Erasable Barcode

Abstract

The Erasable Barcode prevents the sale of products by invalidating the barcode. The invalidation can be based on shelf life, or improper temperature maintenance. The invalidation is also visible to humans so that the consumer knows if the exposure occurs after purchase. Activation brings liquid from the first reservoir in contact with the migration medium. The liquid progressively produces a change in color over time in the migration medium. When the liquid has crossed the migration medium, it will come in contact with the absorptive medium. The absorptive medium will then rapidly change color. The absorptive layer is the substrate for a machine readable barcode such that the color change renders the barcode unreadable

What is claimed is: 
     
         1 . An erasable barcode comprising:
 a reservoir;   an amount of liquid in the reservoir;   a rate controlled migration medium;   an absorptive medium;   a single machine readable barcode proximal to the absorptive medium;   the first reservoir passing the liquid to the migration medium wherein the liquid migrates across the migration medium and comes into contact with the absorptive medium, and the absorptive medium rapidly changes color in response to the contact rendering the barcode unreadable, and wherein the absorptive layer is a substrate upon which the barcode is formed.   
     
     
         2 . The erasable barcode according to  claim 1  with the migration limited by both a temperature threshold and specific duration of time. 
     
     
         3 . The erasable barcode according to  claim 1  with the migration limited by only a temperature threshold. 
     
     
         4 . The erasable barcode according to  claim 1  with the migration limited by only specific duration of time. 
     
     
         5 . The erasable barcode according to  claim 1  where the color of the machine readable barcode is similar to the color of the absorptive medium after the absorptive medium comes into contact with the liquid. 
     
     
         6 . The erasable barcode according to  claim 1  where as the machine readable barcode becomes unreadable a message appears. 
     
     
         7 . The erasable barcode according to  claim 1  where the liquid is substantially the same color as the machine readable barcode. 
     
     
         8 . The erasable barcode according to  claim 1  where the printable surface contains a first message placed proximal to the machine readable barcode so that when the liquid enters the absorptive medium and a transparent second message that is not readable by a human person so that when the liquid migrates across the migration medium and comes into contact with the absorptive medium, and the absorptive medium rapidly changes color in response to the contact rendering the barcode unreadable, the second message is rendered opaque by the liquid and the second message is revealed in such a manner that is readable by a human person that negates the meaning of the first message. 
     
     
         9 . The erasable barcode according to  claim 1  where the single barcode is not proximal to any other barcode.