Proximity sensor
US5801340A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 29, 1995 |
| Grant date | Sep 1, 1998 |
| Priority date | — |
| Expiry date | Jun 29, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/960765
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An improved capacitive sensor for detecting the presence of objects in a sensing region. The sensor is a multilayer structure with alternating layer of condutive and insulating materials. The sensor structure has three electrodes: a touch plate, a guard layer, a ground plane, each of which are separated from each other by insulating layers. The sensor is operated by detection electronic circuitry which function in a either a self excited mode or an externally excited mode. This sensor is capable of detecting objects in a sensing region several feet away from the sensing surface and is particularly suitable for automobile applications, such as detecting potentially jamming objects in power (auto-closing) windows, doors, and the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.