Retroreflector with controlled divergence made by the method of localized substrate stress
AssigneeAvery Dennison Corporation
InventorsDennis I. Couzin, Steven R. Chapman, Kejian Huang
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Abstract
A cube corner array with minute modifications of the dihedral angles of some of the cube corners is produced by introducing a stress or change via the opposite side of the substrate. The array having aberrated elements can be replicated for use in the manufacture of a tool, and the tool can be used in the manufacture of retroreflective products of broader divergence.
Claims20
A method of producing an array of micro-optical elements, said method comprising the steps of:
- providing a substrate having an array of micro-optical elements formed thereon, and
- controlled working at one or more localized regions on a surface of the substrate;
- wherein said controlled working step is performed so as to aberrate one or more of the micro-optical elements while preserving total retroreflectance to thereby produce a worked array of micro-optical elements having divergence over a desired range and having a total retroreflectance that is at least 90% of the retroreflectance of the array before said controlled working step.
An article comprising a substrate for making an array of retroreflective elements;
- the substrate having an array of micro-optical elements formed thereon;
- the array of micro-optical elements including at least one aberrated micro-optical element and a plurality of non-aberrated micro-optical elements;
- the substrate having a surface having localized regions which have been controlled worked to form the aberrated micro-optical elements;
- the array of micro-optical elements having divergence over a desired range and having a total retroreflectance that is at least 90% of the retroreflectance of the array if the localized regions had not been controlled worked.
A method of making a retroreflective product, said method comprising the steps of:
- providing a substrate having an array of micro-optical elements formed thereon,
- controlled working at one or more localized regions on a surface of the substrate, said controlled working step being performed so as to aberrate one or more of the micro-optical elements while preserving total retroreflectance to thereby produce a worked array of micro-optical elements having divergence over a desired range and having a total retroreflectance that is at least 90% of the retroreflectance of the array before said controlled working step;
- assembling the substrate, and/or copies of the substrate into a tool;
- and
- using the tool to manufacture the retroreflective product.
Dependencies are inferred from the claim text.