Patterned platelets

Abstract

Patterned platelets are platelets made with specified shapes and sizes. The various sizes and shapes of the platelets are used to code articles and substances to which they are applied. The patterned platelets can be in inks or paints applied to articles. The platelets can be further coded by markings thereon or by spectral or polarization codes rather than just the distribution of sizes and shapes. The patterned platelets can be made from any materials buy subtractive or additive processes. A patterned platelet can also be made by an actinic polymer being applied to a substrate and a mask applied to allow only the desired size and shape to be exposed to radiation curing the unmasked portion of the polymer on the substrate. The polymer can be cholesteric liquid crystals with the properties of reflecting polarized light of selected wavelengths to code the crystals in addition to the size and shape codes. The cholesteric liquid crystals may also be doped with materials which absorb a portion of the wavelengths which would otherwise be reflected further coding the patterned platelets. Codes of the patterned platelets can be composed of the distribution of the platelets alone or in combination with the position of the platelets on an object A code with the presence or absence of a specified patterned platelet in a specified location could be a binary code. If n different patterned platelets are used in each of x positions a code with x to the nth-power combinations is possible.

1 - 26 . (canceled) 
   
   
       27 . A code comprising patterned platelets. 
   
   
       28 . A code as in  claim 27  wherein,
 the code comprises one or more features of the patterned platelets chosen from the group consisting of specified shapes, specified sizes, spatial markings, percentage distributions of coded patterned platelets, spectral markings, polarization markings and angle of viewing codes.   
   
   
       29 . A code as in  claim 27  wherein,
 the positions of the patterned platelets relative to each other on an article are part of the code.   
   
   
       30 . A code as in  claim 29  wherein,
 the code comprises one or more features of the patterned platelets chosen from the group consisting of blank spaces, specified shapes, specified sizes, spatial markings, percentage distributions of coded patterned platelets, spectral markings, polarization markings and angle of viewing codes.   
   
   
       31 . An coded ink comprising:
 an ink carrier,   a code of a plurality of coded patterned pigments in the ink carrier.   
   
   
       32 . A coded paint comprising:
 a paint carrier,   a code of a plurality of patterned pigments in the paint carrier.   
   
   
       33 . A coded paint as in  claim 32  wherein the paint is applied to an article to code the article. 
   
   
       34 . A coded ink as in  claim 31  wherein the ink is applied to an article to code the article. 
   
   
       35 . A code as in  claim 27  wherein:
 the patterned platelets are applied to the surface of an article to identify it.   
   
   
       36 . A code as in  claim 27  wherein:
 the patterned platelets are mixed in with the material comprising an article to identify it.   
   
   
       37 . A code as in  claim 27  wherein:
 the patterned platelets are mixed in with a liquid to identify it.