Patent ID: 8285455

Claim:
A seat belt warning device comprising: a seat belt restraining a passenger seated on a seat for a vehicle when the seat belt is in an engagement state and releasing the passenger when the seat belt is in a disengagement state; a load detecting device including two load sensors that are provided at a rear portion of the seat and that are arranged away from each other in a width direction of the vehicle, the load detecting device detecting a load applied to a seating surface of the seat, the seat including a seatback at the rear portion of the seat; a warning member warning the passenger to fasten the seat belt in response to the load detected by the load detecting device; and a controlling portion determining one of an unoccupied-seat recognition mode where an unoccupied-seat state is recognized, a passenger seating recognition mode where it is determined that the passenger is seated on the seat and the warning member is allowed to operate, and a luggage recognition mode where it is determined that luggage is placed on the seat and the warning member is prohibited to operate, the controlling portion performing a first transition process in which the unoccupied-seat recognition mode is shifted to the luggage recognition mode under a condition where the load detecting device detects the load greater than a first load and smaller than a second load and in which the luggage recognition mode is shifted to the unoccupied-seat recognition mode under a condition where the load detecting device detects the load smaller than a third load for a predetermined first time period, the controlling portion performing a second transition process in which the unoccupied-seat recognition mode is shifted to the passenger seating recognition mode under a condition where the load detecting device detects the load equal to or greater than the second load and in which the passenger seating recognition mode is shifted to the unoccupied-seat recognition mode under a condition where the load detecting device detects the load smaller than the third load for the predetermined first time period, wherein the controlling portion prevents a shift from the luggage recognition mode to the passenger seating recognition mode after the luggage recognition mode is determined, and prevents a shift from the passenger seating recognition mode to the luggage recognition mode after the passenger seating recognition mode is determined.