PROBLEM TO BE SOLVED: To provide a drowsiness detection device for detecting drowsiness based on an opening/closing movement of a person's eyelids capable of detecting an occurrence of drowsiness of a subject more accurately than ever before even in the subject who intends not to blink when the drowsiness increases.SOLUTION: A drowsiness detection device includes means for detecting an opening/closing state of eyelids of a subject, means for sequentially detecting a time interval of transition between an open state and a closed state of eyelids, means for calculating a feature amount of eyelid opening/closing from data on the time interval of transition between an open state and a closed state of eyelids, and drowsiness determination means for determining that the subject is feeling drowsiness when the feature amount of eyelid opening/closing is below a first threshold, and above a second threshold higher than the first threshold.SELECTED DRAWING: Figure 2【課題】人の瞼の開閉運動に基づいて眠気を検知する装置に於いて、眠気が増加した際に意図的に瞬きをしないようにする被検者の場合にも、被検者の眠気の発生を従前よりも精度よく検知できる装置を提供する。【解決手段】被検者の瞼の開閉状態を検出する手段と、瞼の開状態と閉状態との間の遷移の時間間隔を逐次的に検出する手段と、瞼の開状態と閉状態との間の遷移の時間間隔のデータから瞼開閉特徴量を算出する手段と、瞼開閉特徴量が第一の閾値を下回ったとき、及び、第一の閾値よりも高い第二の閾値を上回ったときに、被検者が眠気を感じていると判定する眠気判定手段とを含む。【選択図】図２
