| US 7,467,873 B2 | ||
| Privacy film | ||
| Graham M. Clarke, Woodbury, Minn. (US); Paul D. Graham, Woodbury, Minn. (US); Brent R. Hansen, New Richmond, Wis. (US); Travis B. Hoium, Moorhead, Minn. (US); and David F. Slama, Grant, Minn. (US) | ||
| Assigned to 3M Innovative Properties Company, St. Paul, Minn. (US) | ||
| Filed on Oct. 14, 2005, as Appl. No. 11/250,676. | ||
| Prior Publication US 2007/0087186 A1, Apr. 19, 2007 | ||
| Int. Cl. G02B 27/00 (2006.01) | ||
| U.S. Cl. 359—601 [428/29; 428/167; 428/916; 283/72; 283/901; 283/902] | 31 Claims |
| 1. A privacy film comprising
a light transmissive, polymeric base sheet comprising a first polymeric material, the base sheet having opposing first and
second surfaces, the second surface being substantially flat; and
a plurality of freestanding light directing elements comprising a second polymeric material, wherein each element has a base,
a height h, and a minor axis disposed along the height, wherein the elements protrude from the first surface of the base sheet,
and wherein each element is disposed such that the minor axis of one element is substantially parallel to the minor axis of
the next adjacent element and the base of one element is not joined with the base of the next adjacent element,
wherein the elements are disposed on the base sheet at a cant angle greater than about 40° and less than about 85° , the cant
angle being formed between the first surface of the base sheet and the minor axis of the element, and
wherein the privacy film is used with documents.
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