Proximity sensor system having a proximity sensor with a bipolar signal output
US6857321B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 3, 2001 |
| Grant date | Feb 22, 2005 |
| Priority date | — |
| Expiry date | Mar 3, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/102
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention relates to a proximity sensor system comprising a sensor generating two types of pulse signals having opposite polarities in order to detect two different, small, metallic objects and to distinguish the objects. The proximity sensor system can involve at least two metallic objects to be detected having different magnetic properties; a sensor comprising a magnetic core having a plurality of legs and a toroidal coil winding fitted and supported onto at least one of the legs of the magnetic core; and an electronic circuit processing output signals from the sensor. The sensor generates predetermined signals having opposite polarities when metallic objects pass in proximity to the sensor. Suitable metallic objects include those made of ferromagnetic metal and diamagnetic or paramagnetic metal. The sensor generates a positive pulse signal when the ferromagnetic metallic object passes by the sensor, and the sensor generates a negative pulse signal when the diamagnetic or paramagnetic metallic object passes by the sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.