PROBLEM TO BE SOLVED: To discriminate whether a subject is biological or not by just changing/adding a part of a constitution of a conventional optical fingerprint image input device.SOLUTION: This device is formed by paying attention that a material (gummy) formed by gelatinizing a gelatin aqueous solution has form birefringence, for example, two polarizing plates are added to a conventional total reflection type optical fingerprint image input device, a monochrome image-pickup device is changed into a color image pick-up device, a spatial or temporal fluctuation of light receiving intensity is calculated based on fingerprint information entering the image pick-up device, and when the fluctuation exceeds a prescribed threshold, this device discriminates that the subject is the forged fingerprint formed of gummy and when the fluctuation is a prescribed threshold or less, discriminates that the subject is a biological fingerprint.COPYRIGHT: (C)2007,JPO&INPIT【課題】従来の光学的指紋像入力装置における一部の構成を変更・追加するだけで、被検体が生体か否かの判別をも可能とさせることを目的としている。【解決手段】ゼラチン水溶液をゲル化した素材(グミ)には複屈折性を有することに着目し、例えば従来の全反射法光学方式指紋像入力装置に偏光板2枚追加し、撮像素子をモノクロからカラーのものに変更し、撮像素子に入射された指紋情報に基づき、受光強度の空間的または時間的な変動量を算出し、変動量が所定の閾値を超えた場合には被検体はグミで作られた偽造指紋であると判別し、変動量が所定の閾値以下である場合には被検体は生体の指紋であると判別する。【選択図】図1
