Vinyl surfaces for biometric print tir prisms

Abstract

Molded vinyl sheets with optical quality surfaces and methods for making the same. The vinyl sheets are made by molding liquid vinyl in a mold. In embodiments, the mold forms parallel optical quality flat surfaces. In one embodiment, a stiffening plastic is molded in the middle of the vinyl sheet between the parallel optical quality flat surfaces. In another embodiment, the mold forms one optical quality flat surface while the surface parallel to the optical quality flat surface is bonded to a prism.

1 . A total internal reflective (TIR) platen for a biometric imaging device, comprising: 
 a first layer of vinyl compound having an optical quality surface;    a second layer of vinyl compound having an optical quality surface;    a layer of stiff plastic embedded between the first layer of vinyl compound and the second layer of vinyl compound,    wherein the optical quality surface of the first layer of vinyl compound provides for a total internal reflective platen surface and the optical quality surface of the second layer of vinyl compound provides for making optical contact with a prism.    
   
   
       2 . The TIR platen of  claim 1 , wherein the optical quality surface of the second layer of vinyl compound is attached to the prism.  
   
   
       3 . The TIR platen of  claim 1 , wherein the optical quality surface of the second layer of vinyl compound is integrally molded to the prism.  
   
   
       4 . The TIR platen of  claim 1 , further comprising: 
 a first binder layer positioned between the first layer of vinyl and the layer of stiff plastic, wherein the first layer of vinyl is bound to the layer of stiff plastic; and    a second binder layer positioned between the second layer of vinyl and the layer of stiff plastic, wherein the second layer of vinyl is bound to the layer of stiff plastic.    
   
   
       5 . The TIR platen of  claim 1 , wherein the layer of stiff plastic comprises at least one of: polycarbonate, acrylic, CR39, or styrene.  
   
   
       6 . A method for making a vinyl sheet, comprising the steps of: 
 (1) preparing a liquid vinyl compound;    (2) out gassing said liquid vinyl compound;    (3) pouring said liquid vinyl compound into one or more cavity molds; and    (4) curing said liquid vinyl compound to generate said vinyl sheet.    
   
   
       7 . The method of  claim 6 , further comprising the step of removing said vinyl sheet from said mold.  
   
   
       8 . The method of  claim 7 , further comprising the step of cutting said vinyl sheet to defined dimensions for a defined application.  
   
   
       9 . The method of  claim 6 , wherein step (1) comprises the steps of: 
 (a) coating a surface of a prism with a binder; and    (b) curing the binder, wherein said vinyl sheet will be integrally molded to the prism after step (4) is completed.    
   
   
       10 . The method of  claim 9 , wherein step (a) further comprises the step of coating said binder with a vinyl sealer.  
   
   
       11 . The method of  claim 6 , wherein step (1) comprises the steps of: 
 (a) applying a binder to a stiffening material;    (b) curing said stiffening material;    (c) placing said stiffening material in a tension device between said one or more cavity molds; and    (d) tensioning said stiffening material.    
   
   
       12 . The method of  claim 6 , wherein step (1) comprises the step of diluting liquid vinyl with a vinyl thinner solution.  
   
   
       13 . A vinyl sheet, comprising: 
 a first layer of vinyl compound having an optical quality surface;    a second layer of vinyl compound having an optical quality surface;    a layer of stiff plastic embedded between the first layer of vinyl and the second layer of vinyl,    wherein the optical quality surface of the first layer and the optical quality surface of the second layer each face away from the layer of stiff plastic; and    wherein the optical quality surface of the second layer provides for a total internal reflective platen surface.    
   
   
       14 . The vinyl sheet of  claim 13 , wherein the optical quality surface of the first layer of vinyl compound makes optical contact with a prism.  
   
   
       15 . The vinyl sheet of  claim 13 , wherein the optical quality surface of the first layer of vinyl compound is attached to the prism.  
   
   
       16 . The vinyl sheet of  claim 13 , wherein the optical quality surface of the second layer of vinyl compound forms a total internal reflective platen surface.  
   
   
       17 . The vinyl sheet of  claim 13 , further comprising: 
 a first binder layer positioned between the first layer of vinyl and the layer of stiff plastic, wherein the first layer of vinyl is bound to the layer of stiff plastic; and    a second binder layer positioned between the second layer of vinyl and the layer of stiff plastic, wherein the second layer of vinyl is bound to the layer of stiff plastic.    
   
   
       18 . The vinyl sheet of  claim 13 , wherein the optical quality surface of the first layer of vinyl is integrally molded onto a prism.  
   
   
       19 . The vinyl sheet of  claim 13 , wherein the layer of stiff plastic comprises at least one of: polycarbonate, acrylic, CR39, or styrene.