Light guides having enhanced light extraction
Assignee3M Innovative Properties Company
InventorsTzu-Chen Lee, David A. Ender, Guoping Mao, Jun-Ying Zhang, Jaime B. Willoughby
Life of this patent
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Abstract
Lightguides, devices incorporating lightguides, processes for making lightguides, and tools used to make lightguides are described. A lightguide includes light extractors arranged in a plurality of regions on a surface of the lightguide. The orientation of light extractors in each region is arranged to enhance uniformity and brightness across a surface of the lightguide and to provide enhanced defect hiding. The efficiency of the light extractors is controlled by the angle of a given light extractor face with respect to a light source illuminating the light guide.
Claims15
A tool for making a lightguide, comprising:
- a plurality of regions;
- and an array of prisms located within each region, each prism having a first base edge facing a front edge of the tool;
- the first base edge of a prism within a first region being non-parallel to the first base edge of a prism within a second region, wherein the tool is comprised of silicon, wherein at least one prism is comprised of a four-faceted pyramid, and the facets of the pyramid are formed at an angle corresponding to a crystalline structure of the silicon.
A method for fabricating a lightguide tool comprising:
- etching a number of pyramidal structures into a first region of a substrate, the structures oriented such that the base of each structure within the first region is oriented at a first angle with respect to a front edge of the lightguide tool;
- etching a number of pyramidal structures into a second region of a substrate, the structures oriented such that the base of each structure within the second region is oriented at a second angle with respect to the front edge of the lightguide tool different from the first angle, wherein the substrate is comprised of a plurality of crystalline wafers.
Dependencies are inferred from the claim text.