4 results about "Latent fingerprint" patented technology

This invention discloses a method, system, terminal, and medium for wet latent fingerprint recognition based on a humidity-adaptive optical storage device. The method includes: acquiring an original wet latent fingerprint image; converting the original wet latent fingerprint image into an ultraviolet light pulse sequence adapted to the optical response characteristics of the humidity-adaptive optical storage device; constructing a reservoir array based on the humidity-adaptive optical storage device; receiving the ultraviolet light pulse sequence based on the reservoir array; outputting a current amplitude signal matching the fingerprint features of the corresponding pixel based on the humidity-adaptive optical storage device's adjustable and adaptive characteristics; and outputting a feature vector carrying the core features of the wet latent fingerprint based on the current amplitude signal; inputting the feature vector into a neural network for fingerprint recognition; and outputting the fingerprint recognition result based on the readout layer of the neural network. This invention effectively solves the core problems of low recognition accuracy, high latency, and high energy consumption in high humidity environments, significantly improving the efficiency and reliability of wet latent fingerprint recognition.

This invention discloses BODIPY dyes, their preparation methods, and their applications in latent fingerprint recognition. The invention prepares four BODIPY dyes with different structures and emission colors, all exhibiting high fluorescence quantum yields (over 55% absolute fluorescence quantum yield) and excellent lipophilicity. Using a spray method, latent fingerprints on different substrates can be efficiently and conveniently detected within 10 seconds. Furthermore, the detection solution demonstrates excellent stability, can be stored for up to 30 days, and achieves a color change from green to red through modulation. This modulation effectively addresses complex background colors, ensuring optimal latent fingerprint detection results under various color backgrounds.

This invention provides a protein-targeting bifunctional blue developing agent. Commercially available Prussian blue (Tianjin Zhonglian CAS: 14038-43-8) is used, with water as the solvent and benzalkonium chloride as the dispersant, and is ultrasonically dissolved to form a 4% (w / w) Prussian blue aqueous solution. It can be used to develop latent fingerprints or blood fingerprints containing grease on a sample using methods such as drop casting, spraying, and immersion. Under ambient light, the fingerprint turns blue under the action of the developing solution. This invention is applicable to most non-permeable samples and some semi-permeable samples. The dye formulation provided by this invention has low cost, simple preparation, rapid color development, easy operation, and is environmentally friendly. It can broaden new methods for fingerprint development in criminal investigations.

This invention discloses a fingerprint development reagent based on natural AIE compounds and precipitated silica, its preparation method, and its application, belonging to the field of forensic identification technology. The reagent is a particulate suspension comprising precipitated silica, natural AIE compounds, a surfactant, and a solvent. During preparation, the surfactant is dissolved in the solvent, the natural AIE compound is added and dissolved, and then precipitated silica is added in batches with stirring to obtain a uniform and stable suspension. This invention uses naturally derived AIE active substances, which are non-toxic, environmentally friendly, and low-cost, avoiding the biotoxicity and complex preparation process of traditional synthetic dyes. It also effectively solves the problems of dust pollution and poor compatibility with moist objects in powder development methods. It achieves high-contrast, high-definition fluorescence development of latent fingerprints on both dry and moist, non-permeable surfaces. The preparation process is simple and controllable, easy to scale up, and has good application prospects in rapid on-site detection fields such as criminal investigation and forensic identification.