Patent ID: 11908232
Assignee: NEC CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G  A | IPC A  G

Claim 3:
4. An authentication method using an apparatus, the apparatus including:
a prism arranged so that a bottom surface, out of two parallel surfaces of the prism, is a placing surface side for a finger;
a first imaging sensor arranged below a top surface parallel to the bottom surface, the first imaging sensor configured to image a first image of the finger transmitted through the top surface;
a second imaging sensor configured to image a second image of the finger transmitted through a first set of side surfaces, out of two sets of side surfaces that face each other;
an inclined surface in contact the prism;
a light shield at the inclined surface;
a first infrared light source arranged at the light shield for irradiating first infrared ray light to a root portion of the finger; and
a second infrared light source arranged opposite to the first infrared light source with respect to the prism for radiating second infrared ray light to a portion of the finger that is not in contact with the placing surface of the finger, wherein
the inclined surface is inclined toward the bottom surface of the prism so that a height of the inclined surface decreases as a distance from the prism becomes larger,
the first infrared light source is arranged at the light shield so that the first infrared ray light from the first infrared light source does not enter the prism,
the authentication method comprising:
receiving, by the second image sensor, the first infrared ray light and the second infrared ray light transmitted from the first infrared light source and the second infrared light source through the first set of side surfaces to capture a blood vessel image of the finger, and
determining whether or not the finger is a living body based on the blood vessel image.