Keyless entry system
View Patent ↗A keyless entry system includes a portable transmitter that transmits a lock signal and an unlock signal, each of which contains a unique identification code, for a predetermined period, and an operation unit that locks and unlocks doors of a vehicle in response to the lock signal and the unlock signal from the portable transmitter. The operation unit includes a receiver that outputs a lock command signal or an unlock command signal having a predetermined time length, and a controller that drives an actuator to lock or unlock the doors of the vehicle in response to the lock command signal or the unlock command signal from the receiver. The time length of the unlock command signal from the receiver is shorter than the time length of the unlock signal from the portable transmitter.
1. A keyless entry system comprising:
a portable transmitter that transmits respectively a lock signal and an unlock signal for a predetermined length of time, each of the lock signal and the unlock signal containing an identification code; and
an operation unit that locks and unlocks doors of a vehicle in response to the lock signal and the unlock signal transmitted from the portable transmitter,
wherein the operation unit includes:
a receiver that receives the lock signal for executing locking operation once or the unlock signal for executing unlocking operation once transmitted from the portable transmitter, and that outputs a lock command signal or an unlock command signal having a predetermined time length when the received lock signal or the unlock signal has the predetermined length of time, and the identification code is identified; and
a controller that drives actuators to lock or unlock the doors of the vehicle in response to the lock command signal or the unlock command signal output from the receiver, and
wherein the time length of the unlock command signal is shorter than the time length of the unlock signal for executing unlocking operation once transmitted from the portable transmitter.
2. The keyless entry system according to claim 1 , wherein the time length of the unlock command signal is shorter than the time length of the lock command signal.
3. The keyless entry system according to claim 2 , wherein the controller drives the actuators to lock all the doors when the lock command signal is input from the receiver, drives only the actuator corresponding to a door beside a driver's seat to unlock the door beside the driver's seat when the unlock command signal is first input, and drives the actuators corresponding to the doors other than the door beside the driver's seat to unlock the doors other than the door beside the driver's seat when the unlock command signal is input again within a predetermined time.
4. The keyless entry system according to claim 2 , wherein, when the controller receives the unlock command signal from the receiver, the controller drives the actuators for the same period as a period in which the actuators are driven when the lock command signal is input.
5. The keyless entry system according to claim 2 , wherein the controller drives the actuators for a period corresponding to the time length of the lock command signal or the unlock command signal received from the receiver.
6. The keyless entry system according to claim 1 , wherein the time length of the unlock command signal is 400 msec or less.
7. The keyless entry system according to claim 1 , wherein the receiver outputs the lock command signal or the unlock command signal when the identification code of the lock signal or the unlock signal is identified.
8. The keyless entry system according to claim 1 , wherein the unlock command signal and the signal indicating the identification code of the portable transmitter are subjected to amplitude modulation by a transmitting circuit.
9. The keyless entry system according to claim 1 , wherein the controller determines that the lock or unlock command signal is an authorized signal when the input lock or unlock command signal is a signal having the predetermined time length.
10. The keyless entry system according to claim 9 , wherein the lock or unlock command signal is a rectangular wave signal.
11. The keyless entry system according to claim 1 , wherein the receiver receives the lock or unlock signal having the predetermined length of time and the identification code is identified, the receiver outputs the lock or unlock command signal immediately irrespective of whether the lock or unlock command signal is currently being outputted or not.
12. A keyless entry system comprising:
a portable transmitter that transmits a lock signal and an unlock signal, each of the lock signal and the unlock signal having a predetermined time length and containing an identification code; and
an operation unit that locks and unlocks doors of a vehicle in response to the lock signal and the unlock signal transmitted from the portable transmitter,
wherein the operation unit includes:
a receiver that receives the lock signal or the unlock signal transmitted from the portable transmitter, and that outputs a lock command signal or an unlock command signal having a predetermined time length when the received lock signal or the unlock signal has the predetermined length of time, and the identification code is identified; and
a controller that drives actuators to lock or unlock the doors of the vehicle in response to the lock command signal or the unlock command signal output from the receiver,
wherein the time length of the unlock command signal is shorter than the time length of the unlock signal, and
wherein the time length of the unlock command signal is shorter than the time length of the lock command signal.