PROBLEM TO BE SOLVED: To provide an arousal reduction detector which can enhance estimation accuracy of an arousal reduction level.SOLUTION: The arousal reduction detector comprises: first arousal degree calculating means for calculating first arousal degree of a driver based on at least one of vehicle information and information indicating a driving state of the driver second arousal degree calculating means for calculating second arousal degree, differently from the first arousal degree calculating means, based on a subsidiary action by the driver in an initial state of arousal reduction and arousal reduction level estimating means for estimating the arousal reduction level of the driver by using the first arousal degree and the second arousal degree.COPYRIGHT: (C)2012,JPO&INPIT【課題】覚醒低下レベルの推定精度を高めることができる覚醒低下検出装置を提供する。【解決手段】車両情報又は運転手の運転状態を示す情報の少なくともいずれか一方の情報に基づいて、運転手の第1の覚醒度を演算する第1の覚醒度演算手段と、第1の覚醒度検出手段と異なり、覚醒度低下の初期状態における運転手の副次的動作に基づいて、第2の覚醒度を演算する第2の覚醒度演算手段と、第1の覚醒度と前記第2の覚醒度とを用いて、運転手の覚醒低下レベルを推定する覚醒低下レベル推定手段とを備える。【選択図】 図2
