| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a keyless entry system which enables avoidance of a change in a distance for locking or unlocking vehicle doors even when the strength of a surrounding electric field changes by a constitution wherein a vehicle-borne machine detects the state of the surrounding electric field and makes a locking or unlocking threshold value small when this state of the electric field is faulty (bad) and which enables consequently elimination of a feeling of disorder of a driver and also execution of a locking or unlocking operation at a correct distance for ensuring both crime preventing properties and convenience, in regard to a keyless entry system equipped at least with a unidirectional communication function. SOLUTION: In a keyless entry system free of a switch operation wherein a vehicle-borne machine 1 locks or unlocks vehicle doors according to the strength of a reception electric field of a transmission signal from a portable machine 2, the vehicle-borne machine 1 detects the state of a surrounding electric field and also makes a locking or unlocking threshold value small when the detected state of the electric field is faulty.</p> |
