Patent ID: 11865808
Assignee: 3M INNOVATIVE PROPERTIES COMPANY
Field: Other special machines (Mechanical engineering)
Classification: CPC B | IPC B

Claim 14:
15. A curved optical film comprising a plurality of polymeric layers shaped along orthogonal first and second directions such that:
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 at least 90 degrees, the optical film having a maximum projected area in the reference plane; and
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,, wherein each location across at least 90% of a total area of the optical film has a reflectance greater than about 80% and a transmittance less than about 2% for normally incident light having a same predetermined wavelength and a same first polarization state, and, wherein the first curve passes through a center of the optical film, the optical film has a first long wavelength band edge at a first location along the first curve and a second long wavelength band edge at a second location along the first curve, the second location separated from the first location by a distance along the first curve of at least 0.7 times a radius R1 of the best-fit first circular arc, a distance from the center of the optical film to the first location along the first curve being no more than 0.2 R1, a distance from the second location to an edge of the optical film along the first curve being no more than 0.2 R1, the first and second long wavelength band edges differing by no more than 5%.