Patent attributes
There are included: a frequency distribution creating unit for referring to the face information detected by the face information detecting unit, and when a preset change occurs in the driver's face, creating a frequency distribution of face information in a preset time section from the face information detected by a face information detecting unit; a mode value calculating unit for calculating a mode value of the face information from the frequency distribution created; and a reference value calculating unit for calculating a reference value indicating a steady state of the driver from the mode value of the face information.