| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide, even when there is an external noise signal, a keyless entry system capable of receiving an authentication signal transmitted from a portable transmitter/receiver within an area in the direction perpendicular to a door of a driver's side where a user most likely brings the portable transmitter/receiver closer, so as to reliably lock/unlock the vehicle. <P>SOLUTION: The portable transmitter/receiver includes also an ID signal transmitting part transmitting a specific ID signal. The on-vehicle device includes a main aerial receiving a signal transmitted from outside, a sub-aerial provided near a vehicle door with a directivity more perpendicular to the vehicle-door side than the main aerial and receiving the signal transmitted from outside, and a receiving-aerial setting part which sets the main aerial as a receiving aerial at normal times while setting the sub-aerial as a receiving aerial when an authentication-disabled state detecting part detects that authentication by the ID-signal is in a disabled condition. <P>COPYRIGHT: (C)2009,JPO&INPIT |
