| 摘要 |
An improved capacitive sensor for detecting the presence of objects in a sensing region. The sensor is a multilayer structure with alternating layers of conductive and insulating materials. The sensor structure has three electrodes; a touch pla te (25), a guard layer (15), and a ground plane (5), each of which are separated from each other by insulating layers (20, 10). The sensor is operated by detection electronic circuitry which function in 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.
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