The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 19, 1985
Filed:
Sep. 15, 1982
Zvi Weinberger, Jerusalem, IL;
Teletoken Ltd., Holon, IL;
Abstract
An optically-readable value card for use in a vending system for vending goods or services includes a plurality of heat-sensitive optically-readable value elements each of which, upon heating to a first temperature above ambient, changes its color in a reversible manner, but upon heating to a second temperature above ambient and higher than the first temperature, changes to a second color in an irreversible manner. Each of the value elements is in the form of a light window having a layer of a thermochromic material which changes its color in a reversible manner when heated to the first temperature, and a layer of a thermographic material which changes its color in an irreversible manner when heated to the second temperature.