Optical polarizing films with designed color shifts
Assignee3M Innovative Properties Company
InventorsTimothy Hebrink, Laurence Gilbert, James Jonza, Andrew Ruff
Life of this patent
Estimating the term…
Abstract
Multilayer films are provided that exhibit a colored appearance when viewed at an oblique angle as a result of one or more reflection bands in the visible region of the spectrum. The films however provide no substantial reflection bands in either the visible or near infrared regions for light normally incident on the film. The films can be made to shift from clear at normal incidence to an arbitrary designed color at an oblique angle without necessarily becoming cyan.
Claims24
An optical film, comprising a plurality of optical layers adapted to provide a reflection band covering a portion of the visible spectrum at an oblique angle such that the optical film appears colored at such oblique angle, and wherein the plurality of layers provide substantially no reflection bands for normally incident light.
An optical film, comprising a plurality of layers that form a plurality of optical repeat units, at least some of the optical repeat units having optical thicknesses equal to half of a wavelength of visible light, and wherein the optical film has a clear appearance at normal incidence.
An optical film whose transmitted appearance changes from substantially clear to a first color over an angular range of observation angles, and where the optical film does not appear cyan over such angular range.
Dependencies are inferred from the claim text.