US Patent Issued to 3M Innovative Properties on March 18 for "Film stacks for thin circular polarizers" (Minnesota Inventors)

ALEXANDRIA, Va., March 19 -- United States Patent no. 12,253,701, issued on March 18, was assigned to 3M Innovative Properties Co. (St. Paul, Minn.).

"Film stacks for thin circular polarizers" was invented by Adam D. Haag (Woodbury, Minn.), Michael A. Johnson (Stillwater, Minn.), Michelle L. Toy (North St. Paul, Minn.), Brianna N. Wheeler (Bloomington, Minn.) and David T. Yust (Woodbury, Minn.).

According to the abstract* released by the U.S. Patent & Trademark Office: "A film stack includes co-stretched first and second layers. The first layer is stained with iodine and has a glass transition temperature of at least 5deg C. greater than a glass transition temperature of the second layer. The second layer has in-plane birefringence of les...