Polymeric security window with an integrated intrusion detector
US4972176A · kind A · utility
26Cited by
6References
15Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Sep 15, 1989 |
| Grant date | Nov 20, 1990 |
| Priority date | — |
| Expiry date | Sep 15, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B13/04
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The security window is a laminated pair of polymeric panels having electrically conductive rods sandwiched therebetween. Glass fibers, having electrically conductive coatings, extend from edge to edge of the plastic window panels and are distributed in the rods which substantially cover the entire window area. The index of refraction of the coated glass fibers is as identical as possible to that of the surrounding plastics, making the electrically conductive rods substantially invisible. The conductive rods are connected in series. The resistance characteristics of the circuit are monitored to detect damage to the window.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.