# US 2019/0317023 A1 · A method and system for detecting a diamond signature > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0317023 A1 - Document ID: US20190317023A1 - Status: Published application - Kind: A1 - Application number: 16/344,179 - Filed: 2017-10-24 - Published: 2019-10-17 - Earliest claimed: 2016-10-24 - Assignees: Tomra Sorting GmbH - Applicants: Tomra Sorting GmbH - Inventors: Geoffrey Harold MADDERSON; Markus DEHLER - Web page: https://patentgrep.com/patent/US20190317023A1 ## CPC - G01N 21/87: Investigating jewels (G01N21/88 takes precedence) - B07C 5/342: according to optical properties, e.g. colour {(according to radiation transmittivity B07C5/3416)} - B07C 5/3425: {of granular material, e.g. ore particles, grain (investigation moving fluids or granular solids using optical means G01N21/85)} - G01N 21/359: using near infrared light - G01N 21/85: Investigating moving fluids or granular solids - G01N 33/389: {Precious stones; Pearls} - B07C 2501/0018: Sorting the articles during free fall - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - B07C: POSTAL SORTING; SORTING INDIVIDUAL ARTICLES, OR BULK MATERIAL FIT TO BE SORTED PIECE-MEAL, e.g. BY PICKING (specially adapted for a specific purpose covered by another class, see the relevant place, e.g. A43D33/06, B23Q7/12) ## Abstract A method for identifying the presence of partly liberated diamonds in a material stream. The method can include illuminating a material with a multi-wavelength beam including at least one monochromatic SWIR laser beam, and at least one IR scatter-/anti-scatter laser beam, capturing a portion of the at least one monochromatic SWIR laser beam after the monochromatic SWIR laser beam has been reflected and/or scattered by the material, producing a SWIR signal based on the captured portion of the at least one monochromatic SWIR laser beam, and capturing a first portion of the at least one IR scatter-/anti-scatter laser beam after the at least one IR scatter-/anti-scatter laser beam has been scattered and optionally reflected by the material. ## Claims ### Claim 1 A method for identifying the presence of partly liberated diamonds in a material stream, said method comprising the steps of: illuminating a material with a multi-wavelength beam comprising at least one monochromatic SWIR laser beam, and at least one IR scatter-/anti-scatter laser beam, capturing a portion of said at least one monochromatic SWIR laser beam after said monochromatic SWIR laser beam has been reflected and/or scattered by the material, producing a SWIR signal based on the captured portion of said at least one monochromatic SWIR laser beam, capturing a first portion of said at least one IR scatter-/anti-scatter laser beam after said at least one IR scatter-/anti-scatter laser beam has been scattered and optionally reflected by the material, separating and thereafter capturing a reflected portion of said at least one IR scatter-/anti-scatter laser beam after said at least one IR scatter-/anti-scatter laser beam has been reflected by the material from a portion of said at least one IR scatter-/anti-scatter laser beam after said at least one IR scatter-/anti-scatter laser beam has been scattered by the material, producing an IR scatter signal based on said captured first portion of said at least one IR scatter-/anti-scatter laser beam, producing an IR reflection signal based on said captured reflected portion of said at least one IR scatter-/anti-scatter laser beam, classifying the material as comprising diamond based on the presence of a diamond signature in the combination of the SWIR signal, the IR reflection signal and the IR scatter signal. ### Claim 2 (depends on 1) The method of claim 1, further comprising the step of separating a first portion of said at least one IR scatter-/anti-scatter laser beam after said at least one IR scatter-/anti-scatter laser beam has been scattered by the material from a portion of said at least one IR scatter-/anti-scatter laser beam after said at least one IR scatter-/anti-scatter laser beam has been reflected by the material, and thereafter capturing said first portion of said at least one IR scatter-/anti-scatter laser beam. ### Claim 3 (depends on 1) The method of claim 1, wherein said at least one IR scatter-/anti-scatter laser beam is at least one monochromatic IR scatter-/anti-scatter laser beam. ### Claim 4 (depends on 1) The method of claim 1, further comprising the step of filtering out light having the same polarization as the incident beam, so that only cross-polarized light is captured. ### Claim 5 (depends on 1) The method of claim 1, wherein the step of separating a reflected portion of said IR scatter-/anti-scatter laser beam is done by optically filtering scattered light from reflected light. ### Claim 6 (depends on 1) The method of claim 1, further comprising the step of splitting said IR scatter-/anti-scatter laser beam. ### Claim 7 (depends on 1) The method of claim 1, further comprising the step of normalizing the SWIR signal and the IR scatter signal by dividing each by the IR reflection signal. ### Claim 8 (depends on 1) The method of claim 1, further comprising the step of scanning said multi-wavelength beam across said material stream. ### Claim 9 (depends on 1) The method of claim 1, wherein the material stream comprises at least one rock particle having a partly liberated diamond. ### Claim 10 (depends on 7) The method of claim 7, further comprising forming a two-dimensional space using the normalized SWIR signal and the normalized IR scatter signal to represent the material. ### Claim 11 (depends on 10) The method of claim 10, wherein the two-dimensional space represents multiple rock particles. ### Claim 12 (depends on 10) The method of claim 10, further comprising classifying pixels within the two-dimensional space as diamond or other material classes. ### Claim 13 (depends on 1) The method of claim 1, for use in a sorting process, further comprising ejecting objects comprising material classified as diamond from a transportation direction of said material stream. ### Claim 14 (depends on 1) A computer readable medium containing program instructions which when executed by a processor cause the processor to perform the method of claim 1.