Micropower capacitance-based proximity sensor
US6307384A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 1999 |
| Grant date | Oct 23, 2001 |
| Priority date | — |
| Expiry date | Jan 7, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/088
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention is a proximity detector for an electronic device. The proximity detector utilizes two capacitors which share a common electrode. The two capacitors are located on the housing of the electronic device. The capacitors are arranged so that when the electronic device is used in its normal orientation, a portion of the operator's body will occlude one of the capacitors, but not the other. The close proximity of the operator's body will change the electric field surrounding the capacitor. Thus, the capacitance of the occluded capacitor will be different than the unencumbered capacitor. A detection circuit is coupled to the capacitors and to the power supply of the device. The circuit uses very little power, and maintains the electronic device in a standby or powered down mode. Only when the circuit detects a difference in the capacitance generated by the two capacitors, will it allow full power to be delivered to the electronic device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.