Patent ID: 7616295

Claim:
A biometric identification apparatus comprising: a finger placement portion in which a finger is placed; a first, a second and a third light source having different wavelengths from one another for emitting light to the finger; and a receiver for detecting the light passing through the finger; wherein the first and the second light source are disposed so that the optical axis of the first light source and that of the second light source form lines perpendicular to the bottom surface of the finger placement portion; wherein the third light source is disposed so that the optical axis of the third light source is parallel to the bottom surface of the finger placement portion and is perpendicular to the optical axis of the first light source and that of the second light source; wherein a receiving surface of the receiver is disposed parallel to the bottom surface of the finger placement portion; and wherein a transmittance; that is, a light intensity ratio of the light emitted from each of the first, the second and the third light source to the light detected with the receiver, is obtained the transmittance is compared with respective previously-set thresholds of transmittance, to detect whether or not the finger is a living body, and a detection result is displayed.