Patent ID: 8467931

Claim:
A seat occupancy determining apparatus comprising: only one left load detecting portion provided at a left side portion of a seat portion of a vehicle seat and detecting a load applied to the left portion of the seat portion; only one right load detecting portion provided at a right side portion of the seat portion and detecting a load applied to the right side portion of the seat portion; a vehicle operation detecting portion for detecting an operation of a predetermined component of a vehicle; and a seat occupancy determining portion determining a seat occupancy state of the vehicle seat on the basis of signals outputted from the vehicle operation detecting portion, the only one left load detecting portion and the only one right load detecting portion, the seat occupancy determining portion calculating a load difference value by subtracting the load detected by one of the right and left load detecting portion from the load detected by the other one of the right and left load detecting portion and determining that a child seat is placed on the vehicle seat and the vehicle seat is in a child seat fastened state where the child seat is fastened to the vehicle seat by means of a seat belt apparatus in a case where an increase of the load difference value from a minus reference value, which is set as a negative value, by a predetermined value occurs or in a case where a decrease of the load difference value from a plus reference value, which is set as a positive value, by a predetermined value occurs after the predetermined component of the vehicle is operated.