Intrusion detection device with extended field of view
US4876445A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 16, 1988 |
| Grant date | Oct 24, 1989 |
| Priority date | — |
| Expiry date | May 16, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S250/01
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An intrusion detection device which has an optically extended field of view substantially greater than 180 degrees is disclosed. The intrusion detection device includes a radiation sensor and an optical system for concentrating radiation onto the sensor from each of a plurality of discrete fields of view extending over a predetermined arc greater than 180 degrees. A lens system has a plurality of segments each with its own field of view. Reflectors within the field of view of each of a plurality of the lens segments are oriented to gather radiation from a predetermined field of view outside the field of view of the lens system and to reflect the gathered radiation onto the associated lens segment to be concentrated onto the sensor. Preferably, the segmented lens is a Fresnel lens system having an array of lens segments, each lens segment being angled with respect to the others so as to have its own discrete field of view, and each lens segment being positioned and angularly disposed with respect to the other lens segments so as to share a common focal point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.