Vehicle automatic door-locking system using identifier signal transmitting portable unit

An automatically controlled door-locking system for automatically locking at least one door of a vehicle, which includes a vehicle-operator's door provided for an operator of the vehicle, said door-locking system comprising:

• a power-operated locking device including a power source, and an actuator operated by said power source for selectively locking and unlocking said at least one door placed in a closed position thereof;
• a symptom detecting device operable to detect a symptom indicating that the operator has an intention of getting off the vehicle;
• a portable unit to be carried by said operator;
• a first communication device operable to communicate with said portable unit while said portable unit is located within a predetermined first area, said first communication device including a first identifier-signal requesting device and a first signal-receiving device, said first identifier-signal requesting device being operable, upon detection of said symptom by said symptom detecting device, to transmit to said portable unit a request signal requesting said portable unit to transmit back to said first signal-receiving device an identifier signal representative of an identifier identifying said portable unit;
• getting-off detecting means for detecting a high probability that the operator of the vehicle has got off the vehicle;
• a fourth communication device operable upon detection of said high probability by said getting-off detecting means and capable of communicating with said portable device while said portable unit is located within a predetermined second area, said fourth communication device including a fourth identifier-signal requesting device for transmitting said request signal, and a fourth signal-receiving device for receiving said identifier signal transmitted from said portable unit;
• and
• a locking-device controller including (a) a first portable-unit detecting device for determining whether said portable unit is located within said predetermined first area of said first communication device, depending upon whether an identifier represented by said identifier signal received by said first signal-receiving device matches the identifier of the vehicle, and (b) a second portable-unit detecting device for determining whether said portable unit is located within said predetermined second area of said fourth communication device, depending upon whether an identifier represented by said identifier signal received by said fourth signal-receiving device matches the identifier of the vehicle, said locking-device controller operating said power-operated locking device to lock said at least one door of the vehicle, on the basis of at least one of output signals of said first and second portable-unit detecting devices.

An automatically controlled door-locking system for automatically locking at least one door of a vehicle, which includes a vehicle-operator's door provided for an operator of the vehicle, said door-locking system comprising:

• a power-operated locking device including a power source and an actuator operated by said power source for selectively locking and unlocking said at least one door placed in a closed position thereof;
• a portable unit to be carried by said operator;
• a communication device including an identifier-signal requesting device and a signal-receiving device, said identifier-signal requesting device being operable to transmit to said portable unit a request signal requesting said portable unit to transmit back to said signal-receiving device an identifier signal representative of an identifier identifying said portable unit, said communication device being capable of communicating with said portable unit in a plurality of different communication areas;
• and
• a locking-device controller including a portable-unit detecting device for determining whether said portable unit is located within each of said plurality of different communication areas, by determining whether said identifier represented by said identifier signal received by said signal-receiving device matches an identifier identifying the vehicle, said locking-device controller operating said power-operated locking device to lock said at least one door of the vehicle, on the basis of results of determinations by said portable-unit detecting device as to whether said portable unit is located within each of at least two areas of said plurality of different communication areas.