Antenna device in automotive keyless entry system
US4873530A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1986 |
| Grant date | Oct 10, 1989 |
| Priority date | — |
| Expiry date | Sep 29, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07C2209/63
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
In a ratio-mediated keyless entry system for an automotive vehicle, two vehicle-mounted antennae, lying in mutually perpendicular planes are used to receive radio signals from a portable, manually operable transmitter. When the transmitter is left in the passenger compartment and then the doors are locked, the system generates an alarm to notify the driver of the fact. On antenna completely encircles the passenger compartment. Encircling the passenger compartment with one of the vehicle-mounted antennae ensures that wherever the transmitter is left in the passenger compartment, its presence will be detected no matter how limited the transmitter's range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.