Medium for laser printing including optical special effect flakes

Abstract

A laser toner includes optical effect taggent flakes or other structures in a binder suitable for binding particles to a substrate. Preferably the optical effect taggent structures have a substantially same shape or same indicia within the binder sized to be suitable for laser printing. After printing the flakes or structures become bonded to the substrate they are printed upon and are discernable by viewing with magnification.

1 . A medium for laser printing, comprising:
 a binder suitable for binding particles to a substrate; and   a first plurality of optical effect taggent structures having a substantially same shape or same indicia within the binder sized to be suitable for laser printing, wherein said structures are discernable upon viewing with magnification.   
     
     
         2 . A medium as defined in  claim 1 , wherein the binder is a polymeric binder material and wherein the first plurality of special effect taggent structures are dispersed within the binder material. 
     
     
         3 . A medium as defined in  claim 1 , wherein first plurality of taggent optical effect structures are coated with the binder. 
     
     
         4 . A medium as defined in  claim 1  wherein the optical effect taggent structures are flakes and wherein the medium further comprises a toner material that is visually distinguishable from the taggent flakes. 
     
     
         5 . A medium as defined in  claim 4 , further comprising toner, wherein the first plurality of optical effect taggent structures having an identifiable feature that when magnified, distinguishes them from the binder. 
     
     
         6 . A medium as define in  claim 5 , wherein the taggent structures are flakes which are at least one of: a substantially same predetermined shape, color shifting flakes, flakes having indicia thereon, and diffractive flakes. 
     
     
         7 . A medium as defined in  claim 3 , wherein at least some of the taggent structures have indicia therein or thereon that can be seen with magnification, and wherein the indicia are smaller than 20 microns. 
     
     
         8 . A medium as defined in  claim 4  wherein the taggent flakes are less than 50 microns across their surface. 
     
     
         9 . A medium as defined in  claim 4 , wherein the taggent flakes each comprise a layer of metal or a single layer or a multilayer of dielectric materials. 
     
     
         10 . A medium as defined in  claim 8 , wherein the metal is Al. 
     
     
         11 . A medium as defined in  claim 9 , wherein the layer of metal supports one or more layers of a dielectric material. 
     
     
         12 . A medium as defined in  claim 9  wherein the dielectric material is a dielectric polymeric material or is one of ZnS and MgF2. 
     
     
         13 . A medium as defined in  claim 4 , wherein the medium is composed of less than 15% taggent flakes. 
     
     
         14 . A medium as defined in  claim 13 , wherein some of the taggent flakes are each less than 500 nm thick less than 900μ 2  in area across a visible surface. 
     
     
         15 . A medium as defined in  claim 13 , wherein some of the taggent flakes are shaped flakes comprised of a metal layer having indicia thereon. 
     
     
         16 . A medium as defined in  claim 13 , wherein at least some of the taggent flakes comprise a central layer of Al and a coating on upper and lower surfaces of the central layer of ZnS, or a coating enveloping the Al central layer of ZnS. 
     
     
         17 . A medium as defined in  claim 1  disposed within a laser printer or copier cartridge. 
     
     
         18 . A medium as defined in  claim 4 , wherein the flakes are microstructured covert taggant flakes. 
     
     
         19 . A medium as defined in  claim 4  disposed in separate containers of toner for printing in a same printer and wherein at least some of the separate containers have different taggents than other of the containers wherein the different taggents are visually distinguishable under magnification. 
     
     
         20 . A medium as defined in  claim 1 , wherein the shaped flakes are magnetic for use in magneto-graphic printing. 
     
     
         21 . A kit comprising laser toner and optical effect flakes for combining to form laser toner having security features therein.