# US 10,478,053 B2 · Endoscope illumination device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,478,053 B2 - Document ID: US10478053B2 - Status: Granted - Kind: B2 - Application number: 15/947,176 - Filed: 2018-04-06 - Published: 2018-08-16 - Granted: 2019-11-19 - Earliest claimed: 2015-10-07 - Assignees: Olympus Corporation - Applicants: Olympus Corporation - Inventors: Satoshi Ohara - Web page: https://patentgrep.com/patent/US10478053B2 ## CPC - A61B 1/0653: {with wavelength conversion} - A61B 1/0638: {providing two or more wavelengths} - A61B 1/0661: {Endoscope light sources} - A61B 1/07: using light-conductive means, e.g. optical fibres - G02B 6/0008: {the light being emitted at the end of the fibre} - G02B 6/02: Optical fibres with cladding {with or without a coating} - G02B 6/02038: {with core or cladding having graded refractive index} - A61B 1/043: {for fluorescence imaging} - A61B 1/0684: {using light emitting diodes [LED]} - G01N 21/6456: {Spatial resolved fluorescence measurements; Imaging} - G01N 2021/6484: {Optical fibres} - G01N 2201/0612: Laser diodes - G02B 6/4296: {coupling with sources of high radiant energy, e.g. high power lasers, high temperature light sources} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - 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) ## Abstract An endoscope illumination device includes a light source that outputs primary light, a light guide that includes a first end face from which the primary light is radiated, and guides the primary light, and a light converter that is disposed to face the first end face, includes a second end face which the primary light enters, converts part of the primary light into secondary light. The illumination device also includes a holder that holds the light guide and the light converter so that an incident angle of the secondary light that is radiated from a point of intersection of the second end face and an optical axis of the light guide on the first end face and enters the first end face is equal to or larger than an acceptance angle (NA) of the light guide. ## Claims ### Claim 1 An endoscope illumination device, comprising: a light source that outputs primary light; a light guide that includes a first end face from which the primary light is radiated, and guides the primary light; a light converter that is disposed to face the first end face, includes a second end face that the primary light enters, converts part of the primary light into secondary light; and a holder that holds the light guide and the light converter so that an incident angle of the secondary light that is radiated from a point of intersection of the second end face and an optical axis of the light guide on the first end face and enters the first end face is equal to or larger than an acceptance angle (NA) of the light guide. ### Claim 2 (depends on 1) The endoscope illumination device according to claim 1, wherein, where a radius of a light guiding path cross section of the light guide is d, the acceptance angle of the light guide is NA, a refractive index of a medium between the first end face and the second end face is n, and a distance between the first end face and the second end face is L, the distance L between the first end face and the second end face satisfies L ≤ d × n × 1 - ( NA n ) 2 NA ### Claim 3 (depends on 1) The endoscope illumination device according to claim 1, further comprising an interval keeping member that defines the distance between the first end face and the second end face. ### Claim 4 (depends on 3) The endoscope illumination device according to claim 3, wherein the interval keeping member is a transparent member interposed between the light guide and the light converter. ### Claim 5 (depends on 3) The endoscope illumination device according to claim 3, wherein the holder includes a light guide holding hole into which the light guide is inserted and a light converter holding hole into which the light converter is inserted, the light guide holding hole communicates with the light converter holding hole, and the light converter holding hole has a tapered shape in which a hole diameter gradually increases from the light guide holding hole side. ### Claim 6 (depends on 5) The endoscope illumination device according to claim 5, wherein the first end face inserted into the holder is in the light converter holding hole. ### Claim 7 (depends on 1) The endoscope illumination device according to claim 1, wherein a transparent member is filled between the first end face and the second end face, the transparent member being optically transparent with respect to the primary light and the secondary light. ### Claim 8 (depends on 7) The endoscope illumination device according to claim 7, wherein the first end face is convex, and a refractive index of the transparent member is lower than a refractive index of the light guide, or the first end face is concave, and the refractive index of the transparent member is higher than the refractive index of the light guide. ### Claim 9 (depends on 7) The endoscope illumination device according to claim 7, wherein the second end face is convex, and a refractive index of the transparent member is lower than a refractive index of the light converter, or the second end face is concave, and the refractive index of the transparent member is higher than the refractive index of the light converter. ### Claim 10 (depends on 1) The endoscope illumination device according to claim 1, wherein the light guide is a multi-mode optical fiber configured to guide light in multiple modes. ### Claim 11 (depends on 10) The endoscope illumination device according to claim 10, wherein the optical fiber includes a core and a clad covering an outer peripheral cylindrical surface of the core, and a diameter of the clad is 1.2 times a diameter of the core or less. ### Claim 12 (depends on 10) The endoscope illumination device according to claim 10, wherein the optical fiber is a double-clad fiber including a core, a primary clad covering an outer peripheral cylindrical surface of the core, and a secondary clad covering an outer peripheral cylindrical surface of the primary clad. ### Claim 13 (depends on 12) The endoscope illumination device according to claim 12, wherein the primary light is guided in the core, and the secondary light is guided in the core and the primary clad. ### Claim 14 (depends on 10) The endoscope illumination device according to claim 10, wherein the optical fiber is an optical fiber including a core, a clad covering an outer peripheral cylindrical surface of the core, and a metal reflection film covering an outer peripheral cylindrical surface of the clad, and the metal reflection film has reflectivity with respect to both the primary light and the secondary light. ### Claim 15 (depends on 14) The endoscope illumination device according to claim 14, wherein the primary light is guided in the core, and the secondary light is guided in the core and the clad. ### Claim 16 (depends on 1) The endoscope illumination device according to claim 1, wherein the light converter is columnar, and has such a diameter as to provide an area allowing all the primary light radiated from the first end face to be applied to the light converter. ### Claim 17 (depends on 16) The endoscope illumination device according to claim 16, wherein the light converter includes a fluorescent substance. ### Claim 18 (depends on 1) The endoscope illumination device according to claim 1, further comprising a branching member that splits, from the primary light, return light guided by the light guide opposite in direction to travel of the primary light. ### Claim 19 (depends on 18) The endoscope illumination device according to claim 18, wherein the branching member is a dichroic mirror or an optical coupler. ### Claim 20 (depends on 18) The endoscope illumination device according to claim 18, further comprising a detection section that detects a light quantity of the return light guided by the light guide opposite in direction to travel of the primary light. ### Claim 21 (depends on 20) The endoscope illumination device according to claim 20, further comprising a control section that controls the light source based on the light quantity of the return light. ### Claim 22 (depends on 21) The endoscope illumination device according to claim 21, wherein the control section makes an output light quantity of the light source zero when the control section determines that a failure has occurred based on a detection result of the light quantity of the return light. ### Claim 23 (depends on 21) The endoscope illumination device according to claim 21, wherein the control section makes an output light quantity of the light source lower than in normal use when the control section determines that a failure has occurred based on a detection result of the light quantity of the return light. ### Claim 24 (depends on 1) The endoscope illumination device according to claim 1, wherein the holder includes a light guide holding hole into which the light guide is inserted and a light converter holding hole into which the light converter is inserted, and the light guide holding hole communicates with the light converter holding hole, further comprising a transparent member provided in the light converter holding hole of the holder.