# US 2025/0146902 A1 · Oblique lighting system for inspection of end connectors of fiber optic cables by microscope > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0146902 A1 - Document ID: US20250146902A1 - Status: Published application - Kind: A1 - Application number: 18/504,540 - Filed: 2023-11-08 - Published: 2025-05-08 - Earliest claimed: 2023-11-08 - Assignees: Viavi Solutions Inc. - Applicants: Viavi Solutions Inc. - Inventors: Joshua Benjamin Julius PHILIPSON; Kevin CASSADY; Nicklos Joseph BULITKA; Christopher Russell WAGNER; Christian Richard COMTOIS-ARNALDO - Web page: https://patentgrep.com/patent/US20250146902A1 ## CPC - G01M 11/30: {Testing of optical devices, constituted by fibre optics or optical waveguides} - G02B 21/10: affording dark-field illumination (G02B21/14 {and G02B21/125} take precedence) - G02B 21/367: {providing an output produced by processing a plurality of individual source images, e.g. image tiling, montage, composite images, depth sectioning, image comparison} - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract Systems, methods, and devices for inspection, under a microscope, of end connectors of fiber optic cables are provided. In one aspect, a light ring including a circular array of light sources provides darkfield illumination to an end connector being inspected under a microscope. Each of the light sources may be lit in series and the resulting shadows may be used to identify dirt on the end connector, as well as to determine whether any dirt identified on the end connector can be cleaned off. In another aspect, a light ring combined with a redirection ring (e.g., a reflector and/or refractor ring) may provide darkfield illumination. In yet another aspect, a series of images may be captured and analyzed to automatically identify dirt on the end connector, as well as to determine whether any identified dirt can be cleaned off. ## Claims ### Claim 1 A system of oblique lighting, comprising: a light ring comprising a plurality of light sources disposed in a circular pattern to illuminate an end connector of a fiber optic cable for viewing under a microscope, wherein light from the plurality of light sources provides darkfield illumination to the end connector; an imager connected to the microscope to capture images of the end connector under darkfield illumination; and a controller to: control each of the plurality of light sources to light in a time sequence; control the imager to capture a series of images where each image corresponds to when one of the plurality of light sources is lit up; and analyze the captured series of images to identify surface particulates on the end connector. ### Claim 2 (depends on 1) The system of claim 1, wherein the controller is to further analyze the captured series of images to determine whether any identified surface particulates are cleanable. ### Claim 3 (depends on 2) The system of claim 2, wherein the controller is to further provide feedback at least one of identifying any identified surface particulates or identifying any identified surface particulates that are cleanable. ### Claim 4 (depends on 1) The system of claim 1, wherein the controller is to further analyze the captured series of images to identify at least one of a defect or an imperfection in the end connector. ### Claim 5 (depends on 1) The system of claim 1, wherein the controller is to further analyze the captured series of images to measure one or more dimensional features of the end connector. ### Claim 6 (depends on 1) The system of claim 1, wherein the plurality of light sources is mounted on the light ring such that the light from the plurality of light sources shines on the end connector with an angle of incidence (AOI) sufficient to produce darkfield illumination. ### Claim 7 (depends on 1) The system of claim 1, further comprising: a redirection ring disposed to receive light directly from the plurality of light sources disposed on the light ring and to redirect the light from the plurality of light sources onto the end connector with an angle of incidence (AOI) sufficient to provide darkfield illumination. ### Claim 8 (depends on 7) The system of claim 7, wherein the redirection ring comprises: a reflector ring comprising an inner reflective surface, wherein the inner reflective surface is disposed to receive light directly from the plurality of light sources and to reflect the light from the plurality of light sources onto the end connector with an AOI sufficient to provide darkfield illumination. ### Claim 9 (depends on 7) The system of claim 7, wherein the redirection ring comprises: a refractor ring comprising a refractive body, wherein the refractive body is disposed to receive light directly from the plurality of light sources and to refract the light from the plurality of light sources onto the end connector with an angle of incidence (AOI) sufficient to provide darkfield illumination. ### Claim 10 An oblique lighting system for inspection, under a microscope, of an end connector of a fiber optic cable, comprising: a light ring comprising a plurality of light sources disposed on a planar ring parallel to a plane of an objective lens of the microscope, wherein a center of the planar ring roughly coincides with a viewing axis of the microscope; and a redirection ring disposed to receive light directly from the plurality of light sources disposed on the light ring and to redirect the received light onto the end connector with an angle of incidence (AOI) sufficient to produce darkfield illumination. ### Claim 11 (depends on 10) The oblique lighting system of claim 10, wherein the redirection ring comprises: a reflector ring comprising an inner reflective surface, wherein the inner reflective surface is disposed to receive light directly from the plurality of light sources and to reflect the light from the plurality of light sources onto the end connector with an AOI sufficient to provide darkfield illumination. ### Claim 12 (depends on 10) The oblique lighting system of claim 10, wherein the redirection ring comprises: a refractor ring comprising a refractive body, wherein the refractive body is disposed to receive light directly from the plurality of light sources and to refract the light from the plurality of light sources onto the end connector with an angle of incidence (AOI) sufficient to provide darkfield illumination. ### Claim 13 (depends on 10) The oblique lighting system of claim 10, further comprising: an imager connected to the microscope to capture images of the end connector under darkfield illumination; and a controller to: control each of the plurality of light sources to light in a time sequence; control the imager to capture a series of images where each image corresponds to when one of the plurality of light sources is lit up; and analyze the captured series of images to identify at least one of a defect or an imperfection of the end connector. ### Claim 14 (depends on 13) The oblique lighting system of claim 13, wherein the controller is to further analyze the captured series of images to measure one or more dimensional features of the end connector. ### Claim 15 (depends on 14) The oblique lighting system of claim 14, wherein the controller is to further provide feedback at least one of identifying any identified defect or imperfection or indicating any measured one or more dimensional features of the end connector. ### Claim 16 A method for inspecting, under a microscope, an end connector of a fiber optic cable, comprising: controlling, by a controller, each of a plurality of light sources in a light ring to light separately in a time sequence, wherein each of the plurality of light sources in the light ring provides darkfield illumination to the end connector under the microscope; controlling, by the controller, an imager to capture a series of images where each image corresponds to when one of the plurality of light sources is lit up; analyzing, by the controller, the captured series of images to identify surface particulates on the end connector; and analyzing, by the controller, the captured series of images to determine whether any identified surface particulates on the end connector are cleanable. ### Claim 17 (depends on 16) The method of claim 16, further comprising: providing, by the controller, feedback at least one of identifying any identified surface particulates or identifying any identified surface particulates that are cleanable. ### Claim 18 (depends on 16) The method of claim 16, further comprising: analyzing, by the controller, the captured series of images to identify any defect or imperfection of the end connector. ### Claim 19 (depends on 16) The method of claim 16, further comprising: analyzing, by the controller, the captured series of images to identify any organic matter on the end connector, wherein organic matter comprises at least one of grease or oil. ### Claim 20 (depends on 16) The method of claim 16, further comprising: analyzing, by the controller, the captured series of images to measure one or more dimensional features of the end connector.