Fingerprinting system
AssigneeDactek International, Inc.
InventorsLouis B. Meadows, Arthur S. Diamond
Life of this patent
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Abstract
Fingerprints images are formed by applying the distal portion 29 of a finger 32 to a porous pad 10 impregnated with a solution of marking compound. The finger portion may be prewetted or cleaned with cloth 30 impregnated with detergent solution. The finger 32 is then applied to a square 36 of a fingerprint card 38 impregnated with an aqueous solution of polyhydroxy developer such as 8-hydroxy-quinoline and propyl gallate containing a high molecular weight dibasic acid such as azelaic acid. A fingerprint image 40 immediately develops. Traces of the image can be removed with a cleaning solution impregnated cloth 42.
Claims14
A method of producing a print of a finger or other body part comprising the steps of:
- applying an aqueous solution of a color-forming, water-soluble, metal salt compound to said part to form an invisible, latent pattern;
- transferring said invisible pattern to a card impregnated with 10 to 40 parts by weight of a developer for said metal compound comprising a mixture of at least one water-soluble color developing compound selected from a polyhydroxy aromatic compound, a quinolinol compound and mixtures thereof with 1 to 10 parts by weight of a viscosity control agent consisting essentially of a dibasic organic acid containing from 8 to 18 carbon atoms;
- and
- forming a dark image on said card by reacting said pattern of metal salt compound with said color-forming developer.
A fingerprint imaging device comprising:
- a card having a first information receiving area and a second fingerpring receiving area;
- at least said second area being impregnated with a mixture of a water-soluble developer capable of developing invisible, latent patterns of water-soluble transition metal salts selected from at least one of a polyhydroxy compound and a quinolinol with 2 to 8 percent by weight of a water-soluble dibasic fatty acid containing from 8 to 18 carbon atoms.
Dependencies are inferred from the claim text.