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Assignee3M Innovative Properties Company
InventorsRobert M. Jennings, William T. Fay, Jo A. Etter, Arthur L. Kotz, David J. W. Aastuen
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An optical film includes a plurality of polymeric layers shaped along orthogonal first and second directions. A first curve being an intersection of the optical film with a first plane orthogonal to the second direction and to a reference plane has a best-fit first circular arc subtending a first angle at a center of curvature of the first circular arc of greater than 180 degrees where the optical film has a maximum projected area in the reference plane. A second curve being an intersection of the optical film with a second plane orthogonal to the first direction and to the reference plane has a best-fit second circular arc subtending a second angle at a center of curvature of the second circular arc of at least 30 degrees. Reflectance and transmittance of the optical film are described.
A curved reflective polarizer comprising a plurality of polymeric layers shaped along orthogonal first and second directions such that a total curvature of the reflective polarizer is at least 0.25, the total curvature being a surface integral of a Gaussian curvature of the reflective polarizer over a total area of the reflective polarizer, wherein for normally incident light in a predetermined wavelength range, each location on the reflective polarizer has a maximum average reflectance greater than about 80% and a corresponding minimum average transmittance less than about 2% for a block polarization state, and a maximum average transmittance greater than about 80% for an orthogonal pass polarization state, wherein each location in a region of the reflective polarizer having an area of at least 80% of the total area of the reflective polarizer has a contrast ratio being the maximum average transmittance divided by the minimum average transmittance of at least 500.
A curved reflective polarizer comprising a plurality of polymeric layers shaped along orthogonal first and second directions such that a total curvature of the reflective polarizer is at least 0.25, the total curvature being a surface integral of a Gaussian curvature of the reflective polarizer over a total area of the reflective polarizer, wherein for normally incident light having a predetermined wavelength, each location over at least 80% of the total area of the reflective polarizer has a maximum reflectance greater than about 80% and a corresponding minimum transmittance less than about 0.2% for a block polarization state, and a maximum transmittance greater than about 80% for an orthogonal pass polarization state.
A curved optical film comprising a plurality of polymeric layers, each location across at least 90% of a total area of the optical film having a reflectance greater than about 80% and a transmittance less than about 5% for normally incident light having a same predetermined wavelength and a same first polarization state, wherein for orthogonal first and second planes intersecting the optical film along respective first and second curves, the first and second curves intersecting each other at a center location of the optical film, the optical film has a thickness that decreases from the center location to a first edge location of the optical film along the first curve and that increases from the center location to a second edge location along the second curve.
Dependencies are inferred from the claim text.