Compact biometric authentication device and associated methodology of imaging and detecting living-tissue patterns

A device, comprising:

• a light emitter that emits near-infrared source light at a hemoglobin absorbance wavelength;
• an imaging circuit that captures images of a blood vessel of a user based on scattered light which is a portion of said source light that has penetrated an epidermal layer and is scattered by tissue in a deep layer;
• a discriminating circuit that discriminates whether tissue of the user is living-tissue or non-living-tissue by discriminating changes in an absorbance of the blood vessel between the images according to a heartbeat of the user;
• and
• a detecting circuit that detects a biometric pattern based on the tissue when the discriminating circuit discriminates that the tissue is living-tissue,
• wherein the imaging circuit captures a first image of the blood vessel and a second image of the blood vessel, and
• wherein the discriminating circuit is configured to:
• discriminate a difference between the absorbance of the blood vessel in the first image and the absorbance of the blood vessel in the second image,
• determine that the blood vessel is a part of living-tissue when the difference is above a predetermined threshold, and
• determine that the blood vessel is a part of non-living-tissue when the difference is below the predetermined threshold.