Non-orthogonal cube corner elements and arrays thereof made by end milling
Assignee3M Innovative Properties Company
InventorsNelson D. Sewall, Christopher S. Grinde, Todd A. Ballen, Kenneth L. Smith
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Abstract
A new technique for making cube corner elements that involves end milling is used in the fabrication of cube corner elements having non-orthogonal dihedral angles and dihedral angle errors, and arrays of such cube corner elements. A given optical face of a cube corner element may be a compound face with two constituent faces. In some cases, the constituent faces may be parallel and coplanar such that a given dihedral angle error pertains to the entire optical face, while in other cases, the two constituent faces may not be parallel, and may be associated with different dihedral angle errors.
Claims7
An article comprising a cube corner element defined in a structured surface, the structured surface extending along a reference plane, the cube corner element including a first rounded edge that is inclined relative to the reference plane, the cube corner element also including a first, second, and third optical face, wherein at least part of the first optical face deviates from orthogonality relative to at least part of the second optical face by a first angle error whose magnitude is at least 1 minute of arc but no more than 2 degrees.
Dependencies are inferred from the claim text.