| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a keyless entry device that accurately measures a position of a portable device based on a received signal intensity even if a power supply output of a vehicle fluctuates. <P>SOLUTION: A vehicle-side device 2 includes a driving circuit 17 provided in a vehicle-side transmission section 11 driving to supply electric power from a power supply section 4 of a vehicle 1 to transmission antennas 15 and transmit a signal from a vehicle-side control section 12, and an output measurement circuit 18 for measuring an output level of a signal the driving circuit 17 causes the transmission antennas 15 to transmit. The vehicle-side control section 12 calculates an actual distance between each transmission antenna 15 and a portable device 3 from distance data between each transmission antenna 15 and the portable device 3 based on intensity data detected by a portable device control section 22 and data of output level of a signal in the driving circuit 17, measured by the output measurement circuit 18. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
