an identification apparatus keeps the conditions for imaging uniform among successive identifications , and requires a user to perform only a series of simple maneuvers . the apparatus comprises a guide member , a light source , and an imaging unit . the guide member includes a pattern or structure for a user to position his / her finger thereon or to approach his / her specific finger region thereto . a contact member is located in the guide member where a fingertip is positioned . an optical opening is formed at a position coincident with where a finger to be imaged should be placed . the light source radiates near - infrared light through the portion of the finger to be imaged . the imaging means acquires an image of the finger , and the apparatus compares the image to previously registered images . the apparatus may also include dual light sources power saving functionality , and means for limiting the interference of external light sources .