Sensor using the capacitive measuring principle

US7545154B2 · kind B2 · utility

Assignee

• MICRO-EPSILON-MESSTECHNIK GMBH & CO. KG · DE

Inventors

• Manfred Wagner · Triftern, DE
• Norbert Reindl · Fürstenzell, DE

Key dates

• Filing date: Jun 20, 2007
• Grant date: Jun 9, 2009
• Expiry date: Jun 20, 2027

Classification

• Technology area (CPC E): Fixed Constructions
• CPC primary: E05F15/46
• WIPO field: Civil engineering
• WIPO sector: Other fields

Abstract

The invention relates to a sensor which uses the capacitive measuring principle which is used to detect the proximity of a dielectric medium, preferably for detecting a human body part, which is used in an anti-pinching system. The sensor includes a capacitor and an evaluation electronic system. The variation of the capacity of the capacitor, which is caused by the medium, can be measured. The capacitor, which can establish a distinction between a human body part or a solid and water and/or humidity, is characterized in that the capacitor can be operated in a successive manner by at least two different frequencies and/or at least two different pulse duty factors by using the different ratio of said elements in a variable electric field. The invention also relates to a corresponding method.