Lens arrangement for intrusion detection device
US5311024A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 1992 |
| Grant date | May 10, 1994 |
| Priority date | — |
| Expiry date | Mar 11, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S250/01
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Fresnel lens elements in a lens grouping and mounted in a fixed relationship to a detector, to define a 360.degree. field of view for use in a sensor for passive detection of infrared radiation. Lens elements of the lens grouping can be selected by masking other lens elements, to leave a lens array defining a particular pattern of detection for a desired application. By masking certain of the lenses of the lens grouping, wide angle three-dimensional or fan-like planar curtain patterns of detection are obtained for use of the sensor in either a wall-mounted or ceiling-mounted installation, and vertical curtains of coverage can be obtained using ceiling-mounted installation. Lens elements of different sizes and focal lengths are arranged to gather ample radiation for detection of distant intruders in certain directions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.