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United States Patent   Patent Number: 4,846,502
Chang et al.  Date of Patent: Jul. 11,1989
TAMPER EVIDENT DOCUMENT AND USE THEREOF
Inventors: John C. H. Chang, Naperville;
Theodore Dimitriou, Mettawa, both
Assignee: Wallace Computer Services, Inc.,
Appl. No.: 877,760
Filed: Jun. 24, 1986
Int. CI." B42D 15/00
U.S. CI 283/57; 282/9 R;
283/59; 283/94; 283/96; 283/95; 283/901
Field of Search 282/9 R, 9 A, 11.5 R,
282/11.5 A, 10, 11, 8 R; 283/58, 901, 57, 59, 94, 70, 95, 96, 114; 346/204, 206; 428/915, 916
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4,143,891 3/1979 Neubauer .
4,317,743 3/1983 Chang .
4,360,548 11/1982 Skees et al 428/29
4,425,386 1/1984 Chang .
4,448,445 5/1984 Chang et al. .
4,496,961 1/1985 Devrient .
4,512,595 4/1985 Breen 283/95 X
4,662,651 5/1987 Mowry, Jr 283/70
4,681,348 7/1987 Mowry, Jr 283/58
FOREIGN PATENT DOCUMENTS 2600781 5/1979 Fed. Rep. of Germany .
110008 8/1979 Japan .
434475 11/1933 United Kingdom 283/94
1197406 1/1970 United Kingdom .
(Anonymous) "Security Document"; Research Disclosure; No. 187, Nov. 1979, pp. 638, 639.
Primary Examiner—Paul A. Bell
Attorney, Agent, or Firm—Roylance, Abrams, Berdo &
A tamper evident document comprising a support bearing an autogenous coating including chromogenic material isolated from an electron-acceptor color developer material in which the autogenous coating bears a principal image comprising visible indicia of a transfer medium imprinted on the surface of the localized autogenous coating. Tampering with the principal image causes chromogen to react with the electron-acceptor color developer material to provide a color indication of tampering. The tamper evident document can be part of a multi-ply record system comprising a plurality of sheets in superposed relationship, comprising a first sheet including a support bearing an autogenous coating including chromogenic material isolated from an electron-acceptor color developer material, said localized autogenous coating bearing a principle image comprising invisible indicia of a transfer medium imprinted on the surface of said localized autogenous coating, and a second sheet including a support bearing a coating of a transfer medium on the first side of said support, said second sheet being positioned adjacent said first sheet with said first side adjacent and in superposed relationship to said autogenous coating such that when pressure is applied to the second side of said second sheet transfer medium in the form of visible indicia is imprinted onto said autogenous coating, wherein tampering with said principal image causes chromogen to contact with said electron-acceptor color developer material to provide a color indication of tampering.
21 Claims, 2 Drawing Sheets
TAMPER EVIDENT DOCUMENT AND USE
FIELD OF THE INVENTION 5
This invention relates to a tamper evident document, a tamper evident multi-ply record system for creating and safeguarding negotiable instruments, a tamper evident negotiable instrument, and to the use of such tamper evident documents. More particularly, this in- 10 vention relates to tamper evident documents having autogenous coatings on which is imprinted transfer medium in the form of visible indicia.
BACKGROUND OF THE INVENTION 15
Important information is often provided on documents, such as negotiable instruments, by imprinting transfer media in the form of visible indicia onto the face of the instrument. A common transfer medium is carbon which is transferred from a sheet of carbon 20 paper placed over the face of the instrument, or ink from an inked typewriter ribbon. The transfer medium is imprinted onto the face of the instrument by typing, hand writing, mechanical means, etc. Such imprinted visible indicia is often subjected to unauthorized alter- 25 ation. The negotiable instrument may be a bank check, money order, bill of exchange, certificate of deposit, treasury check, cashier's check, traveler's check, letter of credit, warrant, airline ticket, contract, deed, securities certificates, identification card, etc. Illegal alter- 30 ations cause financial loss to the issuers resulting in costly legal action.
Several illicit practices have been commonly used to alter such instruments. For visible indicia formed by transferable ribbon, a pressure-sensitive tape has been 35 used to lift the images. For indicia formed by carbon paper, inked ribbon, and ink pens, a combination of an eraser and a sharp-edged object has been used to alter the numbers. For indicia formed by special inks, organic solvents have been used to alter such indicia. So far, no 40 known system can counter such illicit alterations.
Thus, there has been a continuing need for a tamper evident system useful for negotiable instruments and other valuable documents.
SUMMARY OF THE INVENTION 45
A tamper evident system has now been discovered which can be used to prevent illicit alternation of documents including negotiable instruments, which system comprises a support bearing an autogenous coating 50 comprising a chromogenic material isolated from an electron-acceptor color developer material, said autogenous coating adapted to receive a principal image comprising visible indicia of a transfer medium which is imprinted on the surface of the autogenous coating, said 55 autogenous coating being at least generally coextensive with said principal image, such that tampering with the principal image releases chromogen from the capsules to contact and react with the electron-acceptor color developer material and provide a visible indication of 60 tampering. The visible indication of tampering can be by color contrast between the color of the principal image (e.g., black) and the developed color of the chromogen (e.g., yellow).
According to a preferred embodiment of the present 65 invention, the chromogen is isolated from the electron acceptor material by providing the chromogen in microscopic pressure rupturable capsules. According to
another preferred embodiment of the invention, the chromogen is isolated from the electron-acceptor color developer material by means of a barrier coating.
According to a further embodiment of the invention tampering is indicated by a message appearing when chromogen is released and reacts with the electronacceptor color developer material. According to this embodiment of the present invention, the autogenous coating comprises a first layer comprising a latent image of a message, such as "VOID" formed of the electronacceptor color developer material, and a second adjacent layer including chromogen-containing microscopic pressure rupturable capsules. Alternatively, the latent image can be printed using the chromogen in an ink base and coated with a barrier layer followed by a layer of Lewis acid electron-acceptor color developer to form the autogenous coating.
According to another embodiment of the present invention the tamper evident document of the present invention is a negotiable instrument where the principal image is a monetary amount, such as in the case of a money order. In such embodiment, the tamper evident document is contained in a multi-ply record system comprising a plurality of sheets in superposed relationship, comprising a first sheet including a support bearing an autogenous coating comprising a chromogenic material isolated from an electron-acceptor color developer material, said autogenous coating bearing visible indicia of a transfer medium imprinted on the surface of the autogenous coating as the principal image, said autogenous coating being at least generally coextensive with said principal image and, preferably, a localized coating generally coextensive with said principal image. A second sheet including a support bearing a coating of a transfer medium on the first side of the support with the second sheet being positioned adjacent the first sheet with the first side adjacent and in superposed relation to the autogenous coating, such that when pressure is applied to the second side of the second sheet, the transfer medium in the form of visible indicia will be imprinted onto the autogenous coating to form an imprinted visible indicia, which, if tampered with, will reveal a color indication of tampering in the areas the tampering occurred.
According to another preferred embodiment of the present invention, a second localized autogenous coating is provided on the surface of the support opposite and at least generally coextensive with the principal image. This not only permits the imprinting of a mirror image of the monetary amount, but can further reveal any tampering with the principal or mirror image.
According to a still further embodiment of the present invention, a method for the protection of imprinted documents, such as wills, is provided, which comprises providing a supporting bearing generally coextensive autogenous coatings on opposite sides of said support such that tampering with said printed indicia is revealed by release of said chromogen from said microscopic capsules to form a contrasting color in the areas of tampering.
As used in the present application, the term "principal image" is defined as a visible image of a transfer medium subject to alteration. The principal image can be a monetary amount in numerical ("$25.00") or written (twenty-five dollars") form on a negotiable instrument, such as a money order or check, which has been transferred to the surface of the autogenous coating,