Smart keyless entry system
A transmitting antenna to transmit a request signal in a vehicle compartment is disposed off the center line of the vehicle compartment in a vehicle width direction. The output strength of the request signal transmitted by the transmitting antenna is switched in such a manner that a receivable output range of the request signal by a portable device reaches one of both doors which is equipped with one of access switches which has been operated. Accordingly, it can be properly recognized whether the portable device is located inside the vehicle compartment or outside the vehicle compartment even if the transmitter to transmit the request signal in the vehicle compartment is disposed off the center line of the vehicle compartment in the vehicle width direction.
1. A smart keyless entry system, comprising:
switches provided at outer faces of a right-side door and a left-side door of a vehicle;
an onboard device operative to transmit a request signal in response to operation of the switches;
a portable device operative to transmit a receipt-acknowledgement signal in response to receiving the request signal;
an onboard control device to be activated by the onboard device in response to receiving the receipt-acknowledgment signal,
wherein said onboard device comprises a determination module for determining whether the switch on the right-side door or the switch on the left-side door is operated and a vehicle-inside transmitter having a transmitting antenna to transmit the request signal in a vehicle compartment, the vehicle-inside transmitter being a switching transmitter having the transmitting antenna disposed at a specified position which is off a center line of the vehicle compartment in a vehicle width direction, and the onboard device is configured to switch an output strength of the request signal transmitted by the switching transmitter based on determination result of said determination module such that a receivable output range of the request signal by said portable device reaches one of the doors which is equipped with the switch which has been determined by the determination module to have been operated in such a manner that in a case where the switch on any one of said doors located near from the switching transmitter is operated, said output strength provides a narrow receivable output range, wherein the request signal does not reach the door equipped with the switch that has not been operated, whereas in a case where the switch on the other door located far from the switching transmitter is operated, said output strength provides the wide receivable output range so as to reach both the right-side door and the left-side door of the vehicle.
2. The smart keyless entry system of claim 1 , wherein said vehicle-inside transmitter comprises a plural transmitters which are disposed at a front portion and a rear portion in the vehicle compartment respectively, and the transmitter at the front portion is said switching transmitter.
3. The smart keyless entry system of claim 1 , wherein said switching transmitter at the front portion is disposed on a vehicle floor below a driver's seat.
4. The smart keyless entry system of claim 1 , wherein said request signal is a signal of LF band, and said receipt-acknowledgement signal is a signal of UHF band.