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:
Jan. 18, 2005
Filed:
Jun. 11, 2002
Nelson D. Sewall, Forest Lake, MN (US);
Kenneth L. Smith, White Bear Lake, MN (US);
David W. Meitz, St. Paul, MN (US);
Madeleine B. Fleming, Lake Elmo, MN (US);
John C. Nelson, The Sea Ranch, CA (US);
Nelson D. Sewall, Forest Lake, MN (US);
Kenneth L. Smith, White Bear Lake, MN (US);
David W. Meitz, St. Paul, MN (US);
Madeleine B. Fleming, Lake Elmo, MN (US);
John C. Nelson, The Sea Ranch, CA (US);
3M Innovative Properties Company, St. Paul, MN (US);
Abstract
The invention relates to methods of making a master and replicas thereof including tooling and retroreflective sheeting. The invention further relates to the corresponding master, tooling and in particular retroreflective sheeting. The method comprises forming V-shaped grooves in a substrate (e.g. metal plate) wherein the intersections of three grooves form cube-corner elements. The cube-corner elements are substantially the same size throughout the array. The master as well as corresponding tooling and sheeting preferably have an average groove spacing within the range of about 0.0005 inches (0.0127 mm) to about 0.007 inches (0.1778 mm) throughout the array and more preferably an average groove spacing of less than about 0.004 inches (0.1016 mm).