PROBLEM TO BE SOLVED: To sharpen an image to be acquired, reduce the size of an apparatus, and reduce the cost of the apparatus.SOLUTION: In the image reading apparatus 1 including a diffusion plate 5 on which a finger 6 is mounted and which diffuses light incident from the rear surface thereof, a light source 11 which irradiates the finger 6 mounted on the diffusion plate 5 from the rear surface side of the diffusion plate 5 with light at a predetermined irradiation angle, a mirror 13 on which reflected light of the light from the light source 11 by the finger 6 mounted on the diffusion plate 5 is incident, a CCD 12 which receives the light reflected by the mirror 13, thereby photographs the finger 6 mounted on the diffusion plate 5 from the rear surface side of the diffusion plate 5 in a main scanning direction, and outputs an image signal, and a motor 25 for moving a reading unit 3 including at least the light source 11, the mirror 13 and the CCD 12 in a sub scanning direction, the diffusion plate 5 has a diffusion surface which serves as a surface on which the finger 6 is mounted, and a non-diffusion surface which serves as a surface on which light from the light source 11 is incident.COPYRIGHT: (C)2012,JPO&INPIT【課題】取得する画像を鮮鋭化させるとともに、装置を小型化し、低価格化を図る。【解決手段】画像読取装置1は、表面に指6が載置されるとともに、裏面から入射した光を拡散させる拡散板5と、拡散板5の裏面側から所定の照射角度で、拡散板5上に載置された指6に対して光を照射する光源11と、拡散板5上に載置された指6による光源11からの光の反射光が入射されるミラー13と、ミラー13で反射された光を受光することにより、拡散板上に載置された指6を拡散板5の裏面側から主走査方向に撮影し、画像信号を出力するCCD12と、光源11、ミラー13及びCCD12を少なくとも含む読取ユニット3を副走査方向に移動させるモータ25とを備える。拡散板5は、指6が載置される面を拡散面とし、光源11からの光が入射される面を非拡散面とする。【選択図】図2
