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:
Apr. 07, 2015
Filed:
Feb. 13, 2009
Kenneth A. Epstein, St. Paul, MN (US);
Stephen J. Etzkorn, Woodbury, MN (US);
Eric W. Nelson, Stillwater, MN (US);
Mark D. Gehisen, Eagan, MN (US);
Brian G. Koethe, Cottage Grove, MN (US);
Kenneth A. Epstein, St. Paul, MN (US);
Stephen J. Etzkorn, Woodbury, MN (US);
Eric W. Nelson, Stillwater, MN (US);
Mark D. Gehisen, Eagan, MN (US);
Brian G. Koethe, Cottage Grove, MN (US);
3M Innovative Properties Company, St. Paul, MN (US);
Abstract
An optical device has a first film () that has a first side and a second side. When illuminated by light () at the first side, the first film is characterized by a first fraction of broadly diffused transmitted light () and a second fraction of narrowly diffused transmitted light (). A second film () is disposed to the second side of the first film. The second film has at least one free surface that diverts light. In some embodiments, the first film has a diffuse scattering optical density between 0.5 and 3. The device finds use in spreading and making light uniform in a backlight in a display such as a liquid crystal display.