Door lock/unlock system

1. A door lock/unlock system for a vehicle, comprising:

a door lock state detector detecting whether a door of the vehicle is put in a lock state;

a door open state detector detecting whether the door is open;

a door lock mechanism through which the door is locked and unlocked; and

a controller connected to the door lock state detector, the door open state detector and the lock mechanism, the controller being arranged,

to compare a first lock/unlock state detected by the door lock state detector during the door open state with a second lock/unlock state detected by the door lock state detector at a moment when an open/close state is changed from an open state to a closed state,

to maintain the state of the door lock mechanism when the first lock/unlock state equals to the second lock/unlock state, and

to set the state of the door lock mechanism at the first lock/unlock state when the first lock/unlock state does not equal to the second lock/unlock state.

2. The door lock/unlock system as claimed in claim 1 , wherein the controller is further arranged to count a time period from a moment that the open/close state is changed from the open state to the closed state and to compare the first lock/unlock state and the second lock/unlock state when the counted time period is smaller than the predetermined time period.

3. The door lock/unlock system as claimed in claim 1 , wherein the door lock mechanism comprises a door lock actuator which is connected to the controller and though which the door lock mechanism changes the lock/unlock state of the door.

4. The door lock/unlock system as claimed in claim 1 , wherein the door lock state detector, the door open state detector and the door lock mechanism are attached to each of the doors of the vehicle.

5. The door lock/unlock system as claimed in claim 1 , wherein the controller is further arranged to update a lock/unlock state detected by the door lock state detector which is stored in a memory of the controller as the first lock/unlock state, when the door is open.

6. The door lock/unlock system as claimed in claim 1 , further comprising an overlay switch for setting the lock/unlock state with a priority to the determination based on the door lock state detector.

7. The door lock/unlock system as claimed in claim 6 , wherein the overlay switch includes a concentrated door lock/unlock switch through which a driver of the vehicle concentratedly controls the door lock/unlock state of all of the doors of the vehicle.

8. The door lock/unlock system as claimed in claim 1 , further comprising a door locking knob through which a vehicle occupant in a passenger compartment of the vehicle is capable of locking the door.

9. A method for controlling a lock/unlock state of a door of a vehicle, the method comprising:

detecting whether the door is put in a lock state;

detecting whether the door is open;

comparing a first lock/unlock state detected during the door open state with a second lock/unlock state detected at a moment when an open/close state is changed from an open state to a closed state;

maintaining the state of a door lock mechanism for locking and unlocking the door when the first lock/unlock state equals to the second lock/unlock state; and

setting the state of the door lock mechanism at the first lock/unlock state when the first lock/unlock state does not equal to the second lock/unlock state.

10. A door lock/unlock system for a vehicle, comprising:

lock/unlock operation means for locking and unlocking a door;

lock/unlock mechanism interconnected with the lock/unlock operation means, the lock/unlock mechanism locking and unlocking the door according to an operation of the lock/unlock operation means;

door open state detecting means for detecting an open/close state of the door;

door lock state detecting means for detecting a lock/unlock state of the door; and

door lock/unlock controlling means for controlling an operation of the lock/unlock mechanism, the door lock/unlock controlling means comparing the lock/unlock state detected by the door lock state detecting means during the door open state with the lock/unlock state detected by the door lock state detecting means at a moment that the door open state is changed from an open state to a close state, maintaining the state of the door actuator when the lock/unlock state during the door open state equal to the lock/unlock state at the moment that the open/close state is changed from the open state to the close state, and setting the lock/unlock state of the door lock mechanism at the lock/unlock state during the door open state when the lock/unlock state during the door open state does not equal to the lock/unlock state at the moment that the open/close state is changed from the open state to the close state.