Patent ID: 7639125
Filing Date: 2009-12-29
Classification: B60N,B60R

Abstract:
1. Seat belt warning system comprising a sensing system associated to a vehicle seat for sensing a seat belt related status with respect to said vehicle seat and a control unit communicating with said sensing system for generating a warning signal depending on the seat belt related status determined by said sensing system, wherein said sensing system comprises a seat occupancy detector for determining a seat occupancy status of a vehicle seat, a seat belt fastening detector for determining a seat belt usage condition, a first surface acoustic wave device including at least one surface acoustic wave resonator and an antenna, said first surface acoustic wave device being connected to at least one of said seat occupancy sensor and said seat belt fastening device in such a way that a resonance frequency of the surface acoustic wave device is modulated depending on the output signals of the at least one of said seat occupancy sensor and said seat belt fastening device, whichever the surface acoustic wave device is connected to; and wherein said control unit comprises an RF antenna for remotely communicating with said surface acoustic wave device, and wherein said seat occupancy sensor and said seat belt fastening detector remotely communicate so as to provide a combined occupancy and seat belt signal and wherein said combined occupancy and seat belt signal is transmitted to said control unit via said first surface acoustic wave device.