PROBLEM TO BE SOLVED: To provide an ethyl alcohol detector which is constituted so as to detect ethyl alcohol in blood from the infrared rays radiated from a driver to be utilized in the prevention of driving under the influence of liquor.SOLUTION: An imaging control part 38 is constituted so as to respectively take a first subject image of a first wavelength band containing the absorbing wavelength &lambda1 of ethyl alcohol from the infrared radiated light of a subject 18, a second subject image containing a wavelength &lambda2 low in the absorptivity by ethyl alcohol in the vicinity of the first wavelength band and a third subject image of a third wavelength band containing another absorbing wavelength &lambda3 of a disturbance substance having an absorbing wavelength in the same first wavelength band as ethyl alcohol by replacing a filter to store them in a memory. An ethyl alcohol detection part 40 calculates an ethyl alcohol-containing degree on the basis of the first and second subject images, and a disturbance substance detection part 42 calculates a disturbance substance detection value on the basis of the second and third subject images. A judge part 44 judges the detection or non-detection of ethyl alcohol on the basis of the ethyl alcohol-containing degree and the disturbance substance detection value.COPYRIGHT: (C)2009,JPO&INPIT【課題】運転者の放射する赤外線から血中のエチルアルコールを検知して酒気帯び防止などに利用可能とする。【解決手段】撮像制御部38は、フィルタ切替えにより被写体18の赤外線放射光からのエチルアルコールの吸収波長λ1を含む第1波長帯域の第1被写体画像、第1波長帯域の近傍のエチルアルコールによる吸収率の小さな波長λ2を含む第2被写体画像、エチルアルコールと同じ第1波長帯域に吸収波長を持つ外乱物質の他の吸収波長λ3を含む第3波長帯域の第3被写体画像の各々を撮像してメモリに格納する。エチルアルコール検出部40は第1被写体画像と第2被写体画像に基づいてエチルアルコール含有度を算出し、外乱物質検出部42は第2被写体画像と第3被写体画像に基づいて外乱物質検出値を算出する。判定部44はエチルアルコール含有度と外乱物資検出値に基づいてエチルアルコールの検出又は非検出を判定する。【選択図】図1
