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

Claim 4:
5. The optical film of claim 1, wherein the first curve passes through a center of the optical film, the optical film has a first thickness at first location along the first curve and a second thickness 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 0.8 times a radius of curvature R of the first curve at the center of the optical film, a distance from the center of the optical film to the first location along the first curve being no more than 0.2 R, a distance from the second location to an edge of the optical film along the first curve being no more than 0.2 R, the first and second thicknesses differing by no more than 5%.