Electronic key system operable with charge capacitor power
US6965295B2 · kind B2 · utility
38Cited by
5References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 7, 2003 |
| Grant date | Nov 15, 2005 |
| Priority date | — |
| Expiry date | Jan 26, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07C2209/65
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An electronic key system has a portable electronic key and a transmitter provided in a vehicle. The key and the transmitter have respective LC resonance circuits including antenna coils that can be electromagnetically coupled. The portable device has a charge capacitor and a diode. The capacitor is charged with a voltage induced by the coil when the LC resonance circuit resonates. The electronic key is enabled to communicate with the transmitter with the charged voltage of the charge capacitor when a built-in battery runs down.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.