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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 at least orthogonal first and second directions so that a first ratio of a first maximum sag to a corresponding first diameter along the first direction is at least 0.1, and a second ratio of a second maximum sag to a corresponding second diameter along the second direction is at least 0.05, 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 a 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 at least orthogonal first and second directions such that a first ratio of a first maximum sag to a corresponding first diameter along the first direction is at least about 0.1, and a second ratio of a second maximum sag to a corresponding second diameter along the second direction is at least about 0.05, wherein for normally incident light having a predetermined wavelength, each location over at least 80% of a 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.
An 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 optical film has a first thickness distribution along the first curve that is substantially symmetric under reflection about the second plane and a second thickness distribution along the second curve that is substantially symmetric under reflection about the first plane, the first and second thickness distributions being different.
Dependencies are inferred from the claim text.