# US 2019/0170992 A1 · Method of and microscope with installation for focus stabilization > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0170992 A1 - Document ID: US20190170992A1 - Status: Published application - Kind: A1 - Application number: 16/272,035 - Filed: 2019-02-11 - Published: 2019-06-06 - Earliest claimed: 2016-08-25 - Assignees: Deutsches Krebsforschungszentrum - Applicants: Deutsches Krebsforschungszentrum - Inventors: Johann Engelhardt - Web page: https://patentgrep.com/patent/US20190170992A1 ## CPC - G02B 21/245: {using auxiliary sources, detectors} - G01B 11/002: {for measuring two or more coordinates} - G01B 11/14: for measuring distance or clearance between spaced objects or spaced apertures (G01B11/26 takes precedence; rangefinders G01C3/00) - G02B 7/28: Systems for automatic generation of focusing signals - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS ## Abstract In a method of monitoring a relative position of a microscope objective with regard to a sample a test beam of light is directed onto at least one at least partially reflective surface connected to the sample, and light of the test beam reflected at the at least one at least partially reflective surface is registered and evaluated. Additionally, the test beam is directed onto a reflective surface of the microscope objective facing the sample, and light of the test beam reflected at the reflective surface of the microscope objective is also registered and evaluated. ## Claims ### Claim 1 A method of monitoring a relative position of a microscope objective with regard to a sample, the method comprising directing a test beam of light onto at least one at least one partially reflective surface connected to the sample, registering and evaluating first reflected light of the test beam that is reflected at the at least one at least one partially reflective surface, also directing the test beam onto a reflective surface of the microscope objective facing the sample, and registering and evaluating second reflected light of the test beam that is reflected at the reflective surface of the microscope objective, wherein the test beam is directed from a side of the sample facing away from the microscope objective through the at least one partially reflective surface connected to the sample onto the reflective surface of the microscope objective, and wherein the first reflected light and the second reflected light are both registered at that side of the sample facing away from the microscope objective. ### Claim 2 (depends on 1) The method of claim 1, wherein the first reflected light and the second reflected light are both registered with a camera located at that side of the sample facing away from the microscope objective. ### Claim 3 (depends on 1) The method of claim 1, wherein the test beam is a beam of coherent light, wherein the first reflected light and the second reflected light at least partially overlap with each other when being registered. ### Claim 4 (depends on 1) The method of claim 1, wherein at least one of the at least one at least partially reflective surface connected to the sample and the reflective surface of the microscope objective is spatially structured. ### Claim 5 (depends on 1) The method of claim 1, wherein the at least one at least partially reflective surface connected to the sample is selected from a surface of a microscope slide and a surface of a cover slip. ### Claim 6 (depends on 1) The method of claim 1, wherein the reflective surface of the microscope objective is a surface of a metal frame holding a front lens of the microscope objective. ### Claim 7 (depends on 1) The method of claim 1, wherein the light of the test beam differs in wave length from every light directed through the microscope objective into the sample. ### Claim 8 (depends on 7) The method of claim 7, wherein the first reflected light and the second reflected light are filtered with a wavelength filter prior to being registered. ### Claim 9 (depends on 1) The method of claim 1, wherein a light intensity distribution of the first reflected light and the second reflected light is registered and compared to at least one reference light intensity distribution. ### Claim 10 (depends on 9) The method of claim 9, wherein the at least one reference light intensity distribution is a previously registered light intensity distribution of the first reflected light and the second reflected light. ### Claim 11 (depends on 10) The method of claim 10, wherein the at least one reference light intensity distribution is one of a series of light intensity distributions of the first reflected light and the second reflected light previously registered under defined relative positions of the microscope objective with regard to the sample. ### Claim 12 (depends on 1) The method of claim 1, wherein variations of the first reflected light and the second reflected light are compensated for by relocating the microscope objective with regard to the sample. ### Claim 13 A microscope comprising a microscope objective, a microscope slide configured to hold a sample, and an installation for monitoring a relative position of the microscope objective with regard to the sample, the installation comprising a light source configured to direct a test beam of light onto at least one at least one partially reflective surface connected to the microscope slide, and a detector configured to register first reflected light of the test beam that is reflected at the at least one surface, wherein the light source is configured to also direct the test beam onto a reflective surface of the microscope objective facing the sample, wherein the detector is configured to also register second reflected light of the test beam reflected at the reflective surface of the microscope objective, wherein the light source and the detector are both arranged at a side of the microscope slide facing away from the microscope objective, and wherein the light source is configured to direct the test beam through the at least one partially reflective surface connected to the microscope slide onto the reflective surface of the microscope objective. ### Claim 14 (depends on 13) The microscope of claim 13, wherein the light source includes a laser diode providing the test beam as a laser beam. ### Claim 15 (depends on 13) The microscope of claim 13, wherein the detector includes a camera comprising at least 100 by 100 pixels. ### Claim 16 (depends on 13) The microscope of claim 13, wherein the detector is operatively connected to a controller of a slide stage configured to position the microscope slide with regard to the microscope objective.