Abstract: If a portable device receives a request signal from a control device that requires a response from the portable device, a first response signal is transmitted from the portable device during a common period defined in all portable devices. Thus, in a case where there is no portable device which enables wireless communication with the control device, a value of received signal strength indication of a wireless signal which is received from the portable device by the control device is very small and becomes smaller than the threshold value during a period in the common period. In this case, the control device suspends reception processing of causing a signal to be transmitted from the plurality of portable devices subsequently to the first response signal.

Abstract: An electronic key device includes a portable device capable of being carried by a user, and a vehicle-mounted device configured to perform mutual communication with the portable device to perform predetermined control. The vehicle-mounted device includes a plurality of antennas 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 to the vehicle-mounted device. The vehicle-mounted device determines that a moving direction of the portable device heads for any one of the antennas based on the response signal, and when it is determined that a distance between the vehicle and the portable device is equal to or less than a predetermined threshold, control is performed such that a door becomes unlocked.

Abstract: If a portable device receives a request signal from a control device that requires a response from the portable device, a first response signal is transmitted from the portable device during a common period defined in all portable devices. Thus, in a case where there is no portable device which enables wireless communication with the control device, a value of received signal strength indication of a wireless signal which is received from the portable device by the control device is very small and becomes smaller than the threshold value during a period in the common period. In this case, the control device suspends reception processing of causing a signal to be transmitted from the plurality of portable devices subsequently to the first response signal.

Abstract: An electronic key device includes a portable device capable of being carried by a user, and a vehicle-mounted device configured to perform mutual communication with the portable device to perform predetermined control. The vehicle-mounted device includes a plurality of antennas 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 to the vehicle-mounted device. The vehicle-mounted device determines that a moving direction of the portable device heads for any one of the antennas based on the response signal, and when it is determined that a distance between the vehicle and the portable device is equal to or less than a predetermined threshold, control is performed such that a door becomes unlocked.

Abstract: A keyless entry device of a vehicle includes: a transmission unit installed in the vehicle that transmits a search signal to a search range including an area inside the vehicle and a vicinity area outside the vehicle; a reply unit installed in a portable device carried by a user that transmits a reply signal when receiving the search signal at several locations within the search range; a determination unit that individually determines whether the portable device is present in the area inside the vehicle and the vicinity area outside the vehicle within the search range on the basis of the reply signal transmitted from the portable device; and a control unit that controls locking or unlocking of a door of the vehicle on the basis of the determination result of the determination unit.

Abstract: A keyless entry device of a vehicle includes: a transmission unit installed in the vehicle that transmits a search signal to a search range including an area inside the vehicle and a vicinity area outside the vehicle; a reply unit installed in a portable device carried by a user that transmits a reply signal when receiving the search signal at several locations within the search range; a determination unit that individually determines whether the portable device is present in the area inside the vehicle and the vicinity area outside the vehicle within the search range on the basis of the reply signal transmitted from the portable device; and a control unit that controls locking or unlocking of a door of the vehicle on the basis of the determination result of the determination unit.

Abstract: There is provided a passive keyless entry system transmitting a request signal at a predetermined time period from a vehicle-side device, transmitting an answer signal when a portable device has received the request signal, and comprising a control unit that performs predetermined control if the answer signal is received or not received by the vehicle-side device. The portable device includes a portable device control unit that detects the intensity of the request signal transmitted from the vehicle-side device, and is adapted such that, if the intensity of a request signal has changed by a predetermined value or more compared with the intensity of a previously received request signal, a normal answer signal is transmitted as the answer signal, and that, if the intensity of the request signal has changed by less than a predetermined value, a simple answer signal that is shorter than the normal answer signal is transmitted as the answer signal.