A wet finger fingerprint collection device

Abstract

A fingerprint acquisition device for a wet finger comprises a shell body and an optical fingerprint imaging module arranged in the shell body. The optical fingerprint imaging module comprises a prism, an imaging objective lens, a fingerprint image acquisition unit and an LED light source, wherein the prism, the imaging objective lens, the fingerprint image acquisition unit and the LED light source are arranged according to a light path. The prism is made of glass with a refractive index of at least 1.7. A light patch between the prism and the imaging objective lens is provided with a first plane mirror and a second plane mirror, the intersection angle between the first plane mirror and the large end face of the prism is 97.1 degrees, light rays reflected by the first plane mirror enter the second plane mirror, the intersection angle between the second plane mirror and the large end face of the prism is 13 degrees, and light rays reflected by the second plane mirrors directly enter the imaging objective lens. The problem that the high-quality fingerprint image of the wet finger cannot be acquired due to the fact that the refractive index of water is lower than that of glass in an existing fingerprint acquisition device is solved, the fingerprint lines of an acquired fingerprint image of the wet finger can be clearly seen, the fingerprint acquisition device can be applied to register and comparison, and the size of the fingerprint acquisition device for the wet finger is obviously reduced.

Description

technical field [0001] The invention relates to a biometric identification method or device using an electronic circuit, in particular to a wet finger fingerprint collection device. Background technique [0002] Fingerprint identification technology has the characteristics of convenience, reliability, non-invasiveness and relatively low cost. It distributes user fingerprint data to corresponding fingerprint verification devices, uploads fingerprint pressing records in real time, generates fingerprint pressing reports, and provides evidence for tracing accidents. Fingerprint identification is closely related to the quality of the collected fingerprints, and there are corresponding requirements for the fingers of the person being collected, especially for fingerprint collection devices used in access control or outdoors, there are stricter requirements for the fingers of the person being collected, for example Wet, too dry, or too peeling. However, in real life, fingers will ...

AI Technical Summary

Problems solved by technology

However, in real life, fingers will sweat or inevitably become wet when they come into contact with water. Since the refractive index of water is lower than that of glass, it directly affects the quality of wet finger fingerprint images collected by existing fingerprint collectors. The quality of the fingerprint image is very poor, the fingerprint lines cannot be seen, and the registration comparison cannot be performed

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