# US 11,992,263 B2 · Hair cutting device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,992,263 B2 - Document ID: US11992263B2 - Status: Granted - Kind: B2 - Application number: 17/831,701 - Filed: 2022-06-03 - Published: 2022-09-15 - Granted: 2024-05-28 - Earliest claimed: 2015-12-22 - Assignees: Koninklijke Philips N.V. - Applicants: Koninklijke Philips N.V. - Inventors: Yannyk Parulian Julian Bourquin; Rieko Verhagen; Bastiaan Wilhelmus Maria Moeskops; Kiran Kumar Thumma; Joseph Petrus Henricus Ter Borch; Mark Thomas Johnson; Arnoldus Johannes Martinus Jozeph Ras; Gerhardus Wilhelmus Lucassen; Martinus Bernardus van der Mark - Web page: https://patentgrep.com/patent/US11992263B2 ## CPC - A61B 18/203: {applying laser energy to the outside of the body} - A61B 2018/00476: {Hair follicles} - A61B 2018/202: {Laser enclosed in a hand-piece} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A hair cutting device for cutting hair on a body of a subject includes a light source for generating laser light at one or more specific wavelengths corresponding to wavelengths absorbed by one or more chromophores in hair; and a cutting element that has an optical waveguide that is coupled to the light source to receive laser light. A portion of a side wall of the optical waveguide forms a cutting face for contacting hair where, at least at the cutting face, the optical waveguide has a refractive index that is equal to or lower than the refractive index of hair and higher than the refractive index of skin. ## Claims ### Claim 1 A hair cutting device for cutting hair on a body of a subject, the hair cutting device comprising: a light source for generating laser light at one or more specific wavelengths corresponding to wavelengths absorbed by one or more chromophores in hair; and a cutting element that comprises an optical waveguide that is coupled to the light source to receive laser light, wherein a portion of a side wall of the optical waveguide forms a cutting face for contacting hair, and wherein the optical waveguide at the cutting face has a refractive index in a range of 1.48-1.56. ### Claim 2 (depends on 1) The hair cutting device as claimed in claim 1, wherein the refractive index of the optical waveguide at the cutting face is equal to or higher than 1.50. ### Claim 3 (depends on 1) The hair cutting device as claimed in claim 1, wherein the refractive index of the optical waveguide at the cutting face is equal to or higher than 1.51. ### Claim 4 (depends on 1) The hair cutting device as claimed in claim 1, wherein the refractive index of the optical waveguide at the cutting face is equal to or higher than 1.52. ### Claim 5 (depends on 1) The hair cutting device as claimed in claim 1, wherein the refractive index of the optical waveguide at the cutting face is equal to or higher than 1.53. ### Claim 6 (depends on 1) The hair cutting device as claimed in claim 1, wherein the refractive index of the optical waveguide at the cutting face is equal to or higher than 1.54. ### Claim 7 (depends on 1) The hair cutting device as claimed in claim 1, wherein the refractive index of the optical waveguide at the cutting face is equal to or lower than 1.55. ### Claim 8 (depends on 1) The hair cutting device as claimed in claim 1, wherein the refractive index of the optical waveguide at the cutting face is equal to or lower than 1.54. ### Claim 9 (depends on 1) The hair cutting device as claimed in claim 1, wherein the refractive index of the optical waveguide at the cutting face is in the range 1.51-1.55. ### Claim 10 (depends on 1) The hair cutting device as claimed in claim 1, wherein the refractive index of the optical waveguide at the cutting face is in the range 1.53-1.54. ### Claim 11 (depends on 1) The hair cutting device as claimed in claim 1, wherein the optical waveguide is composed of or comprises silica, fluoride glass, phosphate glass, chalcogenide glass, and/or crown glass. ### Claim 12 (depends on 1) The hair cutting device as claimed in claim 1, wherein the optical waveguide comprises a core and a cladding surrounding the core, wherein the cutting face is a portion of the side wall of the cladding. ### Claim 13 (depends on 12) The hair cutting device as claimed in claim 12, wherein the refractive index of the core is lower than or equal to the refractive index of the hair and higher than the refractive index of the skin, and wherein the refractive index of the cladding is lower than the refractive index of the core. ### Claim 14 (depends on 12) The hair cutting device as claimed in claim 12, wherein the cutting face comprises a portion of the cladding that is thinner than the cladding on other portions of the optical waveguide. ### Claim 15 (depends on 12) The hair cutting device as claimed in claim 12, wherein the optical waveguide is a D-shape optical waveguide or a polished optical waveguide. ### Claim 16 (depends on 1) The hair cutting device as claimed in claim 1, wherein the optical waveguide comprises a core and cladding that partially covers the core, wherein the cutting face comprises the portion of the core that is not covered by the cladding. ### Claim 17 (depends on 1) The hair cutting device as claimed in claim 1, wherein the refractive index of the optical waveguide decreases with increasing distance from an optical axis of the optical waveguide, wherein the cutting face is a shorter distance from the optical axis than other portions of the optical waveguide. ### Claim 18 (depends on 1) The hair cutting device as claimed in claim 1, wherein the optical waveguide is an optical fibre. ### Claim 19 A hair cutting device for cutting hair on a body of a subject, the hair cutting device comprising: a light source for generating laser light at one or more specific wavelengths corresponding to wavelengths absorbed by one or more chromophores in hair; and a cutting element that comprises an optical waveguide that is coupled to the light source to receive laser light, wherein the optical waveguide comprises a core and a cladding surrounding the core, wherein: a refractive index of the cladding is lower than a refractive index of the core, a portion of a side wall of the optical waveguide forms a cutting face for contacting hair, the cutting face is a portion of the side wall of the cladding and comprises a portion of the cladding that is thinner than the cladding on other portions of the optical waveguide, and the optical waveguide at the cutting face has a refractive index in a range of 1.48-1.56 so as to be equal to or lower than a refractive index of hair and higher than a refractive index of skin. ### Claim 20 (depends on 19) The hair cutting device as claimed in claim 19, wherein the optical waveguide is composed of or comprises silica, fluoride glass, phosphate glass, chalcogenide glass, and/or crown glass. ### Claim 21 (depends on 19) The hair cutting device as claimed in claim 19, wherein the refractive index of the core is lower than or equal to the refractive index of the hair and higher than the refractive index of the skin. ### Claim 22 (depends on 19) The hair cutting device as claimed in claim 19, wherein the optical waveguide is a D-shape optical waveguide or a polished optical waveguide. ### Claim 23 (depends on 19) The hair cutting device as claimed in claim 19, wherein the refractive index of the optical waveguide at the cutting face is in the range of 1.48-1.54.