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:
Nov. 28, 2006
Filed:
Dec. 28, 2004
Robert J. Fleming, St. Paul, MN (US);
Christopher S. Lyons, St. Paul, MN (US);
Joseph M. Mcgrath, Lake Elmo, MN (US);
Jesus Ramos, Tucson, AZ (US);
Mark A. Roehrig, Stillwater, MN (US);
Clark I. Bright, Tucson, AZ (US);
Robert J. Fleming, St. Paul, MN (US);
Christopher S. Lyons, St. Paul, MN (US);
Joseph M. McGrath, Lake Elmo, MN (US);
Jesus Ramos, Tucson, AZ (US);
Mark A. Roehrig, Stillwater, MN (US);
Clark I. Bright, Tucson, AZ (US);
3M Innovative Properties Company, St. Paul, MN (US);
Abstract
Color shifting retroreflective articles can provide features such as decorative effects, evidence of tampering, security authentication or positional information. In some embodiments, the color shifting retroreflective article includes a layer of microspheres, and a reflective coating that is disposed in optical association with the layer of microspheres. The reflective coating includes a spacer layer disposed between a semitransparent first reflective layer and a second reflective layer. The first reflective layer includes a reflective layer disposed adjacent the layer of microspheres. At least one layer of the reflective coating includes a non-uniform thickness associated with each of a plurality of microspheres such that light incident on the article from a first direction is retroreflected at a first color and light incident on the article from a second direction is retroreflected at a second color visibly different from the first color.