1. A blood vessels pattern imaging device, comprising: a plurality of light sources for radiating light, the plurality of light sources being arranged in a grid-shaped manner; a surface region on which a hand of a human is positioned; an imaging unit for imaging a plurality of fingers of the hand upon the hand being positioned on the surface region; and a light amount adjusting unit for selecting one or more light sources for radiation from the plurality of light sources corresponding to each of the plurality of fingers, and adjusting an amount of light radiated from the one or more light sources in accordance with each of the plurality of fingers.