| 摘要 |
An electronic key device includes a portable device (3)capable of being carried by a user, and a vehicle-mounted device (2) configured to perform mutual communication with the portable device (3). The vehicle-mounted device (2) includes a plurality of antennas (ANT1, ANT2, ANT3) that is provided in different positions of a vehicle and is configured to transmit radio waves every predetermined time. A response signal based on the reception strength of the radio waves transmitted from the plurality of antennas is transmitted from the portable device (3) to the vehicle-mounted device (2). The vehicle-mounted device (2) determines that a moving direction of the portable device (3) heads for any one of the antennas based on the response signal, and when it is determined that a distance between the vehicle (1) and the portable device (3) is equal to or less than a predetermined threshold, control is performed such that a door (1a, 1b) becomes unlocked. |
