US 11,655,957 B2
Microstructures for transforming light having Lambertian distribution into batwing distributions
Bing Shen, Cary, NC (US); Ken G. Purchase, Morrisville, NC (US); Thomas A. Rinehart, Durham, NC (US); and John W. Wilson, Durham, NC (US)
Assigned to Brightview Technologies, Inc., Durham, NC (US)
Filed by Brightview Technologies, Inc., Durham, NC (US)
Filed on Jun. 16, 2022, as Appl. No. 17/841,713.
Application 17/841,713 is a continuation of application No. 16/962,155, granted, now 11,391,437, previously published as PCT/US2019/015600, filed on Jan. 29, 2019.
Claims priority of provisional application 62/623,894, filed on Jan. 30, 2018.
Prior Publication US 2022/0307672 A1, Sep. 29, 2022
Int. Cl. F21V 5/00 (2018.01); F21Y 115/10 (2016.01)
CPC F21V 5/005 (2013.01) [F21Y 2115/10 (2016.08)] 25 Claims
OG exemplary drawing
 
1. A light transmissive substrate for transforming a Lambertian light distribution into a batwing light distribution, the light transmissive substrate comprising:
a first surface comprising a plurality of microstructures; and
a second surface on a side of the substrate opposite the first surface, wherein each of the plurality of microstructures has a shape of a pyramid with a roof angle of between about 70° and about 95° and extending in a direction away from the second surface,
wherein the substrate is configured to receive light in a Lambertian distribution from a light source at the first surface and transform the light into a three-dimensional batwing distribution exiting the second surface, the three-dimensional batwing distribution having peak intensities at angles ranging from ±30° to about ±60° from X and Y axes and a desired intensity at nadir that is less than at least one of peak intensities and, wherein a refractive index of the microstructures and the roof angle are chosen to provide a desired shape of the three-dimensional batwing distribution and the desired intensity at nadir.