Patent ID: 8244436

Claim:
An occupant detection apparatus for a vehicle, comprising: a buckle switch configured to detect whether a seatbelt of the vehicle is fastened or unfastened; a seat position sensor configured to detect position of a seat of the vehicle, wherein the seat is selectively movable frontward and rearward; and an electronic control unit including: an energization control part including: a first active element that is selectively switchable into an on state and an off state to control energization of the buckle switch so that the buckle switch is energized when the first active element is in the on state, and the buckle switch is unenergized when the first active element is in the off state; and a second active element that is selectively switchable into an on state and an off state to control energization of the seat position sensor so that the seat position sensor is energized when the second active element is in the on state, and the seat position sensor is unenergized when the second active element is in the off state; and an computation control part that is configured to perform on-off control individually on the first active element and the second active element by (i) applying a first voltage to the first active element to and (ii) applying a second voltage to the second active element, in such manner that: the computation control part causes the first active element to be in the on state for a predetermined period; and at a time of an end of the predetermined period, the computation control part switches the first active element into the off state and switches the second active element into the on state.