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. 24, 2002
Filed:
Sep. 14, 2000
Michael C. Lea, Bracknell, GB;
Charles A. Marttila, Shoreview, MN (US);
3M Innovative Properties Company, St. Paul, MN (US);
Abstract
An optical sheet ( ) for spreading light has a substantially smooth surface ( ), and a structured surface ( ) comprising an array of prisms ( ). A beam of light that is to be spread is directed through the film from the smooth surface. Some of the prisms (termed “refraction prisms”) deviate normally-incident light only by refraction at a prism facet as the light leaves the film while others (termed “reflection prisms”) deviates normally-incident light by total internal reflection within the prism before the light leaves the film. There are a plurality of reflection prisms ( ) selected to deviate normally-incident light through different angles and a plurality of refraction prisms ( ) selected to deviate the normally-incident light through different angles, and they are arranged, preferably in a non-ordered manner, so that successive reflection prisms are separated by at least one refraction prism. In alternative embodiments, the structured surface comprises a non-ordered arrangement of a plurality of reflection prisms selected to deviate normally-incident light through different angles, or a non-ordered arrangement of a plurality of refraction prisms selected to deviate normally-incident light through different angles.