Wireless key system and key location determination method
US8872620B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 2011 |
| Grant date | Oct 28, 2014 |
| Priority date | — |
| Expiry date | Mar 27, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/0825
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A wireless key system and location detection method determine whether a wireless key is located inside or outside a main body. A communication device in the main body transmits a wireless signal using an inner antenna and an outer antenna outside the main body having a different directivity. A wireless key measures direction of movement of the wireless key when the wireless signal is received by one of antennas having different directivities, detects one of the antennas receiving the highest signal level of the wireless signal as a first antenna, selects one of the antennas having the same directivity as the inner antenna as a second antenna according to the measured direction of movement and detected directivity of the antenna, and decides that the wireless key is inside the main body based on the signal levels of the wireless signals received by the first and second antennas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.