Infrared motion alarm

US4752769A · kind A · utility

Assignee

• Heimann GmbH · DE

Inventors

• Gerhard Knaup · Lorsch, DE
• Fred Plotz · Wiesbaden, DE
• Norbert Schaaf · Wiesbaden, DE

Key dates

• Filing date: Sep 2, 1986
• Grant date: Jun 21, 1988
• Expiry date: Sep 2, 2006

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S250/01
• WIPO field: Control
• WIPO sector: Instruments

Abstract

The invention is directed to an infrared motion alarm characterized by an infrared detector and an optical arrangement before the detector in the radiation direction for focussing the infrared radiation onto the detector. The optical arrangement is formed by a mirror arrangement and by a lens arrangement with the mirrors being on different levels so the different beam paths are being detected to prevent an intruder from crawling under the infrared detection beam paths.