Author(s):
Report Date:
1990-02-20
Pagination or Media Count:
10.0
Abstract:
An optical motion detector detects changes in scene lighting indicative of motion and is also capable of detecting surveillance by active night vision devices using near-infrared light. The detector includes two photodetectors which each provide data to a signal processing network. One photodetector is sensitive to visible light the other to near-infrared light. Both signal processing networks are identical and include a sample-and-hold, a comparator network, and a pulse stretcher. The output of a photodetector is provided to the sample-and-hold and comparator network. The comparator network compares a voltage corresponding to the instantaneously detected ambient lighting scene with a voltage corresponding to a reference lighting scene. The pulse stretcher receives the output of the comparator network and in turn provides an output to a logical processor. The logical processor compares the outputs of both signal processing networks and provides an output indicating surveillance with near-infrared light. The logical processor also indicates any perturbations in intensities of incandescent and fluorescent light. Patents. edc
Descriptors:
- *INFRARED DETECTORS
- *OPTICAL DETECTORS
- *PATENTS
- *PHOTODETECTORS
- *SIGNAL PROCESSING
- CHANGE DETECTION
- COMPARATORS
- FLUORESCENCE
- ILLUMINATION
- INDICATORS
- INFRARED RADIATION
- INFRARED SURVEILLANCE
- INTENSITY
- LIGHT
- MOTION
- NEAR INFRARED RADIATION
- NETWORKS
- NIGHT VISION DEVICES
- OUTPUT
- PERTURBATIONS
- PULSE SPACING MODULATION
- SENSITIVITY
- SURVEILLANCE
- VISIBLE SPECTRA
Subject Categories:
- Optical Detection and Detectors
- Infrared Detection and Detectors