Method of making permanent images on recording surface having a thermosensitive color-developing layer thereon
Patent 4983415 Issued on January 8, 1991. Estimated Expiration Date: 
July 21, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 21, 2009. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesTwo-part inkless applicator for fingerprints Imaging compositions and methods Plastic identity card capable of providing an inkless fingerprint and method of developing inkless prints on plastic card Fingerprinting compositions, systems and methods Patent #: 4879134 InventorsAssigneeApplicationNo. 383971 filed on 07/21/1989US Classes:427/1BODY MEMBER PRINTING (E.G., FINGERPRINTING, ETC.)ExaminersPrimary: Bell, JanyceAttorney, Agent or FirmForeign Patent References
International ClassA61B 005/117AbstractAn inkless method of recording an image of a desired object or symbol such as the print of a person's finger is described in which a recording surface is prepared by placing thereon a thermosensitive color-developing layer comprising a chromogenic dye such as a leuco dye, an organic acid developer, such as a phenolic compound, reactive with the dye to form a color and a thermosensitive barrier layer separating the dye and developer. A chemical reagent containing one or more metallic slats, such as ferric chloride, in the format of the desired object or symbol, is applied to the recording where the reagent reacts with the developer and/or dye in the thermosensitive color-developing layer to form a permanent two-dimensional image of the object or symbol such as the ridge pattern of the person's finger. | |
