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:
Sep. 22, 1992
Filed:
Oct. 18, 1991
David Wilson, Mississauga, CA;
Golden Valley Microwave Foods Inc., Edina, MN (US);
Abstract
A selectively demetallized metal film is provided in which the metal film has different amounts of metal removed in different areas to provide a film having a graduated optical density from one area to another. The amount of metal present in the film can vary gradually and continuously or in stages resulting in a series of bands or patches. Each portion of the film appears uniform, homogeneous and uninterrupted to the unaided eye. The product is produced by providing a substrate such as plastic film having a thin semiconductive metal film coated thereon. Different amounts of the metal are removed from the film in different areas, preferably by exposing the metal film in different areas to different amounts of an etchant which can be provided in the form of minute droplets of one size in one area and of a different size in a different area. The etchant can be applied by halftone printing as variably sized dots on uniformly fixed centers with larger dots of etchant applied in some areas than in others to remove a greater amount of the metal.