Finger and palm print instrument used for collection of soaked finger and palm prints

Abstract

The invention relates to a finger and palm print instrument used for collection of soaked finger and palm prints. The finger and palm print instrument comprises a light source, a prism and a reception system. The reception system includes a lens and an image receiver. And the prism consists of a light incidence plane, an image output plane and a collection plane. Light emitted by the light sourceenters the prism through the light incidence plane and irradiates on the collection plane where a palm print and the prism are contacted so as to carry out scattering; parts of scattered light is emitted by the image output plane and then is imaged on the image receiver through the lens; besides, an included angle A between a trajectory L1 of a light and a collection plane normal L2 is greater than a critical angle B1 that is formed by emission of the light from a glass medium into water as well as is less than a critical angle B2 that is formed by emission of the light from a glass medium toa finger skin and grease mixing medium, wherein the light enters the lens and is superposed with an optical axis of the lens as well as is transmitted in the prism and is intersected with the collection plane. According to the invention, on the premise that there is no image detail loss, a problem of imaging blurring of a finger and a palm on the moist and soaking conditions can be effectively solved.

Description

Technical field [0001] The invention belongs to the technical field of optical instruments, and relates to a finger and palm print collection instrument, in particular to a finger and palm print collection instrument that can be used for water-immersed finger and palm print collection. Background technique [0002] The quality of human finger and palm prints and the collection environment have a great impact on the collection of the finger palm print instrument, such as dry fingers, wet fingers, and dirty hands. The damp and cold collection environment has made very high requirements for the finger and palm print collection technology. Especially in some special environments, when collecting the finger and palm prints, you often have to face the freshly washed or watered In this case, the image collected by the palmprint meter is usually blurred and the contrast of the texture is very poor. [0003] There are also some methods to solve the problem of blurred images of immersed fin...

AI Technical Summary

Problems solved by technology

Humid and cold collection environments have made high demands on the fingerprint collection technology, especially in some special environments, when collecting finger prints, it is often necessary to face freshly washed or water-drenched In this case, the image collected by the palmprint device is usually blurred and the texture contrast is poor

[0003] There are also some methods to solve the problems of blurred and poor texture contrast of water-soaked fingers and palmprints, such as reducing the brightness of lighting and enhancing the contrast through electronic image processing

However, these two methods can only alleviate the problem of poor texture contrast, but cannot fundamentally solve the problem, especially the method of using electronic image processing to enhance the contrast will cause the loss of image details, thereby reducing the resolution of the fingerprint sensor. Rate

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