Optical smoke detector

US5451931A · kind A · utility

Assignee

• Cerberus AG · CH

Inventors

• Kurt Muller · Zürich, CH
• Peter Ryser · Männedorf, CH
• Dieter Wieser · Küsnacht (ZH), CH
• Rino E. Kunz · Bülach, CH
• Markus Rossi · Jona, CH
• Michael T. Gale · Wettswil, CH

Key dates

• Filing date: Sep 14, 1993
• Grant date: Sep 19, 1995
• Expiry date: Sep 14, 2013

Classification

• Technology area (CPC G): Physics
• CPC primary: G08B17/113
• WIPO field: Control
• WIPO sector: Instruments

Abstract

Optical smoke detectors such as extinction smoke detectors and scattered-light smoke detectors include a radiation source, a radiation detector or receiver, and a measurement volume which is in communication with ambient atmosphere and which is traversed by a light path from the radiation source to the radiation receiver. For compactness and simplicity, such an optical smoke detector is provided with a planar-optical element in the optical path. Suitable as planar-optical elements are diffractive elements, e.g., holographic-optical elements (HOE), and micro-Fresnel elements (MFE), e.g., micro-Fresnel reflectors (MFR).