Patent US3918980A successfully refreshed from Google Patents.
Patent US4379178A successfully refreshed from Google Patents.
US4379178A
Expired / Lapsed
US
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Fingerprinting system
Assignee: Dactek International Inc
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Filing: 1981-03-27
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Granted: 1983-04-05
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Expires: 2001-03-27
Abstract
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.
Inventors
- 👤 Louis B. Meadows
- 👤 Arthur S. Diamond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:14
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/117; A61B5/1171; A61B5/1172
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
128 words
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.
Claim 2
Independent Claim
128 words
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.
Claim 3
Dependent Claim
29 words
A method according to claim 1 in which the metal salt is dissolved in an aqueous solution impregnated into a porous pad and said solution also contains a humectant.
Claim 4
Dependent Claim
22 words
A method according to claim 2 in which the pad is a porous plaster containing a finely divided silica or metal silicate.
Claim 5
Dependent Claim
15 words
A method according to claim 3 in which the metal salt is an iron chloride.
Claim 6
Dependent Claim
20 words
A method according to claim 4 in which the iron chloride is a mixture of ferrous chloride and ferric chloride.
Claim 7
Dependent Claim
36 words
A method according to claim 2 further including the step of removing any developed image remaining on body part by wiping the body part with a fibrous substrate impregnated with a solvent for the developed image.
Claim 8
Dependent Claim
19 words
A method according to claim 1 in which the card is impregnated only in the fingerprint receiving area thereof.
Claim 9
Dependent Claim
21 words
A method according to claim 1 in which the developer compound comprises a mixture of a quinolinol and a trihydroxy phenol.
Claim 10
Dependent Claim
20 words
A method according to claim 8 which the acid is azelaic acid and the mixture comprises 8-hydroxyquinoline and propyl gallate.
Claim 11
Dependent Claim
76 words
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.
Claim 12
Dependent Claim
76 words
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.
Claim 13
Dependent Claim
14 words
A card according to claim 10 in which only said second area is impregnated.
Claim 14
Dependent Claim
15 words
A card according to claim 10 in which the mixture comprises 8-hydroxy-quinoline and propyl gallate.
Claim 15
Dependent Claim
17 words
A card according to claim 12 in which the dibasic acid contains 8 to 18 carbon atoms.
Claim 16
Dependent Claim
14 words
A card according to claim 10 in which the dibasic acid is azelaic acid.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-04-04 | 1986-10-04 | 1987-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-04 | 1990-10-04 | 1991-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-04 | 1994-10-04 | 1995-04-05 | $7700.00 | Window Closed / Lapsed |