Method for authenticating uv absorbing security mark

Abstract

A method of authenticating a document includes providing a document having a substrate comprising an optical brightener; printing a background with a ultraviolet (UV) absorbing material on the substrate comprising a first pattern of lines having a first frequency and a first orientation; printing a security mark with the UV material on the substrate comprising a second pattern of lines having a second frequency or a second orientation or both; placing a lenticular lens over the security mark and background; illuminating the security mark and background through the lenticular lens with UV light; orienting the lenticular lens to match either the first orientation or the second orientation; and authenticating the document if the security mark matches a predetermined security mark.

1 . A method of authenticating a document comprising:
 providing a document having a substrate comprising an optical brightener;   printing a background with a ultraviolet (UV) absorbing material on the substrate comprising a first pattern of lines having a first frequency and a first orientation;   printing a security mark with the UV material on the substrate comprising a second pattern of lines having a second frequency or a second orientation or both;   placing a lenticular lens over the security mark and background;   illuminating the security mark and background through the lenticular lens with UV light;   orienting the lenticular lens to match either the first orientation or the second orientation; and   authenticating the document if the security mark matches a predetermined security mark.   
     
     
         2 . The method of  claim 1  wherein the predetermined security mark is selected from a group consisting of an image, a logo, a series of numbers or letters or both, a bar code, or a hash tag. 
     
     
         3 . The method of  claim 1  wherein the first orientation differs from the second orientation by at least 10 degrees. 
     
     
         4 . The method of  claim 1  wherein the orientation of the lenticular lens differs from either the first orientation or the second orientation by less than 5 degrees. 
     
     
         5 . The method of  claim 1  wherein the first frequency is equal to the second frequency. 
     
     
         6 . The method of  claim 1  wherein the first orientation is equal to the second orientation and the first and second frequencies are different. 
     
     
         7 . The method of  claim 1  wherein the frequency of the lenticular lens is a multiple of the first or second frequency. 
     
     
         8 . The method of  claim 1  wherein the frequency of the lenticular lens is equal to the first or second frequency. 
     
     
         9 . The method of  claim 1  wherein the authentication is a visual match with a predetermined security mark. 
     
     
         10 . A method of authenticating a document comprising:
 providing a document having a substrate comprising optical brightener;   printing a background with a ultraviolet (UV) absorbing material on the substrate comprising a first pattern of lines having a first frequency and a first orientation;   printing a security mark with the ultraviolet (UV) material on the substrate comprising a second pattern of lines having a second frequency or a second orientation or both;   illuminating the security mark and background with UV light;   capturing an image of the security mark and background with an image capture device;   applying an image transformation algorithm to the captured image;   displaying the transformed image on the display of the image capture device; and   authenticating the document if the security mark matches a predetermined security mark.