Abstract:
This invention relates generally to document protection methods and product. More specifically, the present invention relates to a method for hiding information in a document by means of a latent image or message, which is practically invisible to the naked eye and may only be revealed through use of a matching viewing device. The present invention further relates to a method for creating original documents containing latent messages, which are revealed when the document is read by a viewing device. In one embodiment, print elements such as lines, dots, spots, swirls, or images are used to form covert information. The covert information print elements are disposed at an angle to print elements of a background, thus creating a covert document. In another embodiment, print elements of the covert information are used with a solid background.

Description:
RELATED APPLICATION  
       [0001]     Priority for the present application is based on U.S. Provisional Patent Application 60/703,860, filed Aug. 1, 2005, and 60/794,826, filed Apr. 26, 2006. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention relates generally to document protection methods and product. More specifically, the present invention relates to a method for hiding information in a document, by means of a latent image or message, which is practically invisible to the naked eye and may only be revealed through use of a matching viewing device. The present invention further relates to a method for creating original documents containing latent messages, which are revealed when the document is read by a dedicated viewing device.  
       BACKGROUND OF THE INVENTION  
       [0003]     Secure documents have been produced in the past by letterpress, offset or intaglio printing processes. At present there exists a need for secure documents to be printed not only over the internet and output on a printer, but also the ability to remotely print tickets and coupons that contain common security features and individualized “hidden” information.  
         [0004]     Additionally, the need exists for secure images for solid color printed areas. In the past, most security tints were comprised of dot and line screens, usually not over 50% in density, but as a need for packaging security is on the increase, there exists a need to add security features to printing designs. More specifically in pharmaceutical and automotive packaging, most artwork designs contain an increasing number of solid color areas that traditionally have not contained any printed security.  
       SUMMARY OF THE INVENTION  
       [0005]     It is an object of the present invention to provide enhanced security for covert documents that are to be embedded with variable and/or static covert information. It is understood for all of the following embodiments that a document can take many forms, including an electronic document as well as a hard copy.  
         [0006]     There is thus provided in accordance with one embodiment of the present invention, an advanced method of concealing covert information in a document that is transmitted (for example, over the internet, extranet, wireless, facsimile, etc.), copied, or otherwise successfully reproduced on an output device such as a printer. Covert information is hidden by creating a first and a second print structure and then combining them.  
         [0007]     There is also provided in accordance with another embodiment of the present invention, a tint for concealing the covert information from unintended users. The covert information is hidden from view by means of an apparently solid tint, which does not reveal information when viewed with the naked eye, photocopied, scanned or digitally photographed. Any attempt to reproduce or copy the document in any way may result in an unreadable tinted area. Alternatively, the document may be copied in substantially identical form including the covert information, which remains masked from the naked eye, but is still viewable by a dedicated viewing device, even after transmission, copying, or other reproduction.  
         [0008]     Further, in accordance with an embodiment of the present invention, the step of masking the covert information may be achieved using any color, ink, toner or inkjet fluid. The step of masking the covert information is most effectively achieved using a dark tint, or metallic or UV/IR inks. The step may be further effectively achieved by printing specific frequencies over a foil image.  
         [0009]     Additionally, in accordance with an embodiment of the present invention, the step of masking the covert information is achieved utilizing lines, dots, spots, swirls, or images, generally referred to as print elements, either individually or in combination. The step of masking the covert information is most effectively achieved using print elements of equal size and density.  
         [0010]     Still further in accordance with an embodiment of the present invention, the print elements of the covert information should be placed at substantially orthogonal angles to each other in order to most effectively conceal information. The most effective positioning of the screens would be 135°/45°, with one angle for the covert information and one angle for background.  
         [0011]     Further, in accordance with an embodiment of the present invention, the step of establishing the angles of the print elements is dependent on defining the print element screens. The print element may be imaged between 60 and 500 lines per inch, and may be most effective at 150 lines per inch for covert information and the surrounding areas. Screen frequency units most commonly used are lines per inch (“lpi”), but it is understood that print elements other than lines could be utilized; “lpi” is still used as a frequency unit as a matter of convenience. Additionally, the density of the covert information print element tint may be between 10% and 50%, preferably at or about 20%.  
         [0012]     Additionally, for the embodiment of the present invention that is incapable of being transmitted, copied, or reproduced, several print element screens are the most effective at not being reproduced, namely 60-300 lpi, and most preferably 120-190 lpi.  
         [0013]     In accordance with an embodiment of the present invention, there is provided a dedicated viewing device, which is specifically suited to the document, substantially matching the frequency of the covert information print elements. When held in a substantially flat position against the covert information on the document, the dedicated viewing device reveals it while making the background appear less noticeable.  
         [0014]     Further, in accordance with an embodiment of the present invention, the dedicated viewing device may be a lens made of either plastic, glass or film substrate. Dedicated viewing devices may be designed to be easily destroyed after use to ensure extra document security. The dedicated viewing device may be clear, tinted or lined to assist the viewing of the covert information and may contain several distinct areas for viewing of multiple screened areas.  
         [0015]     Implementation of the method and system of the present invention involves performing or completing selected tasks or steps manually, automatically, or a combination thereof. Moreover, according to actual instrumentation and equipment of preferred embodiments of the method and system of the present invention, several selected steps could be implemented by hardware or by software on any operating system of any firmware or a combination thereof. For example, as hardware, selected steps of the invention could be implemented as a chip or a circuit. As software, selected steps of the invention could be implemented as a plurality of software instructions being executed by a computer using any suitable operating system. In any case, selected steps of the method and system of the invention could be described as being performed by a data processor, such as a computing platform for executing a plurality of instructions. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     The present invention will be more fully understood an appreciated from the following detailed description, taken in conjunction with the drawings, in which:  
         [0017]      FIG. 1  is an illustration of one embodiment of the present invention where covert information is being revealed through a dedicated viewing device.  
         [0018]      FIG. 2  is a simplified illustration of solid lines of the covert information disposed at a different angle to the solid lines of the background.  
         [0019]      FIG. 3  is a simplified illustration of the solid lines of the covert information containing a print code.  
         [0020]      FIG. 4  is a simplified illustration of another embodiment of the present invention using a solid tint background with print elements of the covert information. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]     The present invention provides a method of masking information from unintended users and enabling observation of information through a dedicated viewing device.  
         [0022]     In a typical scenario, in accordance with the present invention, a user wanting to convey covert information contained within a document to a specific recipient may provide the recipient with a matching viewing device designed to match the document and recognize the covert information. The covert information may be concealed from view and may not be accessed unless a suitable viewing device is used. Any other recipient of the same document would not have access to the covert information concealed from view and would be unaware of the covert information present within the document or would only be privy to specific information located on a specific area of the document.  
         [0023]     Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways, such as laminates or holographic foils. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.  
         [0024]     Referring now to  FIG. 1 , a covert document form  100  contains covert information  101 , background  102 , and fillable field  105 . Also shown is dedicated viewing device  110 .  
         [0025]     In one embodiment of the present invention, the user inserts covert information  101  into background  102 , as described in detail below. Covert document  100  is then ready to be transmitted, copied, or otherwise successfully reproduced by an output device (not shown). The output device may be a copier, scanner, fax machine, or the like.  
         [0026]     In a typical scenario, a person wishing to send covert information  101  over the internet may use form  100  on a computer that has fillable field  105 . Covert information  101  may be entered into fillable field  105  either by the person completing the form  100  and/or the receiver of the form  100 , who may want at least some of the details being sent to remain confidential. Either during or following the entry of the covert information  101  into fillable field  105 , covert information  101  is embedded in background area  102  of document  100  as described below and shown in  FIGS. 2 and 3 . The form  100  may then be transmitted through electronic means, e.g., through the internet or by facsimile. In one embodiment of the invention, form  100  may be sent to an intermediate or a terminal service where the visible information in fillable field  105  may be removed leaving only the information hidden in background  102  for viewing by dedicated viewing device  110 .  
         [0027]     Dedicated viewing device  110  may be a lens made of either plastic, glass or film having a print element frequency that matches the print element frequency of covert information  101 . Dedicated viewing device  110  may be clear, tinted or lined to assist the viewing of the covert information  101  and may contain several distinct areas for viewing of multiple screened areas.  
         [0028]     For operation, dedicated viewing device  110  is simply held against covert information  110  for viewing. Use of the dedicated viewing device  110  may make the appearance of the image of background  102  paler or less noticeable while revealing covert information  101 , as shown in  FIG. 1 .  
         [0029]     Dedicated viewing device  110  may be designed to be easily destroyed after use to ensure extra document security.  
         [0030]     In an alternative embodiment of the invention, the visible information disappears from the form  100  during or after embedding covert information into background area  102 , thus rendering the electronic document free of information intended to be covert. With fillable field  105  rendered blank, an unintended viewer would not have access to the covert information  101 . An intended user may then use dedicated viewer  110  to view covert information that has been embedded in background area  102 . Most preferably, covert information  101  and background  102  may be created by using a software program such as Forms X6 for Quark Xpress by DigiComp, Maple Grove, Minn.  
         [0031]     Reference is now made to  FIG. 2 , which is a simplified illustration of one embodiment of the present invention  200  having solid lines  201  and  202  at substantially different angles to each other to mask covert information  201 . A user wanting to conceal covert information  201  from general view, may place covert information print elements, in this case, solid lines,  201 , and background print elements, in this case, solid lines,  202 , at substantially different angles to each other. Print elements of covert information  201  define axis x 2  and print elements of background  202  define axis y 2 . Angle b between axes x 1  and y 1  preferably measures 90°, plus or minus 5°, as shown in  FIG. 2 , but can, in actuality, vary greatly. Of course, covert information print elements  201  and background print elements  202  could be replaced with dots, spots, swirls, or images (not shown), either individually or in combination.  
         [0032]      FIG. 3  is a simplified illustration of one embodiment of the present invention  300  similar to  FIGS. 1 and 2 , having solid lines as print elements of the covert information and background,  301  and  302 , respectively. Axes x 3  and y 3 , defined by print elements  301  and  302 , are disposed at angle c, again preferably 90°, plus or minus 5°, to mask the covert information. Additionally, print code  303  is inserted, preferably, at the vertex of angle C. Print codes can be used for additional security, authorship identification, or the like. Print code  303  is shown as the lower case letter “w” in  FIG. 3 , but can be comprised of any print element, including, but not limited to, lines, dots, spots, swirls, or images.  
         [0033]      FIG. 4  is a simplified illustration of another embodiment of the present invention  400  in which covert information  402  cannot be easily scanned or copied. Covert information print elements  402 , shown as broken lines, are used in combination with solid background  401 , shown as solid lines in  FIG. 4 . By selecting the proper tints, print elements  401  can be hidden within solid background  401  and later viewed using a dedicated viewing device (not shown). Darker tints are preferred for solid background  401  and colored tints are preferred for covert information print elements  402 .  
         [0034]     A user wanting to isolate covert information  402  as shown in  FIG. 4  may cover or underlay the covert information print elements  402  with a tint, color, paper substrate coloring or foil. Information displayed in this manner is seen as a solid tint. Covert information  402  may be most effectively concealed through the use of dark colors, metallic colors and/or UV inks. The user may choose to use a solid printed or tinted background or colored paper in addition to the dark or metallic or UV/IR ink. For example, the user may choose to print with blue ink on red paper, or red on a metallic blue solid area.  
         [0035]     The metallic base tint may be overprinted with an opposite color that would further hide the covert information. UV and IR links used to create the information may be placed to reveal half of an image when a plastic or glass viewer is placed on top of the document and the balance of the image “appears when UV or IR light is shown through the viewing device onto the document. In such a way, additional “codes” may be hidden as secondary messages.  
         [0036]     In all of the above embodiments, the user, having chosen to reveal covert information  101  to a recipient of the document, provides the recipient with a dedicated viewing device, shown as  110  in  FIG. 1 . If multiple areas of the document are used to hide multiple portions of covert information  101  and different recipients are intended to view different areas of covert information  101 , the user provides each recipient of the document with a different viewing device  110 , each designed to match the different covert information. The process can be accomplished by utilizing a different screen frequencies or different screen print elements, such as dots as covert information print elements for the first recipient and lines as covert information print elements for the second recipient. Alternatively, a page of a document containing a tint background may be transmitted and separately covert information printed to a translucent overlay may be transmitted such that when the overlay is placed over the background screen the covert information may be read.  
         [0037]     Additional objects, advantages, and novel features of the present invention will become apparent to one ordinarily skilled in the art upon examination of the following examples, which are not intended to be limiting. Additionally, each of the various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below, finds experimental support in the following examples.  
         [0038]     It is appreciated that certain features of the invention, which are for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination, such as a document with specific covert information revealed partially by a laminate viewing device permanently affixed to the document that also contains additional covert information at a first, second or third print element frequency and or ink make-up.  
         [0039]     Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. All publications, patents and patent application mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention