The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 17, 1990
Filed:
Nov. 09, 1988
Douglas C Arndt, Thousand Oaks, CA (US);
Virgle L Hedgcoth, Pomona, CA (US);
Identicator Corporation, San Bruno, CA (US);
Abstract
A method for enhancing fingerprint images comprises the steps of applying a chemical compound to the fingers to be printed in which the compound contains a first constituent in the form of a conventional ink or inkless reagent. The first constituent is arranged by itself (i.e., ink) or in conjunction with a developer (i.e., inkless) to provide a visible image of a fingerprint when applied to a porous surface, such as a conventional fingerprint card under light within the visible spectrum. A second constituent is included in the compound which is arranged to fluoresce within the visible spectrum (i.e., 500 to 650 nm) when subject to U.V. radiation, preferably centered at 550 nm. The compound from the fingers is then deposited onto a porous surface and a visible image is formed therefrom representing the ridge patterns of the fingers. The surface is then illuminated with visible and ultraviolet light and the fluorescence of the second constituent enhances the brightness of the image. The image is focused onto a photosensitive surface (e.g., video camera tube or photographic film) having a maximum sensitivity to light within the yellowish-green spectrum and the image is converted into information representative of the ridge patterns of the fingers (e.g., by computer or development of the film.