| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electronic key system of a vehicle, which is effective for the prevention of a forcible entry of a third person into a vehicle interior. <P>SOLUTION: In this electronic key system of the vehicle, a distance measurement signal Scd is given and received between an in-vehicle device 10 and a portable machine 20; it is determined through the giving and receiving of the signal that the portable machine 20 is positioned in a communicable area A; a request signal Srs and a response signal Sas are given and received; the authentication of the portable machine 20 is established through giving and receiving of the signals; and a vehicle door is unlocked on the basis of the determination and the establishment of the authentication. In this case, after a re-request signal Srr is transmitted after the transmission of the request signal Srs from the in-vehicle device 10, the portable machine 20 specifies a mode of a reply of the portable machine 20 to the re-request signal Srr. The vehicle door is unlocked under additional condition that the portable machine 20 replies to the re-request signal Srr on the basis of the specified reply mode. <P>COPYRIGHT: (C)2011,JPO&INPIT |
