# US 11,298,015 B2 · Illuminating system for determining the topography of the cornea of an eye > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,298,015 B2 - Document ID: US11298015B2 - Status: Granted - Kind: B2 - Application number: 16/330,079 - Filed: 2017-08-31 - Published: 2019-08-15 - Granted: 2022-04-12 - Earliest claimed: 2016-09-02 - Assignees: Carl Zeiss Meditec AG - Applicants: Carl Zeiss Meditec AG - Inventors: Beate Böhme; Rico Fuchs; Günter Rudolph - Web page: https://patentgrep.com/patent/US11298015B2 ## CPC - A61B 3/107: for determining the shape or measuring the curvature of the cornea - A61B 3/0008: {provided with illuminating means (A61B3/117, A61B3/14 take precedence)} - G01B 11/2513: {with several lines being projected in more than one direction, e.g. grids, patterns} - A61B 3/1005: {for measuring distances inside the eye, e.g. thickness of the cornea (A61B3/11 takes precedence)} - A61B 3/103: for determining refraction, e.g. refractometers or skiascopes - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS ## Abstract An illumination system for producing an illumination pattern for measuring the cornea of an eye and, in particular, for determining the topography thereof and in so doing facilitating distance-independent measurements. The illumination system according to the invention for determining the topography of the cornea of an eye includes an illumination unit and a unit for producing an illumination pattern, wherein the illumination unit includes a plurality of illumination modules. A lens array which produces a spatially distributed, collimated illumination pattern is used as a unit for producing an illumination pattern. The illumination system produces an illumination pattern, by which the topography of the cornea of an eye can be determined. Here, the illumination system is designed as a compact module, and so it can be easily combined with other measurement systems, without colliding with the beam paths thereof. ## Claims ### Claim 1 An illumination system for determining the topography of the cornea of an eye, comprising: an illumination unit that is configured to provide illumination outside of a central region surrounding an optical axis thereby enabling telecentric axially symmetric detection and a unit that produces an illumination pattern; wherein the illumination unit comprises a plurality of illumination modules, each of the plurality of illumination modules including a light source and at least one reflective or refractive optical element that images the light source toward the eye; and wherein the unit that produces the illumination pattern comprises a lens array which produces a spatially distributed, collimated illumination pattern outside of the central region. ### Claim 2 (depends on 1) The illumination system as claimed in claim 1, wherein the lens array comprises diverging lenses with a negative focal length. ### Claim 3 (depends on 1) The illumination system as claimed in claim 1, wherein the illumination unit comprises at least two of the illumination modules. ### Claim 4 (depends on 3) The illumination system as claimed in claim 3, wherein the illumination unit comprises at least four of the illumination modules. ### Claim 5 (depends on 3) The illumination system as claimed in claim 3, wherein the illumination unit comprises at least six of the illumination modules. ### Claim 6 (depends on 1) The illumination system as claimed in claim 1, wherein the illumination modules are arranged in such a way that the illumination light of each illumination module illuminates part of the unit for producing an illumination pattern. ### Claim 7 (depends on 1) The illumination system as claimed in claim 1, wherein each illumination module comprises at least one reflective or refractive optical element in addition to a light source to image the light source into the eye by way of the lens array. ### Claim 8 (depends on 1) The illumination system as claimed in claim 1, wherein each illumination module comprises an asphere as a refractive optical element in order to image the light source into the eye by way of the lens array. ### Claim 9 (depends on 1) The illumination system as claimed in claim 1, wherein each illumination module comprises a Fresnel lens as a refractive optical element to image the light source into the eye by way of the lens array. ### Claim 10 An illumination system for determining the topography of the cornea of an eye, comprising: an illumination unit and a unit that produces an illumination pattern; wherein the illumination unit comprises a plurality of illumination modules; and the unit for producing an illumination pattern comprises a lens array which produces a spatially distributed, collimated illumination pattern; wherein each illumination module comprises an elliptical reflector as a reflective optical element to image the light source into the eye by way of the lens array, wherein the light source is situated at a first focus of the elliptical reflector and the eye is situated at a second focus of the elliptical reflector. ### Claim 11 (depends on 1) The illumination system as claimed in claim 1, wherein each of the illumination modules comprises a separate lens array. ### Claim 12 (depends on 1) The illumination system as claimed in claim 1, wherein the individual lenses of the lens array are arranged in a rectangular grid, a radially symmetric grid or a hexagonal grid on a spherical surface that is concentric with the eye. ### Claim 13 (depends on 1) The illumination system as claimed in claim 1, wherein the individual lenses of the lens array are arranged in a rectangular grid, a radially symmetric grid or a hexagonal grid on a plane surface. ### Claim 14 (depends on 12) The illumination system as claimed in claim 12, wherein the individual lenses of the lens array are aligned in such a way that the optical axes thereof intersect at a common center in the eye. ### Claim 15 (depends on 1) The illumination system is claimed in claim 1, wherein individual lenses of the lens array have a negative focal length which, in terms of magnitude, deviates by less than 15% from the distance between the cornea being illuminated and the lens array. ### Claim 16 (depends on 15) The illumination system is claimed in claim 15, wherein individual lenses of the lens array have a negative focal length which, in terms of magnitude, deviates by less than 10% from the distance between the cornea being illuminated and the lens array. ### Claim 17 (depends on 15) The illumination system is claimed in claim 15, wherein individual lenses of the lens array have a negative focal length which, in terms of magnitude, deviates by less than 5% from the distance between the cornea being illuminated and the lens array. ### Claim 18 (depends on 11) The illumination system as claimed in claim 11, wherein individual lenses are arranged on a side of the lens array facing away from the eye and a basic form of the lens array lies concentrically around the optical axis. ### Claim 19 (depends on 1) The illumination system as claimed in claim 1, wherein the lens array comprises an injection molded part.