Method of detecting biological pattern, biological pattern detector, method of biological certificate and biological certificate apparatus

Abstract

The present invention enables permanent biometric authentication without the risk of forgery or the like. The present invention enables living-tissue discrimination as well as biometric authentication. The roughness distribution pattern of deep-layer tissue of the skin covered with epidermal tissue is detected, thereby extracting a unique pattern of the living tissue. Then, biometric authentication is performed based upon the detected pattern. The roughness distribution pattern of the deep-layer tissue of the skin is optically detected using difference in optical properties between the epidermal tissue and the deep-layer tissue of the skin. In this case, long-wavelength light, e.g., near-infrared light is used as illumination light cast onto the skin tissue. A fork structure of a subcutaneous blood vessel is used as the portion which is to be detected, for example. The portion which is to be detected is determined based upon the structure of the fork structure. In this case, the living-tissue discrimination may be made using the subcutaneous blood vessel.

Description

TECHNICAL FIELD [0001] The present invention relates to a new biometric pattern detecting method and biometric pattern detecting device for acquiring the pattern of a deep skin layer such as dermis or the like, and particularly to a biometric authentication method and a biometric authentication device. BACKGROUND ART [0002] Fingerprints, palm patterns, or the like, are widely used for person authentication. These patterns are skin ridge patterns wherein a part of the epidermal tissue is embedded in the roughness structure of the dermis, and accordingly, the patterns can be directly observed from the outside. That is to say, the aforementioned pattern essentially corresponds to the deep layer structure of the skin such as dermis or the like. The skin of the portion such as a palm, a sole, or the like, has a special structure wherein the epidermal structure corresponds to the structure of the dermis beneath the epidermal tissue, unlike the skin of other portions, leading to the physio...

AI Technical Summary

Benefits of technology

[0013] Specifically, first, polarized light is cast onto the tissue, as well as detecting the reflected light through a polarizing filter with the polarizing plane orthogonal to that of the aforementioned polarized light, thereby detecting the aforementioned roughness distribution pattern. In this case, the polarized light is cast on the surface of the tissue, and the reflected light is filtered with the polarizing filter with the polarizing plane orthogonal to the aforementioned polarized light, and accordingly, only the depolarized light due to scattering in the living tissue, such as back-scattered light, light split due to birefringence, and so forth, is detected, thereby extracting the pattern of the tissue having the nature which causes scattering of light, such as a dermal layer beneath epidermis and so forth. In particular, an arrangement may be made wherein long-wavelength light such as near-infrared light and so forth, which has the nature that the light readily passes through the epidermal tissue, and is readily scattered in dermal tissue, is employed as the aforementioned polarized light, thereby reducing adverse effects...

Problems solved by technology

As a result, it has become clear that discrimination can be made between epidermal tissue and deep-layer tissue of the skin using difference in properties (optical properties, electric properties, and temperature difference) therebetween, and the roughness distribution pattern of the deep-layer tissue of the skin wherein visual observation is difficult due to shielding with epidermis is clearly detected.

Furthermore, the pattern of the deep-layer tissue is covered with the epid...

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