US 12,436,062 B2
Techniques for examination of light optical elements
Eitan Ronen, Rechovot (IL)
Assigned to Lumus Ltd., Ness Ziona (IL)
Appl. No. 18/998,074
Filed by Lumus Ltd., Ness Ziona (IL)
PCT Filed Jul. 31, 2023, PCT No. PCT/IB2023/057754
§ 371(c)(1), (2) Date Jan. 23, 2025,
PCT Pub. No. WO2024/028746, PCT Pub. Date Feb. 8, 2024.
Claims priority of provisional application 63/393,994, filed on Aug. 1, 2022.
Prior Publication US 2025/0264369 A1, Aug. 21, 2025
Int. Cl. G01M 11/02 (2006.01)
CPC G01M 11/0207 (2013.01) 8 Claims
OG exemplary drawing
 
1. A system for measuring parallelism and homogeneity of refractive index of facets of a lightguide optical element (LOE), the LOE including a light-transmitting substrate having first and second major surfaces parallel to each other such that light coupled into the light-transmitting substrate is trapped between the first and second major surfaces by total internal reflection and the facets configured to couple the light out of the substrate, the system comprising:
a processing unit configured to control at least one of a first slit and a second slit such that the first slit is disposed optically between a projector configured to emit light corresponding to an image and the first major surface, the first slit disposed such that light from the projector travels through the first slit to the first major surface and to a first facet of the facets and such that the second slit is disposed optically between the second major surface and a detector, the second slit disposed as to block light transmitted by the first facet and such that light reflected by the first facet and a second facet, from the facets, travels from the second facet to the second major surface and through the second slit to the detector;
the processing unit configured to deduce the parallelism between the first facet and the second facet based on a shift of the image as detected by the detector relative to light transmitted normal to the first and second major surfaces through a portion of the substrate not including a facet from the facets;
the processing unit configured to control the at least one of the first slit and the second slit such that the second slit is disposed optically between the second major surface and the detector such that light from the projector travels through the first slit to the first major surface and to the first facet and light transmitted through the first facet travels from the first facet to the second major surface and through the second slit to the detector; and
the processing unit configured to determine the homogeneity or deviation in refractive index between surfaces of the first facet based on the light transmitted through the first facet, as detected by the detector, relative to light transmitted normal to the first and second major surfaces through a portion of the substrate not including a facet from the facets.