High efficiency optical devices
Assignee3M Innovative Properties Company
InventorsMichael F. Weber, David L. Wortman, Andrew J. Ouderkirk, Sanford Cobb, Jr.
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Abstract
Optical devices such as light pipes which incorporate multilayer optical films in which the refractive indices of two adjacent layers in the thickness direction are substantially matched or are small relative to the difference in refractive indices of said two adjacent layers in an given in-plane direction which is at least 0.05.
Claims34
An optical device comprising a body having at least two opposing optical surfaces, at least a portion of each of the opposing optical surfaces comprising a film including
- a first layer comprising a first polymeric material;
- and
- a second layer contiguous to the first layer, the second layer comprising a second polymeric material;
- wherein the absolute value of the difference in indices of refraction between the first and second layers is .DELTA.x, .DELTA.y, and .DELTA.z, respectively, for light polarized along first, second, and third mutually orthogonal axes, the third axis being orthogonal to the plane of the film, and further wherein .DELTA.x is greater than about 0.05 and .DELTA.z is less than about 0.05.
An optical device comprising a body having at least two opposing optical surfaces, at least a portion of each of the opposing optical surfaces comprising a film including
- a first layer comprising a first polymeric material;
- and
- a second layer contiguous to the first layer, the second layer comprising a second polymeric material;
- wherein the absolute value of the difference in index of refraction between the first and second polymeric material is .DELTA.x, .DELTA.y, and .DELTA.z, respectively, for light polarized along first, second, and third mutually orthogonal axes, wherein the third axis is orthogonal to the plane of the film, wherein .DELTA.z is less than 0.5 k, where k is the larger of .DELTA.x and .DELTA.y, and wherein k is at least about 0.05.
Dependencies are inferred from the claim text.