PROBLEM TO BE SOLVED: To photograph a biological image obtained by excluding a difference in an individual person as much as possible even though there is a difference in an absorption coefficient of infrared ray due to a finger size, the size and the density of a vein, or the like.SOLUTION: In this biological authentication apparatus comprising an illuminating device for emitting infrared ray, a photographing device for photographing a biological image, and a control device for executing a person himself/herself authentication with the photographed biological image, the illuminating device includes a plurality of illuminating means that correspond to division areas obtained by dividing a photographing range of the photographing device into a plurality of sections, and the control device includes a means for determining average brightness of the biological image of the entire division areas photographed by the photographing device after setting the amounts of output light of the plurality of illuminating means to an initial value, for detecting an adjustment value of the amounts of output light of the illuminating means, wherein a difference between the maximum value and the minimum value of the average brightness of each division area becomes the largest when the average brightness is within a preset threshold, and controlling so as to photograph a biological image for authentication by the photographing device in a state of the amount of the output light at the adjustment value.COPYRIGHT: (C)2011,JPO&INPIT【課題】 指太さ、静脈の太さや密度などでの赤外線の吸収率の差などがあっても個々人の差を極力排除した生体画像を撮影すること。【解決手段】 赤外光を照射する照明装置と、生体画像を撮影する撮影装置と、撮影した生体画像によって本人認証を実施する制御装置とから構成された生体認証装置であって、前記照明装置が、前記撮影装置の撮影範囲を複数区画に分割した分割エリアに対応した複数の照明手段を備え、前記制御装置が、前記複数の照明手段の出力光量を初期値に設定した後、前記撮影装置で撮影した分割エリア全体の生体画像の平均輝度を求め、その平均輝度が予め設定された閾値以内になったならば各分割エリアの平均輝度の最大値、最小値の差が最も大きくなる前記照明手段の出力光量の調整値を検出し、この調整値での出力光量の状態で前記撮影装置により認証用の生体画像を撮影するように制御する手段を備える。【選択図】 図3
