Abstract: Predetermined multiple points of the front passenger seat and its periphery are irradiated with spot beams, caught with a camera, and distances are measured based on the irradiation position of the spot beams. Conversely, the characteristics for each status of use of the seat such as the shapes of the contour of the seat or the contour of a child seat are detected from the picture information caught with the camera. The status of use of the seat is decided based the characteristics for each status of use and the distance information that was previously measured. Based on this decision, the operation of a passive safety device such as an air bag device is controlled.

Abstract: A seated-state detection sensor is disposed in a seat portion of a seat cushion of a passenger seat. The seated-state detection sensor is divided into three parts, that is, a first seated-state detection sensor, a second seated-state detection sensor and a third seated-state detection sensor, which are arranged in this order from the rear side of the vehicle. The first seated-state detection sensor and the second seated-state detection sensor are designed to determine whether or not there is a passenger seated. The second seated-state detection sensor and the third seated-state detection sensor are designed to detect forward displacement of the passenger.

Abstract: An apparatus which can accurately detect a state in a passenger compartment is provided. On the ceiling of a passenger compartment above the passenger seat, nine LEDs and three photodetectors are aimed downward, and infrared rays emitted from the LEDs are reflected by an object to be sensed and the reflected light beams are received by the photodetectors. A signal at a level corresponding to the distance to the object to be sensed is outputted from the photodetectors. A controller obtains a change with time in output of the photodetectors (i.e., motion speed from a differential value of the sensed distance, a displacement amount total from an integral value of the sensed distance, and a motion frequency), senses movement of the object to be sensed based thereon, determines whether the object to be sensed is a human, an animal, or other, and determines the kind of object.