Device for removing complex background interference in criminal investigation fingerprint imaging

Abstract

The invention discloses a device for removing complex background interference in criminal investigation fingerprint imaging. The device comprises a cassette, wherein a lens connecting hole and an imaging area selecting hole which are opposite to each other are respectively formed in the top and the bottom of the cassette; an inclined directional reflection mirror is arranged right below the lens connecting hole inside the cassette; an incident light source is arranged on a side surface opposite to the lower surface of the directional reflection mirror, of the cassette; the directional reflection mirror is used for vertically reflecting a light beam emitted from the incident light source to the imaging area selecting hole; and the background and fingerprint in the imaging area selecting hole are radiated by the reflection light. By adopting the device for removing complex background interference in criminal investigation fingerprint imaging, according to optical principles and optical reflection principles, radiation light is artificially added to a fingerprint position, the intensity of the radiation light, the diameter of the light beam and the position of the light beam are changed, light reflected by the surface of an object is not accordant with light reflected by the fingerprint, and thus the fingerprint can be imaged clearly conveniently.

Description

technical field [0001] The invention belongs to the field of criminal investigation fingerprint extraction, and more specifically relates to a complex background interference removal device when criminal investigation fingerprints are photographed. Background technique [0002] Fingerprints Fingerprints are caused by grease, sweat or even dust on human fingers. After touching the surface of an object, a certain amount of grease, sweat or even dust is left on the surface of the object. In criminal investigation fingerprint extraction, for the display of fingerprints, the traditional display methods include powder display method, chemical display method, etc. Whether it is powder or chemical reagents, there is a certain amount of damage to the fingerprint material. For example, the use of powder brushes to display fingerprints, and brush tools such as hair brushes have a certain destructive effect on the details of fingerprint lines during the brushing process, affecting the ...

AI Technical Summary

Problems solved by technology

[0004] However, in actual use, it is found that many fingerprints are mostly printed on the surface of objects with relatively dark colors or patterns, which leads to a lot of interference from the background to the fingerprints during fingerprint shooting, and it is difficult to clearly photograph the fingerprints.

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